feat: add auth

pento/config/test.exs

@@ -1,5 +1,8 @@
 import Config
 
+# Only in tests, remove the complexity from the password hashing algorithm
+config :bcrypt_elixir, :log_rounds, 1
+
 # Configure your database
 #
 # The MIX_TEST_PARTITION environment variable can be used

pento/lib/pento/accounts.ex

@@ -0,0 +1,353 @@
+defmodule Pento.Accounts do
+  @moduledoc """
+  The Accounts context.
+  """
+
+  import Ecto.Query, warn: false
+  alias Pento.Repo
+
+  alias Pento.Accounts.{User, UserToken, UserNotifier}
+
+  ## Database getters
+
+  @doc """
+  Gets a user by email.
+
+  ## Examples
+
+      iex> get_user_by_email("foo@example.com")
+      %User{}
+
+      iex> get_user_by_email("unknown@example.com")
+      nil
+
+  """
+  def get_user_by_email(email) when is_binary(email) do
+    Repo.get_by(User, email: email)
+  end
+
+  @doc """
+  Gets a user by email and password.
+
+  ## Examples
+
+      iex> get_user_by_email_and_password("foo@example.com", "correct_password")
+      %User{}
+
+      iex> get_user_by_email_and_password("foo@example.com", "invalid_password")
+      nil
+
+  """
+  def get_user_by_email_and_password(email, password)
+      when is_binary(email) and is_binary(password) do
+    user = Repo.get_by(User, email: email)
+    if User.valid_password?(user, password), do: user
+  end
+
+  @doc """
+  Gets a single user.
+
+  Raises `Ecto.NoResultsError` if the User does not exist.
+
+  ## Examples
+
+      iex> get_user!(123)
+      %User{}
+
+      iex> get_user!(456)
+      ** (Ecto.NoResultsError)
+
+  """
+  def get_user!(id), do: Repo.get!(User, id)
+
+  ## User registration
+
+  @doc """
+  Registers a user.
+
+  ## Examples
+
+      iex> register_user(%{field: value})
+      {:ok, %User{}}
+
+      iex> register_user(%{field: bad_value})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def register_user(attrs) do
+    %User{}
+    |> User.registration_changeset(attrs)
+    |> Repo.insert()
+  end
+
+  @doc """
+  Returns an `%Ecto.Changeset{}` for tracking user changes.
+
+  ## Examples
+
+      iex> change_user_registration(user)
+      %Ecto.Changeset{data: %User{}}
+
+  """
+  def change_user_registration(%User{} = user, attrs \\ %{}) do
+    User.registration_changeset(user, attrs, hash_password: false, validate_email: false)
+  end
+
+  ## Settings
+
+  @doc """
+  Returns an `%Ecto.Changeset{}` for changing the user email.
+
+  ## Examples
+
+      iex> change_user_email(user)
+      %Ecto.Changeset{data: %User{}}
+
+  """
+  def change_user_email(user, attrs \\ %{}) do
+    User.email_changeset(user, attrs, validate_email: false)
+  end
+
+  @doc """
+  Emulates that the email will change without actually changing
+  it in the database.
+
+  ## Examples
+
+      iex> apply_user_email(user, "valid password", %{email: ...})
+      {:ok, %User{}}
+
+      iex> apply_user_email(user, "invalid password", %{email: ...})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def apply_user_email(user, password, attrs) do
+    user
+    |> User.email_changeset(attrs)
+    |> User.validate_current_password(password)
+    |> Ecto.Changeset.apply_action(:update)
+  end
+
+  @doc """
+  Updates the user email using the given token.
+
+  If the token matches, the user email is updated and the token is deleted.
+  The confirmed_at date is also updated to the current time.
+  """
+  def update_user_email(user, token) do
+    context = "change:#{user.email}"
+
+    with {:ok, query} <- UserToken.verify_change_email_token_query(token, context),
+         %UserToken{sent_to: email} <- Repo.one(query),
+         {:ok, _} <- Repo.transaction(user_email_multi(user, email, context)) do
+      :ok
+    else
+      _ -> :error
+    end
+  end
+
+  defp user_email_multi(user, email, context) do
+    changeset =
+      user
+      |> User.email_changeset(%{email: email})
+      |> User.confirm_changeset()
+
+    Ecto.Multi.new()
+    |> Ecto.Multi.update(:user, changeset)
+    |> Ecto.Multi.delete_all(:tokens, UserToken.by_user_and_contexts_query(user, [context]))
+  end
+
+  @doc ~S"""
+  Delivers the update email instructions to the given user.
+
+  ## Examples
+
+      iex> deliver_user_update_email_instructions(user, current_email, &url(~p"/users/settings/confirm_email/#{&1}"))
+      {:ok, %{to: ..., body: ...}}
+
+  """
+  def deliver_user_update_email_instructions(%User{} = user, current_email, update_email_url_fun)
+      when is_function(update_email_url_fun, 1) do
+    {encoded_token, user_token} = UserToken.build_email_token(user, "change:#{current_email}")
+
+    Repo.insert!(user_token)
+    UserNotifier.deliver_update_email_instructions(user, update_email_url_fun.(encoded_token))
+  end
+
+  @doc """
+  Returns an `%Ecto.Changeset{}` for changing the user password.
+
+  ## Examples
+
+      iex> change_user_password(user)
+      %Ecto.Changeset{data: %User{}}
+
+  """
+  def change_user_password(user, attrs \\ %{}) do
+    User.password_changeset(user, attrs, hash_password: false)
+  end
+
+  @doc """
+  Updates the user password.
+
+  ## Examples
+
+      iex> update_user_password(user, "valid password", %{password: ...})
+      {:ok, %User{}}
+
+      iex> update_user_password(user, "invalid password", %{password: ...})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def update_user_password(user, password, attrs) do
+    changeset =
+      user
+      |> User.password_changeset(attrs)
+      |> User.validate_current_password(password)
+
+    Ecto.Multi.new()
+    |> Ecto.Multi.update(:user, changeset)
+    |> Ecto.Multi.delete_all(:tokens, UserToken.by_user_and_contexts_query(user, :all))
+    |> Repo.transaction()
+    |> case do
+      {:ok, %{user: user}} -> {:ok, user}
+      {:error, :user, changeset, _} -> {:error, changeset}
+    end
+  end
+
+  ## Session
+
+  @doc """
+  Generates a session token.
+  """
+  def generate_user_session_token(user) do
+    {token, user_token} = UserToken.build_session_token(user)
+    Repo.insert!(user_token)
+    token
+  end
+
+  @doc """
+  Gets the user with the given signed token.
+  """
+  def get_user_by_session_token(token) do
+    {:ok, query} = UserToken.verify_session_token_query(token)
+    Repo.one(query)
+  end
+
+  @doc """
+  Deletes the signed token with the given context.
+  """
+  def delete_user_session_token(token) do
+    Repo.delete_all(UserToken.by_token_and_context_query(token, "session"))
+    :ok
+  end
+
+  ## Confirmation
+
+  @doc ~S"""
+  Delivers the confirmation email instructions to the given user.
+
+  ## Examples
+
+      iex> deliver_user_confirmation_instructions(user, &url(~p"/users/confirm/#{&1}"))
+      {:ok, %{to: ..., body: ...}}
+
+      iex> deliver_user_confirmation_instructions(confirmed_user, &url(~p"/users/confirm/#{&1}"))
+      {:error, :already_confirmed}
+
+  """
+  def deliver_user_confirmation_instructions(%User{} = user, confirmation_url_fun)
+      when is_function(confirmation_url_fun, 1) do
+    if user.confirmed_at do
+      {:error, :already_confirmed}
+    else
+      {encoded_token, user_token} = UserToken.build_email_token(user, "confirm")
+      Repo.insert!(user_token)
+      UserNotifier.deliver_confirmation_instructions(user, confirmation_url_fun.(encoded_token))
+    end
+  end
+
+  @doc """
+  Confirms a user by the given token.
+
+  If the token matches, the user account is marked as confirmed
+  and the token is deleted.
+  """
+  def confirm_user(token) do
+    with {:ok, query} <- UserToken.verify_email_token_query(token, "confirm"),
+         %User{} = user <- Repo.one(query),
+         {:ok, %{user: user}} <- Repo.transaction(confirm_user_multi(user)) do
+      {:ok, user}
+    else
+      _ -> :error
+    end
+  end
+
+  defp confirm_user_multi(user) do
+    Ecto.Multi.new()
+    |> Ecto.Multi.update(:user, User.confirm_changeset(user))
+    |> Ecto.Multi.delete_all(:tokens, UserToken.by_user_and_contexts_query(user, ["confirm"]))
+  end
+
+  ## Reset password
+
+  @doc ~S"""
+  Delivers the reset password email to the given user.
+
+  ## Examples
+
+      iex> deliver_user_reset_password_instructions(user, &url(~p"/users/reset_password/#{&1}"))
+      {:ok, %{to: ..., body: ...}}
+
+  """
+  def deliver_user_reset_password_instructions(%User{} = user, reset_password_url_fun)
+      when is_function(reset_password_url_fun, 1) do
+    {encoded_token, user_token} = UserToken.build_email_token(user, "reset_password")
+    Repo.insert!(user_token)
+    UserNotifier.deliver_reset_password_instructions(user, reset_password_url_fun.(encoded_token))
+  end
+
+  @doc """
+  Gets the user by reset password token.
+
+  ## Examples
+
+      iex> get_user_by_reset_password_token("validtoken")
+      %User{}
+
+      iex> get_user_by_reset_password_token("invalidtoken")
+      nil
+
+  """
+  def get_user_by_reset_password_token(token) do
+    with {:ok, query} <- UserToken.verify_email_token_query(token, "reset_password"),
+         %User{} = user <- Repo.one(query) do
+      user
+    else
+      _ -> nil
+    end
+  end
+
+  @doc """
+  Resets the user password.
+
+  ## Examples
+
+      iex> reset_user_password(user, %{password: "new long password", password_confirmation: "new long password"})
+      {:ok, %User{}}
+
+      iex> reset_user_password(user, %{password: "valid", password_confirmation: "not the same"})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def reset_user_password(user, attrs) do
+    Ecto.Multi.new()
+    |> Ecto.Multi.update(:user, User.password_changeset(user, attrs))
+    |> Ecto.Multi.delete_all(:tokens, UserToken.by_user_and_contexts_query(user, :all))
+    |> Repo.transaction()
+    |> case do
+      {:ok, %{user: user}} -> {:ok, user}
+      {:error, :user, changeset, _} -> {:error, changeset}
+    end
+  end
+end

pento/lib/pento/accounts/user.ex

@@ -0,0 +1,161 @@
+defmodule Pento.Accounts.User do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  schema "users" do
+    field :email, :string
+    field :password, :string, virtual: true, redact: true
+    field :hashed_password, :string, redact: true
+    field :current_password, :string, virtual: true, redact: true
+    field :confirmed_at, :utc_datetime
+
+    timestamps(type: :utc_datetime)
+  end
+
+  @doc """
+  A user changeset for registration.
+
+  It is important to validate the length of both email and password.
+  Otherwise databases may truncate the email without warnings, which
+  could lead to unpredictable or insecure behaviour. Long passwords may
+  also be very expensive to hash for certain algorithms.
+
+  ## Options
+
+    * `:hash_password` - Hashes the password so it can be stored securely
+      in the database and ensures the password field is cleared to prevent
+      leaks in the logs. If password hashing is not needed and clearing the
+      password field is not desired (like when using this changeset for
+      validations on a LiveView form), this option can be set to `false`.
+      Defaults to `true`.
+
+    * `:validate_email` - Validates the uniqueness of the email, in case
+      you don't want to validate the uniqueness of the email (like when
+      using this changeset for validations on a LiveView form before
+      submitting the form), this option can be set to `false`.
+      Defaults to `true`.
+  """
+  def registration_changeset(user, attrs, opts \\ []) do
+    user
+    |> cast(attrs, [:email, :password])
+    |> validate_email(opts)
+    |> validate_password(opts)
+  end
+
+  defp validate_email(changeset, opts) do
+    changeset
+    |> validate_required([:email])
+    |> validate_format(:email, ~r/^[^\s]+@[^\s]+$/, message: "must have the @ sign and no spaces")
+    |> validate_length(:email, max: 160)
+    |> maybe_validate_unique_email(opts)
+  end
+
+  defp validate_password(changeset, opts) do
+    changeset
+    |> validate_required([:password])
+    |> validate_length(:password, min: 12, max: 72)
+    # Examples of additional password validation:
+    # |> validate_format(:password, ~r/[a-z]/, message: "at least one lower case character")
+    # |> validate_format(:password, ~r/[A-Z]/, message: "at least one upper case character")
+    # |> validate_format(:password, ~r/[!?@#$%^&*_0-9]/, message: "at least one digit or punctuation character")
+    |> maybe_hash_password(opts)
+  end
+
+  defp maybe_hash_password(changeset, opts) do
+    hash_password? = Keyword.get(opts, :hash_password, true)
+    password = get_change(changeset, :password)
+
+    if hash_password? && password && changeset.valid? do
+      changeset
+      # If using Bcrypt, then further validate it is at most 72 bytes long
+      |> validate_length(:password, max: 72, count: :bytes)
+      # Hashing could be done with `Ecto.Changeset.prepare_changes/2`, but that
+      # would keep the database transaction open longer and hurt performance.
+      |> put_change(:hashed_password, Bcrypt.hash_pwd_salt(password))
+      |> delete_change(:password)
+    else
+      changeset
+    end
+  end
+
+  defp maybe_validate_unique_email(changeset, opts) do
+    if Keyword.get(opts, :validate_email, true) do
+      changeset
+      |> unsafe_validate_unique(:email, Pento.Repo)
+      |> unique_constraint(:email)
+    else
+      changeset
+    end
+  end
+
+  @doc """
+  A user changeset for changing the email.
+
+  It requires the email to change otherwise an error is added.
+  """
+  def email_changeset(user, attrs, opts \\ []) do
+    user
+    |> cast(attrs, [:email])
+    |> validate_email(opts)
+    |> case do
+      %{changes: %{email: _}} = changeset -> changeset
+      %{} = changeset -> add_error(changeset, :email, "did not change")
+    end
+  end
+
+  @doc """
+  A user changeset for changing the password.
+
+  ## Options
+
+    * `:hash_password` - Hashes the password so it can be stored securely
+      in the database and ensures the password field is cleared to prevent
+      leaks in the logs. If password hashing is not needed and clearing the
+      password field is not desired (like when using this changeset for
+      validations on a LiveView form), this option can be set to `false`.
+      Defaults to `true`.
+  """
+  def password_changeset(user, attrs, opts \\ []) do
+    user
+    |> cast(attrs, [:password])
+    |> validate_confirmation(:password, message: "does not match password")
+    |> validate_password(opts)
+  end
+
+  @doc """
+  Confirms the account by setting `confirmed_at`.
+  """
+  def confirm_changeset(user) do
+    now = DateTime.utc_now() |> DateTime.truncate(:second)
+    change(user, confirmed_at: now)
+  end
+
+  @doc """
+  Verifies the password.
+
+  If there is no user or the user doesn't have a password, we call
+  `Bcrypt.no_user_verify/0` to avoid timing attacks.
+  """
+  def valid_password?(%Pento.Accounts.User{hashed_password: hashed_password}, password)
+      when is_binary(hashed_password) and byte_size(password) > 0 do
+    Bcrypt.verify_pass(password, hashed_password)
+  end
+
+  def valid_password?(_, _) do
+    Bcrypt.no_user_verify()
+    false
+  end
+
+  @doc """
+  Validates the current password otherwise adds an error to the changeset.
+  """
+  def validate_current_password(changeset, password) do
+    changeset = cast(changeset, %{current_password: password}, [:current_password])
+
+    if valid_password?(changeset.data, password) do
+      changeset
+    else
+      add_error(changeset, :current_password, "is not valid")
+    end
+  end
+end

pento/lib/pento/accounts/user_notifier.ex

@@ -0,0 +1,79 @@
+defmodule Pento.Accounts.UserNotifier do
+  import Swoosh.Email
+
+  alias Pento.Mailer
+
+  # Delivers the email using the application mailer.
+  defp deliver(recipient, subject, body) do
+    email =
+      new()
+      |> to(recipient)
+      |> from({"Pento", "contact@example.com"})
+      |> subject(subject)
+      |> text_body(body)
+
+    with {:ok, _metadata} <- Mailer.deliver(email) do
+      {:ok, email}
+    end
+  end
+
+  @doc """
+  Deliver instructions to confirm account.
+  """
+  def deliver_confirmation_instructions(user, url) do
+    deliver(user.email, "Confirmation instructions", """
+
+    ==============================
+
+    Hi #{user.email},
+
+    You can confirm your account by visiting the URL below:
+
+    #{url}
+
+    If you didn't create an account with us, please ignore this.
+
+    ==============================
+    """)
+  end
+
+  @doc """
+  Deliver instructions to reset a user password.
+  """
+  def deliver_reset_password_instructions(user, url) do
+    deliver(user.email, "Reset password instructions", """
+
+    ==============================
+
+    Hi #{user.email},
+
+    You can reset your password by visiting the URL below:
+
+    #{url}
+
+    If you didn't request this change, please ignore this.
+
+    ==============================
+    """)
+  end
+
+  @doc """
+  Deliver instructions to update a user email.
+  """
+  def deliver_update_email_instructions(user, url) do
+    deliver(user.email, "Update email instructions", """
+
+    ==============================
+
+    Hi #{user.email},
+
+    You can change your email by visiting the URL below:
+
+    #{url}
+
+    If you didn't request this change, please ignore this.
+
+    ==============================
+    """)
+  end
+end

pento/lib/pento/accounts/user_token.ex

@@ -0,0 +1,179 @@
+defmodule Pento.Accounts.UserToken do
+  use Ecto.Schema
+  import Ecto.Query
+  alias Pento.Accounts.UserToken
+
+  @hash_algorithm :sha256
+  @rand_size 32
+
+  # It is very important to keep the reset password token expiry short,
+  # since someone with access to the email may take over the account.
+  @reset_password_validity_in_days 1
+  @confirm_validity_in_days 7
+  @change_email_validity_in_days 7
+  @session_validity_in_days 60
+
+  schema "users_tokens" do
+    field :token, :binary
+    field :context, :string
+    field :sent_to, :string
+    belongs_to :user, Pento.Accounts.User
+
+    timestamps(type: :utc_datetime, updated_at: false)
+  end
+
+  @doc """
+  Generates a token that will be stored in a signed place,
+  such as session or cookie. As they are signed, those
+  tokens do not need to be hashed.
+
+  The reason why we store session tokens in the database, even
+  though Phoenix already provides a session cookie, is because
+  Phoenix' default session cookies are not persisted, they are
+  simply signed and potentially encrypted. This means they are
+  valid indefinitely, unless you change the signing/encryption
+  salt.
+
+  Therefore, storing them allows individual user
+  sessions to be expired. The token system can also be extended
+  to store additional data, such as the device used for logging in.
+  You could then use this information to display all valid sessions
+  and devices in the UI and allow users to explicitly expire any
+  session they deem invalid.
+  """
+  def build_session_token(user) do
+    token = :crypto.strong_rand_bytes(@rand_size)
+    {token, %UserToken{token: token, context: "session", user_id: user.id}}
+  end
+
+  @doc """
+  Checks if the token is valid and returns its underlying lookup query.
+
+  The query returns the user found by the token, if any.
+
+  The token is valid if it matches the value in the database and it has
+  not expired (after @session_validity_in_days).
+  """
+  def verify_session_token_query(token) do
+    query =
+      from token in by_token_and_context_query(token, "session"),
+        join: user in assoc(token, :user),
+        where: token.inserted_at > ago(@session_validity_in_days, "day"),
+        select: user
+
+    {:ok, query}
+  end
+
+  @doc """
+  Builds a token and its hash to be delivered to the user's email.
+
+  The non-hashed token is sent to the user email while the
+  hashed part is stored in the database. The original token cannot be reconstructed,
+  which means anyone with read-only access to the database cannot directly use
+  the token in the application to gain access. Furthermore, if the user changes
+  their email in the system, the tokens sent to the previous email are no longer
+  valid.
+
+  Users can easily adapt the existing code to provide other types of delivery methods,
+  for example, by phone numbers.
+  """
+  def build_email_token(user, context) do
+    build_hashed_token(user, context, user.email)
+  end
+
+  defp build_hashed_token(user, context, sent_to) do
+    token = :crypto.strong_rand_bytes(@rand_size)
+    hashed_token = :crypto.hash(@hash_algorithm, token)
+
+    {Base.url_encode64(token, padding: false),
+     %UserToken{
+       token: hashed_token,
+       context: context,
+       sent_to: sent_to,
+       user_id: user.id
+     }}
+  end
+
+  @doc """
+  Checks if the token is valid and returns its underlying lookup query.
+
+  The query returns the user found by the token, if any.
+
+  The given token is valid if it matches its hashed counterpart in the
+  database and the user email has not changed. This function also checks
+  if the token is being used within a certain period, depending on the
+  context. The default contexts supported by this function are either
+  "confirm", for account confirmation emails, and "reset_password",
+  for resetting the password. For verifying requests to change the email,
+  see `verify_change_email_token_query/2`.
+  """
+  def verify_email_token_query(token, context) do
+    case Base.url_decode64(token, padding: false) do
+      {:ok, decoded_token} ->
+        hashed_token = :crypto.hash(@hash_algorithm, decoded_token)
+        days = days_for_context(context)
+
+        query =
+          from token in by_token_and_context_query(hashed_token, context),
+            join: user in assoc(token, :user),
+            where: token.inserted_at > ago(^days, "day") and token.sent_to == user.email,
+            select: user
+
+        {:ok, query}
+
+      :error ->
+        :error
+    end
+  end
+
+  defp days_for_context("confirm"), do: @confirm_validity_in_days
+  defp days_for_context("reset_password"), do: @reset_password_validity_in_days
+
+  @doc """
+  Checks if the token is valid and returns its underlying lookup query.
+
+  The query returns the user found by the token, if any.
+
+  This is used to validate requests to change the user
+  email. It is different from `verify_email_token_query/2` precisely because
+  `verify_email_token_query/2` validates the email has not changed, which is
+  the starting point by this function.
+
+  The given token is valid if it matches its hashed counterpart in the
+  database and if it has not expired (after @change_email_validity_in_days).
+  The context must always start with "change:".
+  """
+  def verify_change_email_token_query(token, "change:" <> _ = context) do
+    case Base.url_decode64(token, padding: false) do
+      {:ok, decoded_token} ->
+        hashed_token = :crypto.hash(@hash_algorithm, decoded_token)
+
+        query =
+          from token in by_token_and_context_query(hashed_token, context),
+            where: token.inserted_at > ago(@change_email_validity_in_days, "day")
+
+        {:ok, query}
+
+      :error ->
+        :error
+    end
+  end
+
+  @doc """
+  Returns the token struct for the given token value and context.
+  """
+  def by_token_and_context_query(token, context) do
+    from UserToken, where: [token: ^token, context: ^context]
+  end
+
+  @doc """
+  Gets all tokens for the given user for the given contexts.
+  """
+  def by_user_and_contexts_query(user, :all) do
+    from t in UserToken, where: t.user_id == ^user.id
+  end
+
+  def by_user_and_contexts_query(user, [_ | _] = contexts) do
+    from t in UserToken, where: t.user_id == ^user.id and t.context in ^contexts
+  end
+end

pento/lib/pento_web/components/layouts/root.html.heex

@@ -12,6 +12,47 @@
     </script>
   </head>
   <body class="bg-white">
+    <ul class="relative z-10 flex items-center gap-4 px-4 sm:px-6 lg:px-8 justify-end">
+      <%= if @current_user do %>
+        <li class="text-[0.8125rem] leading-6 text-zinc-900">
+          <%= @current_user.email %>
+        </li>
+        <li>
+          <.link
+            href={~p"/users/settings"}
+            class="text-[0.8125rem] leading-6 text-zinc-900 font-semibold hover:text-zinc-700"
+          >
+            Settings
+          </.link>
+        </li>
+        <li>
+          <.link
+            href={~p"/users/log_out"}
+            method="delete"
+            class="text-[0.8125rem] leading-6 text-zinc-900 font-semibold hover:text-zinc-700"
+          >
+            Log out
+          </.link>
+        </li>
+      <% else %>
+        <li>
+          <.link
+            href={~p"/users/register"}
+            class="text-[0.8125rem] leading-6 text-zinc-900 font-semibold hover:text-zinc-700"
+          >
+            Register
+          </.link>
+        </li>
+        <li>
+          <.link
+            href={~p"/users/log_in"}
+            class="text-[0.8125rem] leading-6 text-zinc-900 font-semibold hover:text-zinc-700"
+          >
+            Log in
+          </.link>
+        </li>
+      <% end %>
+    </ul>
     <%= @inner_content %>
   </body>
 </html>

pento/lib/pento_web/controllers/user_session_controller.ex

@@ -0,0 +1,42 @@
+defmodule PentoWeb.UserSessionController do
+  use PentoWeb, :controller
+
+  alias Pento.Accounts
+  alias PentoWeb.UserAuth
+
+  def create(conn, %{"_action" => "registered"} = params) do
+    create(conn, params, "Account created successfully!")
+  end
+
+  def create(conn, %{"_action" => "password_updated"} = params) do
+    conn
+    |> put_session(:user_return_to, ~p"/users/settings")
+    |> create(params, "Password updated successfully!")
+  end
+
+  def create(conn, params) do
+    create(conn, params, "Welcome back!")
+  end
+
+  defp create(conn, %{"user" => user_params}, info) do
+    %{"email" => email, "password" => password} = user_params
+
+    if user = Accounts.get_user_by_email_and_password(email, password) do
+      conn
+      |> put_flash(:info, info)
+      |> UserAuth.log_in_user(user, user_params)
+    else
+      # In order to prevent user enumeration attacks, don't disclose whether the email is registered.
+      conn
+      |> put_flash(:error, "Invalid email or password")
+      |> put_flash(:email, String.slice(email, 0, 160))
+      |> redirect(to: ~p"/users/log_in")
+    end
+  end
+
+  def delete(conn, _params) do
+    conn
+    |> put_flash(:info, "Logged out successfully.")
+    |> UserAuth.log_out_user()
+  end
+end

pento/lib/pento_web/live/user_confirmation_instructions_live.ex

@@ -0,0 +1,51 @@
+defmodule PentoWeb.UserConfirmationInstructionsLive do
+  use PentoWeb, :live_view
+
+  alias Pento.Accounts
+
+  def render(assigns) do
+    ~H"""
+    <div class="mx-auto max-w-sm">
+      <.header class="text-center">
+        No confirmation instructions received?
+        <:subtitle>We'll send a new confirmation link to your inbox</:subtitle>
+      </.header>
+
+      <.simple_form for={@form} id="resend_confirmation_form" phx-submit="send_instructions">
+        <.input field={@form[:email]} type="email" placeholder="Email" required />
+        <:actions>
+          <.button phx-disable-with="Sending..." class="w-full">
+            Resend confirmation instructions
+          </.button>
+        </:actions>
+      </.simple_form>
+
+      <p class="text-center mt-4">
+        <.link href={~p"/users/register"}>Register</.link>
+        | <.link href={~p"/users/log_in"}>Log in</.link>
+      </p>
+    </div>
+    """
+  end
+
+  def mount(_params, _session, socket) do
+    {:ok, assign(socket, form: to_form(%{}, as: "user"))}
+  end
+
+  def handle_event("send_instructions", %{"user" => %{"email" => email}}, socket) do
+    if user = Accounts.get_user_by_email(email) do
+      Accounts.deliver_user_confirmation_instructions(
+        user,
+        &url(~p"/users/confirm/#{&1}")
+      )
+    end
+
+    info =
+      "If your email is in our system and it has not been confirmed yet, you will receive an email with instructions shortly."
+
+    {:noreply,
+     socket
+     |> put_flash(:info, info)
+     |> redirect(to: ~p"/")}
+  end
+end

pento/lib/pento_web/live/user_confirmation_live.ex

@@ -0,0 +1,58 @@
+defmodule PentoWeb.UserConfirmationLive do
+  use PentoWeb, :live_view
+
+  alias Pento.Accounts
+
+  def render(%{live_action: :edit} = assigns) do
+    ~H"""
+    <div class="mx-auto max-w-sm">
+      <.header class="text-center">Confirm Account</.header>
+
+      <.simple_form for={@form} id="confirmation_form" phx-submit="confirm_account">
+        <input type="hidden" name={@form[:token].name} value={@form[:token].value} />
+        <:actions>
+          <.button phx-disable-with="Confirming..." class="w-full">Confirm my account</.button>
+        </:actions>
+      </.simple_form>
+
+      <p class="text-center mt-4">
+        <.link href={~p"/users/register"}>Register</.link>
+        | <.link href={~p"/users/log_in"}>Log in</.link>
+      </p>
+    </div>
+    """
+  end
+
+  def mount(%{"token" => token}, _session, socket) do
+    form = to_form(%{"token" => token}, as: "user")
+    {:ok, assign(socket, form: form), temporary_assigns: [form: nil]}
+  end
+
+  # Do not log in the user after confirmation to avoid a
+  # leaked token giving the user access to the account.
+  def handle_event("confirm_account", %{"user" => %{"token" => token}}, socket) do
+    case Accounts.confirm_user(token) do
+      {:ok, _} ->
+        {:noreply,
+         socket
+         |> put_flash(:info, "User confirmed successfully.")
+         |> redirect(to: ~p"/")}
+
+      :error ->
+        # If there is a current user and the account was already confirmed,
+        # then odds are that the confirmation link was already visited, either
+        # by some automation or by the user themselves, so we redirect without
+        # a warning message.
+        case socket.assigns do
+          %{current_user: %{confirmed_at: confirmed_at}} when not is_nil(confirmed_at) ->
+            {:noreply, redirect(socket, to: ~p"/")}
+
+          %{} ->
+            {:noreply,
+             socket
+             |> put_flash(:error, "User confirmation link is invalid or it has expired.")
+             |> redirect(to: ~p"/")}
+        end
+    end
+  end
+end

pento/lib/pento_web/live/user_forgot_password_live.ex

@@ -0,0 +1,50 @@
+defmodule PentoWeb.UserForgotPasswordLive do
+  use PentoWeb, :live_view
+
+  alias Pento.Accounts
+
+  def render(assigns) do
+    ~H"""
+    <div class="mx-auto max-w-sm">
+      <.header class="text-center">
+        Forgot your password?
+        <:subtitle>We'll send a password reset link to your inbox</:subtitle>
+      </.header>
+
+      <.simple_form for={@form} id="reset_password_form" phx-submit="send_email">
+        <.input field={@form[:email]} type="email" placeholder="Email" required />
+        <:actions>
+          <.button phx-disable-with="Sending..." class="w-full">
+            Send password reset instructions
+          </.button>
+        </:actions>
+      </.simple_form>
+      <p class="text-center text-sm mt-4">
+        <.link href={~p"/users/register"}>Register</.link>
+        | <.link href={~p"/users/log_in"}>Log in</.link>
+      </p>
+    </div>
+    """
+  end
+
+  def mount(_params, _session, socket) do
+    {:ok, assign(socket, form: to_form(%{}, as: "user"))}
+  end
+
+  def handle_event("send_email", %{"user" => %{"email" => email}}, socket) do
+    if user = Accounts.get_user_by_email(email) do
+      Accounts.deliver_user_reset_password_instructions(
+        user,
+        &url(~p"/users/reset_password/#{&1}")
+      )
+    end
+
+    info =
+      "If your email is in our system, you will receive instructions to reset your password shortly."
+
+    {:noreply,
+     socket
+     |> put_flash(:info, info)
+     |> redirect(to: ~p"/")}
+  end
+end

pento/lib/pento_web/live/user_login_live.ex

@@ -0,0 +1,43 @@
+defmodule PentoWeb.UserLoginLive do
+  use PentoWeb, :live_view
+
+  def render(assigns) do
+    ~H"""
+    <div class="mx-auto max-w-sm">
+      <.header class="text-center">
+        Log in to account
+        <:subtitle>
+          Don't have an account?
+          <.link navigate={~p"/users/register"} class="font-semibold text-brand hover:underline">
+            Sign up
+          </.link>
+          for an account now.
+        </:subtitle>
+      </.header>
+
+      <.simple_form for={@form} id="login_form" action={~p"/users/log_in"} phx-update="ignore">
+        <.input field={@form[:email]} type="email" label="Email" required />
+        <.input field={@form[:password]} type="password" label="Password" required />
+
+        <:actions>
+          <.input field={@form[:remember_me]} type="checkbox" label="Keep me logged in" />
+          <.link href={~p"/users/reset_password"} class="text-sm font-semibold">
+            Forgot your password?
+          </.link>
+        </:actions>
+        <:actions>
+          <.button phx-disable-with="Logging in..." class="w-full">
+            Log in <span aria-hidden="true">→</span>
+          </.button>
+        </:actions>
+      </.simple_form>
+    </div>
+    """
+  end
+
+  def mount(_params, _session, socket) do
+    email = Phoenix.Flash.get(socket.assigns.flash, :email)
+    form = to_form(%{"email" => email}, as: "user")
+    {:ok, assign(socket, form: form), temporary_assigns: [form: form]}
+  end
+end

pento/lib/pento_web/live/user_registration_live.ex

@@ -0,0 +1,87 @@
+defmodule PentoWeb.UserRegistrationLive do
+  use PentoWeb, :live_view
+
+  alias Pento.Accounts
+  alias Pento.Accounts.User
+
+  def render(assigns) do
+    ~H"""
+    <div class="mx-auto max-w-sm">
+      <.header class="text-center">
+        Register for an account
+        <:subtitle>
+          Already registered?
+          <.link navigate={~p"/users/log_in"} class="font-semibold text-brand hover:underline">
+            Log in
+          </.link>
+          to your account now.
+        </:subtitle>
+      </.header>
+
+      <.simple_form
+        for={@form}
+        id="registration_form"
+        phx-submit="save"
+        phx-change="validate"
+        phx-trigger-action={@trigger_submit}
+        action={~p"/users/log_in?_action=registered"}
+        method="post"
+      >
+        <.error :if={@check_errors}>
+          Oops, something went wrong! Please check the errors below.
+        </.error>
+
+        <.input field={@form[:email]} type="email" label="Email" required />
+        <.input field={@form[:password]} type="password" label="Password" required />
+
+        <:actions>
+          <.button phx-disable-with="Creating account..." class="w-full">Create an account</.button>
+        </:actions>
+      </.simple_form>
+    </div>
+    """
+  end
+
+  def mount(_params, _session, socket) do
+    changeset = Accounts.change_user_registration(%User{})
+
+    socket =
+      socket
+      |> assign(trigger_submit: false, check_errors: false)
+      |> assign_form(changeset)
+
+    {:ok, socket, temporary_assigns: [form: nil]}
+  end
+
+  def handle_event("save", %{"user" => user_params}, socket) do
+    case Accounts.register_user(user_params) do
+      {:ok, user} ->
+        {:ok, _} =
+          Accounts.deliver_user_confirmation_instructions(
+            user,
+            &url(~p"/users/confirm/#{&1}")
+          )
+
+        changeset = Accounts.change_user_registration(user)
+        {:noreply, socket |> assign(trigger_submit: true) |> assign_form(changeset)}
+
+      {:error, %Ecto.Changeset{} = changeset} ->
+        {:noreply, socket |> assign(check_errors: true) |> assign_form(changeset)}
+    end
+  end
+
+  def handle_event("validate", %{"user" => user_params}, socket) do
+    changeset = Accounts.change_user_registration(%User{}, user_params)
+    {:noreply, assign_form(socket, Map.put(changeset, :action, :validate))}
+  end
+
+  defp assign_form(socket, %Ecto.Changeset{} = changeset) do
+    form = to_form(changeset, as: "user")
+
+    if changeset.valid? do
+      assign(socket, form: form, check_errors: false)
+    else
+      assign(socket, form: form)
+    end
+  end
+end

pento/lib/pento_web/live/user_reset_password_live.ex

@@ -0,0 +1,89 @@
+defmodule PentoWeb.UserResetPasswordLive do
+  use PentoWeb, :live_view
+
+  alias Pento.Accounts
+
+  def render(assigns) do
+    ~H"""
+    <div class="mx-auto max-w-sm">
+      <.header class="text-center">Reset Password</.header>
+
+      <.simple_form
+        for={@form}
+        id="reset_password_form"
+        phx-submit="reset_password"
+        phx-change="validate"
+      >
+        <.error :if={@form.errors != []}>
+          Oops, something went wrong! Please check the errors below.
+        </.error>
+
+        <.input field={@form[:password]} type="password" label="New password" required />
+        <.input
+          field={@form[:password_confirmation]}
+          type="password"
+          label="Confirm new password"
+          required
+        />
+        <:actions>
+          <.button phx-disable-with="Resetting..." class="w-full">Reset Password</.button>
+        </:actions>
+      </.simple_form>
+
+      <p class="text-center text-sm mt-4">
+        <.link href={~p"/users/register"}>Register</.link>
+        | <.link href={~p"/users/log_in"}>Log in</.link>
+      </p>
+    </div>
+    """
+  end
+
+  def mount(params, _session, socket) do
+    socket = assign_user_and_token(socket, params)
+
+    form_source =
+      case socket.assigns do
+        %{user: user} ->
+          Accounts.change_user_password(user)
+
+        _ ->
+          %{}
+      end
+
+    {:ok, assign_form(socket, form_source), temporary_assigns: [form: nil]}
+  end
+
+  # Do not log in the user after reset password to avoid a
+  # leaked token giving the user access to the account.
+  def handle_event("reset_password", %{"user" => user_params}, socket) do
+    case Accounts.reset_user_password(socket.assigns.user, user_params) do
+      {:ok, _} ->
+        {:noreply,
+         socket
+         |> put_flash(:info, "Password reset successfully.")
+         |> redirect(to: ~p"/users/log_in")}
+
+      {:error, changeset} ->
+        {:noreply, assign_form(socket, Map.put(changeset, :action, :insert))}
+    end
+  end
+
+  def handle_event("validate", %{"user" => user_params}, socket) do
+    changeset = Accounts.change_user_password(socket.assigns.user, user_params)
+    {:noreply, assign_form(socket, Map.put(changeset, :action, :validate))}
+  end
+
+  defp assign_user_and_token(socket, %{"token" => token}) do
+    if user = Accounts.get_user_by_reset_password_token(token) do
+      assign(socket, user: user, token: token)
+    else
+      socket
+      |> put_flash(:error, "Reset password link is invalid or it has expired.")
+      |> redirect(to: ~p"/")
+    end
+  end
+
+  defp assign_form(socket, %{} = source) do
+    assign(socket, :form, to_form(source, as: "user"))
+  end
+end

pento/lib/pento_web/live/user_settings_live.ex

@@ -0,0 +1,167 @@
+defmodule PentoWeb.UserSettingsLive do
+  use PentoWeb, :live_view
+
+  alias Pento.Accounts
+
+  def render(assigns) do
+    ~H"""
+    <.header class="text-center">
+      Account Settings
+      <:subtitle>Manage your account email address and password settings</:subtitle>
+    </.header>
+
+    <div class="space-y-12 divide-y">
+      <div>
+        <.simple_form
+          for={@email_form}
+          id="email_form"
+          phx-submit="update_email"
+          phx-change="validate_email"
+        >
+          <.input field={@email_form[:email]} type="email" label="Email" required />
+          <.input
+            field={@email_form[:current_password]}
+            name="current_password"
+            id="current_password_for_email"
+            type="password"
+            label="Current password"
+            value={@email_form_current_password}
+            required
+          />
+          <:actions>
+            <.button phx-disable-with="Changing...">Change Email</.button>
+          </:actions>
+        </.simple_form>
+      </div>
+      <div>
+        <.simple_form
+          for={@password_form}
+          id="password_form"
+          action={~p"/users/log_in?_action=password_updated"}
+          method="post"
+          phx-change="validate_password"
+          phx-submit="update_password"
+          phx-trigger-action={@trigger_submit}
+        >
+          <input
+            name={@password_form[:email].name}
+            type="hidden"
+            id="hidden_user_email"
+            value={@current_email}
+          />
+          <.input field={@password_form[:password]} type="password" label="New password" required />
+          <.input
+            field={@password_form[:password_confirmation]}
+            type="password"
+            label="Confirm new password"
+          />
+          <.input
+            field={@password_form[:current_password]}
+            name="current_password"
+            type="password"
+            label="Current password"
+            id="current_password_for_password"
+            value={@current_password}
+            required
+          />
+          <:actions>
+            <.button phx-disable-with="Changing...">Change Password</.button>
+          </:actions>
+        </.simple_form>
+      </div>
+    </div>
+    """
+  end
+
+  def mount(%{"token" => token}, _session, socket) do
+    socket =
+      case Accounts.update_user_email(socket.assigns.current_user, token) do
+        :ok ->
+          put_flash(socket, :info, "Email changed successfully.")
+
+        :error ->
+          put_flash(socket, :error, "Email change link is invalid or it has expired.")
+      end
+
+    {:ok, push_navigate(socket, to: ~p"/users/settings")}
+  end
+
+  def mount(_params, _session, socket) do
+    user = socket.assigns.current_user
+    email_changeset = Accounts.change_user_email(user)
+    password_changeset = Accounts.change_user_password(user)
+
+    socket =
+      socket
+      |> assign(:current_password, nil)
+      |> assign(:email_form_current_password, nil)
+      |> assign(:current_email, user.email)
+      |> assign(:email_form, to_form(email_changeset))
+      |> assign(:password_form, to_form(password_changeset))
+      |> assign(:trigger_submit, false)
+
+    {:ok, socket}
+  end
+
+  def handle_event("validate_email", params, socket) do
+    %{"current_password" => password, "user" => user_params} = params
+
+    email_form =
+      socket.assigns.current_user
+      |> Accounts.change_user_email(user_params)
+      |> Map.put(:action, :validate)
+      |> to_form()
+
+    {:noreply, assign(socket, email_form: email_form, email_form_current_password: password)}
+  end
+
+  def handle_event("update_email", params, socket) do
+    %{"current_password" => password, "user" => user_params} = params
+    user = socket.assigns.current_user
+
+    case Accounts.apply_user_email(user, password, user_params) do
+      {:ok, applied_user} ->
+        Accounts.deliver_user_update_email_instructions(
+          applied_user,
+          user.email,
+          &url(~p"/users/settings/confirm_email/#{&1}")
+        )
+
+        info = "A link to confirm your email change has been sent to the new address."
+        {:noreply, socket |> put_flash(:info, info) |> assign(email_form_current_password: nil)}
+
+      {:error, changeset} ->
+        {:noreply, assign(socket, :email_form, to_form(Map.put(changeset, :action, :insert)))}
+    end
+  end
+
+  def handle_event("validate_password", params, socket) do
+    %{"current_password" => password, "user" => user_params} = params
+
+    password_form =
+      socket.assigns.current_user
+      |> Accounts.change_user_password(user_params)
+      |> Map.put(:action, :validate)
+      |> to_form()
+
+    {:noreply, assign(socket, password_form: password_form, current_password: password)}
+  end
+
+  def handle_event("update_password", params, socket) do
+    %{"current_password" => password, "user" => user_params} = params
+    user = socket.assigns.current_user
+
+    case Accounts.update_user_password(user, password, user_params) do
+      {:ok, user} ->
+        password_form =
+          user
+          |> Accounts.change_user_password(user_params)
+          |> to_form()
+
+        {:noreply, assign(socket, trigger_submit: true, password_form: password_form)}
+
+      {:error, changeset} ->
+        {:noreply, assign(socket, password_form: to_form(changeset))}
+    end
+  end
+end

pento/lib/pento_web/router.ex

@@ -1,6 +1,8 @@
 defmodule PentoWeb.Router do
   use PentoWeb, :router
 
+  import PentoWeb.UserAuth
+
   pipeline :browser do
     plug :accepts, ["html"]
     plug :fetch_session
@@ -8,6 +10,7 @@ defmodule PentoWeb.Router do
     plug :put_root_layout, html: {PentoWeb.Layouts, :root}
     plug :protect_from_forgery
     plug :put_secure_browser_headers
+    plug :fetch_current_user
   end
 
   pipeline :api do
@@ -42,4 +45,42 @@ defmodule PentoWeb.Router do
       forward "/mailbox", Plug.Swoosh.MailboxPreview
     end
   end
+
+  ## Authentication routes
+
+  scope "/", PentoWeb do
+    pipe_through [:browser, :redirect_if_user_is_authenticated]
+
+    live_session :redirect_if_user_is_authenticated,
+      on_mount: [{PentoWeb.UserAuth, :redirect_if_user_is_authenticated}] do
+      live "/users/register", UserRegistrationLive, :new
+      live "/users/log_in", UserLoginLive, :new
+      live "/users/reset_password", UserForgotPasswordLive, :new
+      live "/users/reset_password/:token", UserResetPasswordLive, :edit
+    end
+
+    post "/users/log_in", UserSessionController, :create
+  end
+
+  scope "/", PentoWeb do
+    pipe_through [:browser, :require_authenticated_user]
+
+    live_session :require_authenticated_user,
+      on_mount: [{PentoWeb.UserAuth, :ensure_authenticated}] do
+      live "/users/settings", UserSettingsLive, :edit
+      live "/users/settings/confirm_email/:token", UserSettingsLive, :confirm_email
+    end
+  end
+
+  scope "/", PentoWeb do
+    pipe_through [:browser]
+
+    delete "/users/log_out", UserSessionController, :delete
+
+    live_session :current_user,
+      on_mount: [{PentoWeb.UserAuth, :mount_current_user}] do
+      live "/users/confirm/:token", UserConfirmationLive, :edit
+      live "/users/confirm", UserConfirmationInstructionsLive, :new
+    end
+  end
 end

pento/lib/pento_web/user_auth.ex

@@ -0,0 +1,229 @@
+defmodule PentoWeb.UserAuth do
+  use PentoWeb, :verified_routes
+
+  import Plug.Conn
+  import Phoenix.Controller
+
+  alias Pento.Accounts
+
+  # Make the remember me cookie valid for 60 days.
+  # If you want bump or reduce this value, also change
+  # the token expiry itself in UserToken.
+  @max_age 60 * 60 * 24 * 60
+  @remember_me_cookie "_pento_web_user_remember_me"
+  @remember_me_options [sign: true, max_age: @max_age, same_site: "Lax"]
+
+  @doc """
+  Logs the user in.
+
+  It renews the session ID and clears the whole session
+  to avoid fixation attacks. See the renew_session
+  function to customize this behaviour.
+
+  It also sets a `:live_socket_id` key in the session,
+  so LiveView sessions are identified and automatically
+  disconnected on log out. The line can be safely removed
+  if you are not using LiveView.
+  """
+  def log_in_user(conn, user, params \\ %{}) do
+    token = Accounts.generate_user_session_token(user)
+    user_return_to = get_session(conn, :user_return_to)
+
+    conn
+    |> renew_session()
+    |> put_token_in_session(token)
+    |> maybe_write_remember_me_cookie(token, params)
+    |> redirect(to: user_return_to || signed_in_path(conn))
+  end
+
+  defp maybe_write_remember_me_cookie(conn, token, %{"remember_me" => "true"}) do
+    put_resp_cookie(conn, @remember_me_cookie, token, @remember_me_options)
+  end
+
+  defp maybe_write_remember_me_cookie(conn, _token, _params) do
+    conn
+  end
+
+  # This function renews the session ID and erases the whole
+  # session to avoid fixation attacks. If there is any data
+  # in the session you may want to preserve after log in/log out,
+  # you must explicitly fetch the session data before clearing
+  # and then immediately set it after clearing, for example:
+  #
+  #     defp renew_session(conn) do
+  #       preferred_locale = get_session(conn, :preferred_locale)
+  #
+  #       conn
+  #       |> configure_session(renew: true)
+  #       |> clear_session()
+  #       |> put_session(:preferred_locale, preferred_locale)
+  #     end
+  #
+  defp renew_session(conn) do
+    delete_csrf_token()
+
+    conn
+    |> configure_session(renew: true)
+    |> clear_session()
+  end
+
+  @doc """
+  Logs the user out.
+
+  It clears all session data for safety. See renew_session.
+  """
+  def log_out_user(conn) do
+    user_token = get_session(conn, :user_token)
+    user_token && Accounts.delete_user_session_token(user_token)
+
+    if live_socket_id = get_session(conn, :live_socket_id) do
+      PentoWeb.Endpoint.broadcast(live_socket_id, "disconnect", %{})
+    end
+
+    conn
+    |> renew_session()
+    |> delete_resp_cookie(@remember_me_cookie)
+    |> redirect(to: ~p"/")
+  end
+
+  @doc """
+  Authenticates the user by looking into the session
+  and remember me token.
+  """
+  def fetch_current_user(conn, _opts) do
+    {user_token, conn} = ensure_user_token(conn)
+    user = user_token && Accounts.get_user_by_session_token(user_token)
+    assign(conn, :current_user, user)
+  end
+
+  defp ensure_user_token(conn) do
+    if token = get_session(conn, :user_token) do
+      {token, conn}
+    else
+      conn = fetch_cookies(conn, signed: [@remember_me_cookie])
+
+      if token = conn.cookies[@remember_me_cookie] do
+        {token, put_token_in_session(conn, token)}
+      else
+        {nil, conn}
+      end
+    end
+  end
+
+  @doc """
+  Handles mounting and authenticating the current_user in LiveViews.
+
+  ## `on_mount` arguments
+
+    * `:mount_current_user` - Assigns current_user
+      to socket assigns based on user_token, or nil if
+      there's no user_token or no matching user.
+
+    * `:ensure_authenticated` - Authenticates the user from the session,
+      and assigns the current_user to socket assigns based
+      on user_token.
+      Redirects to login page if there's no logged user.
+
+    * `:redirect_if_user_is_authenticated` - Authenticates the user from the session.
+      Redirects to signed_in_path if there's a logged user.
+
+  ## Examples
+
+  Use the `on_mount` lifecycle macro in LiveViews to mount or authenticate
+  the current_user:
+
+      defmodule PentoWeb.PageLive do
+        use PentoWeb, :live_view
+
+        on_mount {PentoWeb.UserAuth, :mount_current_user}
+        ...
+      end
+
+  Or use the `live_session` of your router to invoke the on_mount callback:
+
+      live_session :authenticated, on_mount: [{PentoWeb.UserAuth, :ensure_authenticated}] do
+        live "/profile", ProfileLive, :index
+      end
+  """
+  def on_mount(:mount_current_user, _params, session, socket) do
+    {:cont, mount_current_user(socket, session)}
+  end
+
+  def on_mount(:ensure_authenticated, _params, session, socket) do
+    socket = mount_current_user(socket, session)
+
+    if socket.assigns.current_user do
+      {:cont, socket}
+    else
+      socket =
+        socket
+        |> Phoenix.LiveView.put_flash(:error, "You must log in to access this page.")
+        |> Phoenix.LiveView.redirect(to: ~p"/users/log_in")
+
+      {:halt, socket}
+    end
+  end
+
+  def on_mount(:redirect_if_user_is_authenticated, _params, session, socket) do
+    socket = mount_current_user(socket, session)
+
+    if socket.assigns.current_user do
+      {:halt, Phoenix.LiveView.redirect(socket, to: signed_in_path(socket))}
+    else
+      {:cont, socket}
+    end
+  end
+
+  defp mount_current_user(socket, session) do
+    Phoenix.Component.assign_new(socket, :current_user, fn ->
+      if user_token = session["user_token"] do
+        Accounts.get_user_by_session_token(user_token)
+      end
+    end)
+  end
+
+  @doc """
+  Used for routes that require the user to not be authenticated.
+  """
+  def redirect_if_user_is_authenticated(conn, _opts) do
+    if conn.assigns[:current_user] do
+      conn
+      |> redirect(to: signed_in_path(conn))
+      |> halt()
+    else
+      conn
+    end
+  end
+
+  @doc """
+  Used for routes that require the user to be authenticated.
+
+  If you want to enforce the user email is confirmed before
+  they use the application at all, here would be a good place.
+  """
+  def require_authenticated_user(conn, _opts) do
+    if conn.assigns[:current_user] do
+      conn
+    else
+      conn
+      |> put_flash(:error, "You must log in to access this page.")
+      |> maybe_store_return_to()
+      |> redirect(to: ~p"/users/log_in")
+      |> halt()
+    end
+  end
+
+  defp put_token_in_session(conn, token) do
+    conn
+    |> put_session(:user_token, token)
+    |> put_session(:live_socket_id, "users_sessions:#{Base.url_encode64(token)}")
+  end
+
+  defp maybe_store_return_to(%{method: "GET"} = conn) do
+    put_session(conn, :user_return_to, current_path(conn))
+  end
+
+  defp maybe_store_return_to(conn), do: conn
+
+  defp signed_in_path(_conn), do: ~p"/"
+end

pento/mix.exs

@@ -32,6 +32,7 @@ defmodule Pento.MixProject do
   # Type `mix help deps` for examples and options.
   defp deps do
     [
+      {:bcrypt_elixir, "~> 3.0"},
       {:phoenix, "~> 1.7.14"},
       {:phoenix_ecto, "~> 4.5"},
       {:ecto_sql, "~> 3.10"},

pento/mix.lock

@@ -1,11 +1,14 @@
 %{
   "bandit": {:hex, :bandit, "1.5.7", "6856b1e1df4f2b0cb3df1377eab7891bec2da6a7fd69dc78594ad3e152363a50", [:mix], [{:hpax, "~> 1.0.0", [hex: :hpax, repo: "hexpm", optional: false]}, {:plug, "~> 1.14", [hex: :plug, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}, {:thousand_island, "~> 1.0", [hex: :thousand_island, repo: "hexpm", optional: false]}, {:websock, "~> 0.5", [hex: :websock, repo: "hexpm", optional: false]}], "hexpm", "f2dd92ae87d2cbea2fa9aa1652db157b6cba6c405cb44d4f6dd87abba41371cd"},
+  "bcrypt_elixir": {:hex, :bcrypt_elixir, "3.1.0", "0b110a9a6c619b19a7f73fa3004aa11d6e719a67e672d1633dc36b6b2290a0f7", [:make, :mix], [{:comeonin, "~> 5.3", [hex: :comeonin, repo: "hexpm", optional: false]}, {:elixir_make, "~> 0.6", [hex: :elixir_make, repo: "hexpm", optional: false]}], "hexpm", "2ad2acb5a8bc049e8d5aa267802631912bb80d5f4110a178ae7999e69dca1bf7"},
   "castore": {:hex, :castore, "1.0.8", "dedcf20ea746694647f883590b82d9e96014057aff1d44d03ec90f36a5c0dc6e", [:mix], [], "hexpm", "0b2b66d2ee742cb1d9cb8c8be3b43c3a70ee8651f37b75a8b982e036752983f1"},
+  "comeonin": {:hex, :comeonin, "5.4.0", "246a56ca3f41d404380fc6465650ddaa532c7f98be4bda1b4656b3a37cc13abe", [:mix], [], "hexpm", "796393a9e50d01999d56b7b8420ab0481a7538d0caf80919da493b4a6e51faf1"},
   "db_connection": {:hex, :db_connection, "2.7.0", "b99faa9291bb09892c7da373bb82cba59aefa9b36300f6145c5f201c7adf48ec", [:mix], [{:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "dcf08f31b2701f857dfc787fbad78223d61a32204f217f15e881dd93e4bdd3ff"},
   "decimal": {:hex, :decimal, "2.1.1", "5611dca5d4b2c3dd497dec8f68751f1f1a54755e8ed2a966c2633cf885973ad6", [:mix], [], "hexpm", "53cfe5f497ed0e7771ae1a475575603d77425099ba5faef9394932b35020ffcc"},
   "dns_cluster": {:hex, :dns_cluster, "0.1.3", "0bc20a2c88ed6cc494f2964075c359f8c2d00e1bf25518a6a6c7fd277c9b0c66", [:mix], [], "hexpm", "46cb7c4a1b3e52c7ad4cbe33ca5079fbde4840dedeafca2baf77996c2da1bc33"},
   "ecto": {:hex, :ecto, "3.12.1", "626765f7066589de6fa09e0876a253ff60c3d00870dd3a1cd696e2ba67bfceea", [:mix], [{:decimal, "~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "df0045ab9d87be947228e05a8d153f3e06e0d05ab10c3b3cc557d2f7243d1940"},
   "ecto_sql": {:hex, :ecto_sql, "3.12.0", "73cea17edfa54bde76ee8561b30d29ea08f630959685006d9c6e7d1e59113b7d", [:mix], [{:db_connection, "~> 2.4.1 or ~> 2.5", [hex: :db_connection, repo: "hexpm", optional: false]}, {:ecto, "~> 3.12", [hex: :ecto, repo: "hexpm", optional: false]}, {:myxql, "~> 0.7", [hex: :myxql, repo: "hexpm", optional: true]}, {:postgrex, "~> 0.19 or ~> 1.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:tds, "~> 2.1.1 or ~> 2.2", [hex: :tds, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4.0 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "dc9e4d206f274f3947e96142a8fdc5f69a2a6a9abb4649ef5c882323b6d512f0"},
+  "elixir_make": {:hex, :elixir_make, "0.8.4", "4960a03ce79081dee8fe119d80ad372c4e7badb84c493cc75983f9d3bc8bde0f", [:mix], [{:castore, "~> 0.1 or ~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:certifi, "~> 2.0", [hex: :certifi, repo: "hexpm", optional: true]}], "hexpm", "6e7f1d619b5f61dfabd0a20aa268e575572b542ac31723293a4c1a567d5ef040"},
   "esbuild": {:hex, :esbuild, "0.8.1", "0cbf919f0eccb136d2eeef0df49c4acf55336de864e63594adcea3814f3edf41", [:mix], [{:castore, ">= 0.0.0", [hex: :castore, repo: "hexpm", optional: false]}, {:jason, "~> 1.4", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "25fc876a67c13cb0a776e7b5d7974851556baeda2085296c14ab48555ea7560f"},
   "expo": {:hex, :expo, "1.0.0", "647639267e088717232f4d4451526e7a9de31a3402af7fcbda09b27e9a10395a", [:mix], [], "hexpm", "18d2093d344d97678e8a331ca0391e85d29816f9664a25653fd7e6166827827c"},
   "file_system": {:hex, :file_system, "1.0.0", "b689cc7dcee665f774de94b5a832e578bd7963c8e637ef940cd44327db7de2cd", [:mix], [], "hexpm", "6752092d66aec5a10e662aefeed8ddb9531d79db0bc145bb8c40325ca1d8536d"},

pento/priv/repo/migrations/20240816145518_create_users_auth_tables.exs

@@ -0,0 +1,29 @@
+defmodule Pento.Repo.Migrations.CreateUsersAuthTables do
+  use Ecto.Migration
+
+  def change do
+    execute "CREATE EXTENSION IF NOT EXISTS citext", ""
+
+    create table(:users) do
+      add :email, :citext, null: false
+      add :hashed_password, :string, null: false
+      add :confirmed_at, :utc_datetime
+
+      timestamps(type: :utc_datetime)
+    end
+
+    create unique_index(:users, [:email])
+
+    create table(:users_tokens) do
+      add :user_id, references(:users, on_delete: :delete_all), null: false
+      add :token, :binary, null: false
+      add :context, :string, null: false
+      add :sent_to, :string
+
+      timestamps(type: :utc_datetime, updated_at: false)
+    end
+
+    create index(:users_tokens, [:user_id])
+    create unique_index(:users_tokens, [:context, :token])
+  end
+end

pento/test/pento/accounts_test.exs

@@ -0,0 +1,508 @@
+defmodule Pento.AccountsTest do
+  use Pento.DataCase
+
+  alias Pento.Accounts
+
+  import Pento.AccountsFixtures
+  alias Pento.Accounts.{User, UserToken}
+
+  describe "get_user_by_email/1" do
+    test "does not return the user if the email does not exist" do
+      refute Accounts.get_user_by_email("unknown@example.com")
+    end
+
+    test "returns the user if the email exists" do
+      %{id: id} = user = user_fixture()
+      assert %User{id: ^id} = Accounts.get_user_by_email(user.email)
+    end
+  end
+
+  describe "get_user_by_email_and_password/2" do
+    test "does not return the user if the email does not exist" do
+      refute Accounts.get_user_by_email_and_password("unknown@example.com", "hello world!")
+    end
+
+    test "does not return the user if the password is not valid" do
+      user = user_fixture()
+      refute Accounts.get_user_by_email_and_password(user.email, "invalid")
+    end
+
+    test "returns the user if the email and password are valid" do
+      %{id: id} = user = user_fixture()
+
+      assert %User{id: ^id} =
+               Accounts.get_user_by_email_and_password(user.email, valid_user_password())
+    end
+  end
+
+  describe "get_user!/1" do
+    test "raises if id is invalid" do
+      assert_raise Ecto.NoResultsError, fn ->
+        Accounts.get_user!(-1)
+      end
+    end
+
+    test "returns the user with the given id" do
+      %{id: id} = user = user_fixture()
+      assert %User{id: ^id} = Accounts.get_user!(user.id)
+    end
+  end
+
+  describe "register_user/1" do
+    test "requires email and password to be set" do
+      {:error, changeset} = Accounts.register_user(%{})
+
+      assert %{
+               password: ["can't be blank"],
+               email: ["can't be blank"]
+             } = errors_on(changeset)
+    end
+
+    test "validates email and password when given" do
+      {:error, changeset} = Accounts.register_user(%{email: "not valid", password: "not valid"})
+
+      assert %{
+               email: ["must have the @ sign and no spaces"],
+               password: ["should be at least 12 character(s)"]
+             } = errors_on(changeset)
+    end
+
+    test "validates maximum values for email and password for security" do
+      too_long = String.duplicate("db", 100)
+      {:error, changeset} = Accounts.register_user(%{email: too_long, password: too_long})
+      assert "should be at most 160 character(s)" in errors_on(changeset).email
+      assert "should be at most 72 character(s)" in errors_on(changeset).password
+    end
+
+    test "validates email uniqueness" do
+      %{email: email} = user_fixture()
+      {:error, changeset} = Accounts.register_user(%{email: email})
+      assert "has already been taken" in errors_on(changeset).email
+
+      # Now try with the upper cased email too, to check that email case is ignored.
+      {:error, changeset} = Accounts.register_user(%{email: String.upcase(email)})
+      assert "has already been taken" in errors_on(changeset).email
+    end
+
+    test "registers users with a hashed password" do
+      email = unique_user_email()
+      {:ok, user} = Accounts.register_user(valid_user_attributes(email: email))
+      assert user.email == email
+      assert is_binary(user.hashed_password)
+      assert is_nil(user.confirmed_at)
+      assert is_nil(user.password)
+    end
+  end
+
+  describe "change_user_registration/2" do
+    test "returns a changeset" do
+      assert %Ecto.Changeset{} = changeset = Accounts.change_user_registration(%User{})
+      assert changeset.required == [:password, :email]
+    end
+
+    test "allows fields to be set" do
+      email = unique_user_email()
+      password = valid_user_password()
+
+      changeset =
+        Accounts.change_user_registration(
+          %User{},
+          valid_user_attributes(email: email, password: password)
+        )
+
+      assert changeset.valid?
+      assert get_change(changeset, :email) == email
+      assert get_change(changeset, :password) == password
+      assert is_nil(get_change(changeset, :hashed_password))
+    end
+  end
+
+  describe "change_user_email/2" do
+    test "returns a user changeset" do
+      assert %Ecto.Changeset{} = changeset = Accounts.change_user_email(%User{})
+      assert changeset.required == [:email]
+    end
+  end
+
+  describe "apply_user_email/3" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "requires email to change", %{user: user} do
+      {:error, changeset} = Accounts.apply_user_email(user, valid_user_password(), %{})
+      assert %{email: ["did not change"]} = errors_on(changeset)
+    end
+
+    test "validates email", %{user: user} do
+      {:error, changeset} =
+        Accounts.apply_user_email(user, valid_user_password(), %{email: "not valid"})
+
+      assert %{email: ["must have the @ sign and no spaces"]} = errors_on(changeset)
+    end
+
+    test "validates maximum value for email for security", %{user: user} do
+      too_long = String.duplicate("db", 100)
+
+      {:error, changeset} =
+        Accounts.apply_user_email(user, valid_user_password(), %{email: too_long})
+
+      assert "should be at most 160 character(s)" in errors_on(changeset).email
+    end
+
+    test "validates email uniqueness", %{user: user} do
+      %{email: email} = user_fixture()
+      password = valid_user_password()
+
+      {:error, changeset} = Accounts.apply_user_email(user, password, %{email: email})
+
+      assert "has already been taken" in errors_on(changeset).email
+    end
+
+    test "validates current password", %{user: user} do
+      {:error, changeset} =
+        Accounts.apply_user_email(user, "invalid", %{email: unique_user_email()})
+
+      assert %{current_password: ["is not valid"]} = errors_on(changeset)
+    end
+
+    test "applies the email without persisting it", %{user: user} do
+      email = unique_user_email()
+      {:ok, user} = Accounts.apply_user_email(user, valid_user_password(), %{email: email})
+      assert user.email == email
+      assert Accounts.get_user!(user.id).email != email
+    end
+  end
+
+  describe "deliver_user_update_email_instructions/3" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "sends token through notification", %{user: user} do
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_user_update_email_instructions(user, "current@example.com", url)
+        end)
+
+      {:ok, token} = Base.url_decode64(token, padding: false)
+      assert user_token = Repo.get_by(UserToken, token: :crypto.hash(:sha256, token))
+      assert user_token.user_id == user.id
+      assert user_token.sent_to == user.email
+      assert user_token.context == "change:current@example.com"
+    end
+  end
+
+  describe "update_user_email/2" do
+    setup do
+      user = user_fixture()
+      email = unique_user_email()
+
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_user_update_email_instructions(%{user | email: email}, user.email, url)
+        end)
+
+      %{user: user, token: token, email: email}
+    end
+
+    test "updates the email with a valid token", %{user: user, token: token, email: email} do
+      assert Accounts.update_user_email(user, token) == :ok
+      changed_user = Repo.get!(User, user.id)
+      assert changed_user.email != user.email
+      assert changed_user.email == email
+      assert changed_user.confirmed_at
+      assert changed_user.confirmed_at != user.confirmed_at
+      refute Repo.get_by(UserToken, user_id: user.id)
+    end
+
+    test "does not update email with invalid token", %{user: user} do
+      assert Accounts.update_user_email(user, "oops") == :error
+      assert Repo.get!(User, user.id).email == user.email
+      assert Repo.get_by(UserToken, user_id: user.id)
+    end
+
+    test "does not update email if user email changed", %{user: user, token: token} do
+      assert Accounts.update_user_email(%{user | email: "current@example.com"}, token) == :error
+      assert Repo.get!(User, user.id).email == user.email
+      assert Repo.get_by(UserToken, user_id: user.id)
+    end
+
+    test "does not update email if token expired", %{user: user, token: token} do
+      {1, nil} = Repo.update_all(UserToken, set: [inserted_at: ~N[2020-01-01 00:00:00]])
+      assert Accounts.update_user_email(user, token) == :error
+      assert Repo.get!(User, user.id).email == user.email
+      assert Repo.get_by(UserToken, user_id: user.id)
+    end
+  end
+
+  describe "change_user_password/2" do
+    test "returns a user changeset" do
+      assert %Ecto.Changeset{} = changeset = Accounts.change_user_password(%User{})
+      assert changeset.required == [:password]
+    end
+
+    test "allows fields to be set" do
+      changeset =
+        Accounts.change_user_password(%User{}, %{
+          "password" => "new valid password"
+        })
+
+      assert changeset.valid?
+      assert get_change(changeset, :password) == "new valid password"
+      assert is_nil(get_change(changeset, :hashed_password))
+    end
+  end
+
+  describe "update_user_password/3" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "validates password", %{user: user} do
+      {:error, changeset} =
+        Accounts.update_user_password(user, valid_user_password(), %{
+          password: "not valid",
+          password_confirmation: "another"
+        })
+
+      assert %{
+               password: ["should be at least 12 character(s)"],
+               password_confirmation: ["does not match password"]
+             } = errors_on(changeset)
+    end
+
+    test "validates maximum values for password for security", %{user: user} do
+      too_long = String.duplicate("db", 100)
+
+      {:error, changeset} =
+        Accounts.update_user_password(user, valid_user_password(), %{password: too_long})
+
+      assert "should be at most 72 character(s)" in errors_on(changeset).password
+    end
+
+    test "validates current password", %{user: user} do
+      {:error, changeset} =
+        Accounts.update_user_password(user, "invalid", %{password: valid_user_password()})
+
+      assert %{current_password: ["is not valid"]} = errors_on(changeset)
+    end
+
+    test "updates the password", %{user: user} do
+      {:ok, user} =
+        Accounts.update_user_password(user, valid_user_password(), %{
+          password: "new valid password"
+        })
+
+      assert is_nil(user.password)
+      assert Accounts.get_user_by_email_and_password(user.email, "new valid password")
+    end
+
+    test "deletes all tokens for the given user", %{user: user} do
+      _ = Accounts.generate_user_session_token(user)
+
+      {:ok, _} =
+        Accounts.update_user_password(user, valid_user_password(), %{
+          password: "new valid password"
+        })
+
+      refute Repo.get_by(UserToken, user_id: user.id)
+    end
+  end
+
+  describe "generate_user_session_token/1" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "generates a token", %{user: user} do
+      token = Accounts.generate_user_session_token(user)
+      assert user_token = Repo.get_by(UserToken, token: token)
+      assert user_token.context == "session"
+
+      # Creating the same token for another user should fail
+      assert_raise Ecto.ConstraintError, fn ->
+        Repo.insert!(%UserToken{
+          token: user_token.token,
+          user_id: user_fixture().id,
+          context: "session"
+        })
+      end
+    end
+  end
+
+  describe "get_user_by_session_token/1" do
+    setup do
+      user = user_fixture()
+      token = Accounts.generate_user_session_token(user)
+      %{user: user, token: token}
+    end
+
+    test "returns user by token", %{user: user, token: token} do
+      assert session_user = Accounts.get_user_by_session_token(token)
+      assert session_user.id == user.id
+    end
+
+    test "does not return user for invalid token" do
+      refute Accounts.get_user_by_session_token("oops")
+    end
+
+    test "does not return user for expired token", %{token: token} do
+      {1, nil} = Repo.update_all(UserToken, set: [inserted_at: ~N[2020-01-01 00:00:00]])
+      refute Accounts.get_user_by_session_token(token)
+    end
+  end
+
+  describe "delete_user_session_token/1" do
+    test "deletes the token" do
+      user = user_fixture()
+      token = Accounts.generate_user_session_token(user)
+      assert Accounts.delete_user_session_token(token) == :ok
+      refute Accounts.get_user_by_session_token(token)
+    end
+  end
+
+  describe "deliver_user_confirmation_instructions/2" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "sends token through notification", %{user: user} do
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_user_confirmation_instructions(user, url)
+        end)
+
+      {:ok, token} = Base.url_decode64(token, padding: false)
+      assert user_token = Repo.get_by(UserToken, token: :crypto.hash(:sha256, token))
+      assert user_token.user_id == user.id
+      assert user_token.sent_to == user.email
+      assert user_token.context == "confirm"
+    end
+  end
+
+  describe "confirm_user/1" do
+    setup do
+      user = user_fixture()
+
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_user_confirmation_instructions(user, url)
+        end)
+
+      %{user: user, token: token}
+    end
+
+    test "confirms the email with a valid token", %{user: user, token: token} do
+      assert {:ok, confirmed_user} = Accounts.confirm_user(token)
+      assert confirmed_user.confirmed_at
+      assert confirmed_user.confirmed_at != user.confirmed_at
+      assert Repo.get!(User, user.id).confirmed_at
+      refute Repo.get_by(UserToken, user_id: user.id)
+    end
+
+    test "does not confirm with invalid token", %{user: user} do
+      assert Accounts.confirm_user("oops") == :error
+      refute Repo.get!(User, user.id).confirmed_at
+      assert Repo.get_by(UserToken, user_id: user.id)
+    end
+
+    test "does not confirm email if token expired", %{user: user, token: token} do
+      {1, nil} = Repo.update_all(UserToken, set: [inserted_at: ~N[2020-01-01 00:00:00]])
+      assert Accounts.confirm_user(token) == :error
+      refute Repo.get!(User, user.id).confirmed_at
+      assert Repo.get_by(UserToken, user_id: user.id)
+    end
+  end
+
+  describe "deliver_user_reset_password_instructions/2" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "sends token through notification", %{user: user} do
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_user_reset_password_instructions(user, url)
+        end)
+
+      {:ok, token} = Base.url_decode64(token, padding: false)
+      assert user_token = Repo.get_by(UserToken, token: :crypto.hash(:sha256, token))
+      assert user_token.user_id == user.id
+      assert user_token.sent_to == user.email
+      assert user_token.context == "reset_password"
+    end
+  end
+
+  describe "get_user_by_reset_password_token/1" do
+    setup do
+      user = user_fixture()
+
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_user_reset_password_instructions(user, url)
+        end)
+
+      %{user: user, token: token}
+    end
+
+    test "returns the user with valid token", %{user: %{id: id}, token: token} do
+      assert %User{id: ^id} = Accounts.get_user_by_reset_password_token(token)
+      assert Repo.get_by(UserToken, user_id: id)
+    end
+
+    test "does not return the user with invalid token", %{user: user} do
+      refute Accounts.get_user_by_reset_password_token("oops")
+      assert Repo.get_by(UserToken, user_id: user.id)
+    end
+
+    test "does not return the user if token expired", %{user: user, token: token} do
+      {1, nil} = Repo.update_all(UserToken, set: [inserted_at: ~N[2020-01-01 00:00:00]])
+      refute Accounts.get_user_by_reset_password_token(token)
+      assert Repo.get_by(UserToken, user_id: user.id)
+    end
+  end
+
+  describe "reset_user_password/2" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "validates password", %{user: user} do
+      {:error, changeset} =
+        Accounts.reset_user_password(user, %{
+          password: "not valid",
+          password_confirmation: "another"
+        })
+
+      assert %{
+               password: ["should be at least 12 character(s)"],
+               password_confirmation: ["does not match password"]
+             } = errors_on(changeset)
+    end
+
+    test "validates maximum values for password for security", %{user: user} do
+      too_long = String.duplicate("db", 100)
+      {:error, changeset} = Accounts.reset_user_password(user, %{password: too_long})
+      assert "should be at most 72 character(s)" in errors_on(changeset).password
+    end
+
+    test "updates the password", %{user: user} do
+      {:ok, updated_user} = Accounts.reset_user_password(user, %{password: "new valid password"})
+      assert is_nil(updated_user.password)
+      assert Accounts.get_user_by_email_and_password(user.email, "new valid password")
+    end
+
+    test "deletes all tokens for the given user", %{user: user} do
+      _ = Accounts.generate_user_session_token(user)
+      {:ok, _} = Accounts.reset_user_password(user, %{password: "new valid password"})
+      refute Repo.get_by(UserToken, user_id: user.id)
+    end
+  end
+
+  describe "inspect/2 for the User module" do
+    test "does not include password" do
+      refute inspect(%User{password: "123456"}) =~ "password: \"123456\""
+    end
+  end
+end

pento/test/pento_web/controllers/user_session_controller_test.exs

@@ -0,0 +1,113 @@
+defmodule PentoWeb.UserSessionControllerTest do
+  use PentoWeb.ConnCase, async: true
+
+  import Pento.AccountsFixtures
+
+  setup do
+    %{user: user_fixture()}
+  end
+
+  describe "POST /users/log_in" do
+    test "logs the user in", %{conn: conn, user: user} do
+      conn =
+        post(conn, ~p"/users/log_in", %{
+          "user" => %{"email" => user.email, "password" => valid_user_password()}
+        })
+
+      assert get_session(conn, :user_token)
+      assert redirected_to(conn) == ~p"/"
+
+      # Now do a logged in request and assert on the menu
+      conn = get(conn, ~p"/")
+      response = html_response(conn, 200)
+      assert response =~ user.email
+      assert response =~ ~p"/users/settings"
+      assert response =~ ~p"/users/log_out"
+    end
+
+    test "logs the user in with remember me", %{conn: conn, user: user} do
+      conn =
+        post(conn, ~p"/users/log_in", %{
+          "user" => %{
+            "email" => user.email,
+            "password" => valid_user_password(),
+            "remember_me" => "true"
+          }
+        })
+
+      assert conn.resp_cookies["_pento_web_user_remember_me"]
+      assert redirected_to(conn) == ~p"/"
+    end
+
+    test "logs the user in with return to", %{conn: conn, user: user} do
+      conn =
+        conn
+        |> init_test_session(user_return_to: "/foo/bar")
+        |> post(~p"/users/log_in", %{
+          "user" => %{
+            "email" => user.email,
+            "password" => valid_user_password()
+          }
+        })
+
+      assert redirected_to(conn) == "/foo/bar"
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "Welcome back!"
+    end
+
+    test "login following registration", %{conn: conn, user: user} do
+      conn =
+        conn
+        |> post(~p"/users/log_in", %{
+          "_action" => "registered",
+          "user" => %{
+            "email" => user.email,
+            "password" => valid_user_password()
+          }
+        })
+
+      assert redirected_to(conn) == ~p"/"
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "Account created successfully"
+    end
+
+    test "login following password update", %{conn: conn, user: user} do
+      conn =
+        conn
+        |> post(~p"/users/log_in", %{
+          "_action" => "password_updated",
+          "user" => %{
+            "email" => user.email,
+            "password" => valid_user_password()
+          }
+        })
+
+      assert redirected_to(conn) == ~p"/users/settings"
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "Password updated successfully"
+    end
+
+    test "redirects to login page with invalid credentials", %{conn: conn} do
+      conn =
+        post(conn, ~p"/users/log_in", %{
+          "user" => %{"email" => "invalid@email.com", "password" => "invalid_password"}
+        })
+
+      assert Phoenix.Flash.get(conn.assigns.flash, :error) == "Invalid email or password"
+      assert redirected_to(conn) == ~p"/users/log_in"
+    end
+  end
+
+  describe "DELETE /users/log_out" do
+    test "logs the user out", %{conn: conn, user: user} do
+      conn = conn |> log_in_user(user) |> delete(~p"/users/log_out")
+      assert redirected_to(conn) == ~p"/"
+      refute get_session(conn, :user_token)
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "Logged out successfully"
+    end
+
+    test "succeeds even if the user is not logged in", %{conn: conn} do
+      conn = delete(conn, ~p"/users/log_out")
+      assert redirected_to(conn) == ~p"/"
+      refute get_session(conn, :user_token)
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "Logged out successfully"
+    end
+  end
+end

pento/test/pento_web/live/user_confirmation_instructions_live_test.exs

@@ -0,0 +1,67 @@
+defmodule PentoWeb.UserConfirmationInstructionsLiveTest do
+  use PentoWeb.ConnCase, async: true
+
+  import Phoenix.LiveViewTest
+  import Pento.AccountsFixtures
+
+  alias Pento.Accounts
+  alias Pento.Repo
+
+  setup do
+    %{user: user_fixture()}
+  end
+
+  describe "Resend confirmation" do
+    test "renders the resend confirmation page", %{conn: conn} do
+      {:ok, _lv, html} = live(conn, ~p"/users/confirm")
+      assert html =~ "Resend confirmation instructions"
+    end
+
+    test "sends a new confirmation token", %{conn: conn, user: user} do
+      {:ok, lv, _html} = live(conn, ~p"/users/confirm")
+
+      {:ok, conn} =
+        lv
+        |> form("#resend_confirmation_form", user: %{email: user.email})
+        |> render_submit()
+        |> follow_redirect(conn, ~p"/")
+
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~
+               "If your email is in our system"
+
+      assert Repo.get_by!(Accounts.UserToken, user_id: user.id).context == "confirm"
+    end
+
+    test "does not send confirmation token if user is confirmed", %{conn: conn, user: user} do
+      Repo.update!(Accounts.User.confirm_changeset(user))
+
+      {:ok, lv, _html} = live(conn, ~p"/users/confirm")
+
+      {:ok, conn} =
+        lv
+        |> form("#resend_confirmation_form", user: %{email: user.email})
+        |> render_submit()
+        |> follow_redirect(conn, ~p"/")
+
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~
+               "If your email is in our system"
+
+      refute Repo.get_by(Accounts.UserToken, user_id: user.id)
+    end
+
+    test "does not send confirmation token if email is invalid", %{conn: conn} do
+      {:ok, lv, _html} = live(conn, ~p"/users/confirm")
+
+      {:ok, conn} =
+        lv
+        |> form("#resend_confirmation_form", user: %{email: "unknown@example.com"})
+        |> render_submit()
+        |> follow_redirect(conn, ~p"/")
+
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~
+               "If your email is in our system"
+
+      assert Repo.all(Accounts.UserToken) == []
+    end
+  end
+end

pento/test/pento_web/live/user_confirmation_live_test.exs

@@ -0,0 +1,89 @@
+defmodule PentoWeb.UserConfirmationLiveTest do
+  use PentoWeb.ConnCase, async: true
+
+  import Phoenix.LiveViewTest
+  import Pento.AccountsFixtures
+
+  alias Pento.Accounts
+  alias Pento.Repo
+
+  setup do
+    %{user: user_fixture()}
+  end
+
+  describe "Confirm user" do
+    test "renders confirmation page", %{conn: conn} do
+      {:ok, _lv, html} = live(conn, ~p"/users/confirm/some-token")
+      assert html =~ "Confirm Account"
+    end
+
+    test "confirms the given token once", %{conn: conn, user: user} do
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_user_confirmation_instructions(user, url)
+        end)
+
+      {:ok, lv, _html} = live(conn, ~p"/users/confirm/#{token}")
+
+      result =
+        lv
+        |> form("#confirmation_form")
+        |> render_submit()
+        |> follow_redirect(conn, "/")
+
+      assert {:ok, conn} = result
+
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~
+               "User confirmed successfully"
+
+      assert Accounts.get_user!(user.id).confirmed_at
+      refute get_session(conn, :user_token)
+      assert Repo.all(Accounts.UserToken) == []
+
+      # when not logged in
+      {:ok, lv, _html} = live(conn, ~p"/users/confirm/#{token}")
+
+      result =
+        lv
+        |> form("#confirmation_form")
+        |> render_submit()
+        |> follow_redirect(conn, "/")
+
+      assert {:ok, conn} = result
+
+      assert Phoenix.Flash.get(conn.assigns.flash, :error) =~
+               "User confirmation link is invalid or it has expired"
+
+      # when logged in
+      conn =
+        build_conn()
+        |> log_in_user(user)
+
+      {:ok, lv, _html} = live(conn, ~p"/users/confirm/#{token}")
+
+      result =
+        lv
+        |> form("#confirmation_form")
+        |> render_submit()
+        |> follow_redirect(conn, "/")
+
+      assert {:ok, conn} = result
+      refute Phoenix.Flash.get(conn.assigns.flash, :error)
+    end
+
+    test "does not confirm email with invalid token", %{conn: conn, user: user} do
+      {:ok, lv, _html} = live(conn, ~p"/users/confirm/invalid-token")
+
+      {:ok, conn} =
+        lv
+        |> form("#confirmation_form")
+        |> render_submit()
+        |> follow_redirect(conn, ~p"/")
+
+      assert Phoenix.Flash.get(conn.assigns.flash, :error) =~
+               "User confirmation link is invalid or it has expired"
+
+      refute Accounts.get_user!(user.id).confirmed_at
+    end
+  end
+end

pento/test/pento_web/live/user_forgot_password_live_test.exs

@@ -0,0 +1,63 @@
+defmodule PentoWeb.UserForgotPasswordLiveTest do
+  use PentoWeb.ConnCase, async: true
+
+  import Phoenix.LiveViewTest
+  import Pento.AccountsFixtures
+
+  alias Pento.Accounts
+  alias Pento.Repo
+
+  describe "Forgot password page" do
+    test "renders email page", %{conn: conn} do
+      {:ok, lv, html} = live(conn, ~p"/users/reset_password")
+
+      assert html =~ "Forgot your password?"
+      assert has_element?(lv, ~s|a[href="#{~p"/users/register"}"]|, "Register")
+      assert has_element?(lv, ~s|a[href="#{~p"/users/log_in"}"]|, "Log in")
+    end
+
+    test "redirects if already logged in", %{conn: conn} do
+      result =
+        conn
+        |> log_in_user(user_fixture())
+        |> live(~p"/users/reset_password")
+        |> follow_redirect(conn, ~p"/")
+
+      assert {:ok, _conn} = result
+    end
+  end
+
+  describe "Reset link" do
+    setup do
+      %{user: user_fixture()}
+    end
+
+    test "sends a new reset password token", %{conn: conn, user: user} do
+      {:ok, lv, _html} = live(conn, ~p"/users/reset_password")
+
+      {:ok, conn} =
+        lv
+        |> form("#reset_password_form", user: %{"email" => user.email})
+        |> render_submit()
+        |> follow_redirect(conn, "/")
+
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "If your email is in our system"
+
+      assert Repo.get_by!(Accounts.UserToken, user_id: user.id).context ==
+               "reset_password"
+    end
+
+    test "does not send reset password token if email is invalid", %{conn: conn} do
+      {:ok, lv, _html} = live(conn, ~p"/users/reset_password")
+
+      {:ok, conn} =
+        lv
+        |> form("#reset_password_form", user: %{"email" => "unknown@example.com"})
+        |> render_submit()
+        |> follow_redirect(conn, "/")
+
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "If your email is in our system"
+      assert Repo.all(Accounts.UserToken) == []
+    end
+  end
+end

pento/test/pento_web/live/user_login_live_test.exs

@@ -0,0 +1,87 @@
+defmodule PentoWeb.UserLoginLiveTest do
+  use PentoWeb.ConnCase, async: true
+
+  import Phoenix.LiveViewTest
+  import Pento.AccountsFixtures
+
+  describe "Log in page" do
+    test "renders log in page", %{conn: conn} do
+      {:ok, _lv, html} = live(conn, ~p"/users/log_in")
+
+      assert html =~ "Log in"
+      assert html =~ "Register"
+      assert html =~ "Forgot your password?"
+    end
+
+    test "redirects if already logged in", %{conn: conn} do
+      result =
+        conn
+        |> log_in_user(user_fixture())
+        |> live(~p"/users/log_in")
+        |> follow_redirect(conn, "/")
+
+      assert {:ok, _conn} = result
+    end
+  end
+
+  describe "user login" do
+    test "redirects if user login with valid credentials", %{conn: conn} do
+      password = "123456789abcd"
+      user = user_fixture(%{password: password})
+
+      {:ok, lv, _html} = live(conn, ~p"/users/log_in")
+
+      form =
+        form(lv, "#login_form", user: %{email: user.email, password: password, remember_me: true})
+
+      conn = submit_form(form, conn)
+
+      assert redirected_to(conn) == ~p"/"
+    end
+
+    test "redirects to login page with a flash error if there are no valid credentials", %{
+      conn: conn
+    } do
+      {:ok, lv, _html} = live(conn, ~p"/users/log_in")
+
+      form =
+        form(lv, "#login_form",
+          user: %{email: "test@email.com", password: "123456", remember_me: true}
+        )
+
+      conn = submit_form(form, conn)
+
+      assert Phoenix.Flash.get(conn.assigns.flash, :error) == "Invalid email or password"
+
+      assert redirected_to(conn) == "/users/log_in"
+    end
+  end
+
+  describe "login navigation" do
+    test "redirects to registration page when the Register button is clicked", %{conn: conn} do
+      {:ok, lv, _html} = live(conn, ~p"/users/log_in")
+
+      {:ok, _login_live, login_html} =
+        lv
+        |> element(~s|main a:fl-contains("Sign up")|)
+        |> render_click()
+        |> follow_redirect(conn, ~p"/users/register")
+
+      assert login_html =~ "Register"
+    end
+
+    test "redirects to forgot password page when the Forgot Password button is clicked", %{
+      conn: conn
+    } do
+      {:ok, lv, _html} = live(conn, ~p"/users/log_in")
+
+      {:ok, conn} =
+        lv
+        |> element(~s|main a:fl-contains("Forgot your password?")|)
+        |> render_click()
+        |> follow_redirect(conn, ~p"/users/reset_password")
+
+      assert conn.resp_body =~ "Forgot your password?"
+    end
+  end
+end

pento/test/pento_web/live/user_registration_live_test.exs

@@ -0,0 +1,87 @@
+defmodule PentoWeb.UserRegistrationLiveTest do
+  use PentoWeb.ConnCase, async: true
+
+  import Phoenix.LiveViewTest
+  import Pento.AccountsFixtures
+
+  describe "Registration page" do
+    test "renders registration page", %{conn: conn} do
+      {:ok, _lv, html} = live(conn, ~p"/users/register")
+
+      assert html =~ "Register"
+      assert html =~ "Log in"
+    end
+
+    test "redirects if already logged in", %{conn: conn} do
+      result =
+        conn
+        |> log_in_user(user_fixture())
+        |> live(~p"/users/register")
+        |> follow_redirect(conn, "/")
+
+      assert {:ok, _conn} = result
+    end
+
+    test "renders errors for invalid data", %{conn: conn} do
+      {:ok, lv, _html} = live(conn, ~p"/users/register")
+
+      result =
+        lv
+        |> element("#registration_form")
+        |> render_change(user: %{"email" => "with spaces", "password" => "too short"})
+
+      assert result =~ "Register"
+      assert result =~ "must have the @ sign and no spaces"
+      assert result =~ "should be at least 12 character"
+    end
+  end
+
+  describe "register user" do
+    test "creates account and logs the user in", %{conn: conn} do
+      {:ok, lv, _html} = live(conn, ~p"/users/register")
+
+      email = unique_user_email()
+      form = form(lv, "#registration_form", user: valid_user_attributes(email: email))
+      render_submit(form)
+      conn = follow_trigger_action(form, conn)
+
+      assert redirected_to(conn) == ~p"/"
+
+      # Now do a logged in request and assert on the menu
+      conn = get(conn, "/")
+      response = html_response(conn, 200)
+      assert response =~ email
+      assert response =~ "Settings"
+      assert response =~ "Log out"
+    end
+
+    test "renders errors for duplicated email", %{conn: conn} do
+      {:ok, lv, _html} = live(conn, ~p"/users/register")
+
+      user = user_fixture(%{email: "test@email.com"})
+
+      result =
+        lv
+        |> form("#registration_form",
+          user: %{"email" => user.email, "password" => "valid_password"}
+        )
+        |> render_submit()
+
+      assert result =~ "has already been taken"
+    end
+  end
+
+  describe "registration navigation" do
+    test "redirects to login page when the Log in button is clicked", %{conn: conn} do
+      {:ok, lv, _html} = live(conn, ~p"/users/register")
+
+      {:ok, _login_live, login_html} =
+        lv
+        |> element(~s|main a:fl-contains("Log in")|)
+        |> render_click()
+        |> follow_redirect(conn, ~p"/users/log_in")
+
+      assert login_html =~ "Log in"
+    end
+  end
+end

pento/test/pento_web/live/user_reset_password_live_test.exs

@@ -0,0 +1,118 @@
+defmodule PentoWeb.UserResetPasswordLiveTest do
+  use PentoWeb.ConnCase, async: true
+
+  import Phoenix.LiveViewTest
+  import Pento.AccountsFixtures
+
+  alias Pento.Accounts
+
+  setup do
+    user = user_fixture()
+
+    token =
+      extract_user_token(fn url ->
+        Accounts.deliver_user_reset_password_instructions(user, url)
+      end)
+
+    %{token: token, user: user}
+  end
+
+  describe "Reset password page" do
+    test "renders reset password with valid token", %{conn: conn, token: token} do
+      {:ok, _lv, html} = live(conn, ~p"/users/reset_password/#{token}")
+
+      assert html =~ "Reset Password"
+    end
+
+    test "does not render reset password with invalid token", %{conn: conn} do
+      {:error, {:redirect, to}} = live(conn, ~p"/users/reset_password/invalid")
+
+      assert to == %{
+               flash: %{"error" => "Reset password link is invalid or it has expired."},
+               to: ~p"/"
+             }
+    end
+
+    test "renders errors for invalid data", %{conn: conn, token: token} do
+      {:ok, lv, _html} = live(conn, ~p"/users/reset_password/#{token}")
+
+      result =
+        lv
+        |> element("#reset_password_form")
+        |> render_change(
+          user: %{"password" => "secret12", "password_confirmation" => "secret123456"}
+        )
+
+      assert result =~ "should be at least 12 character"
+      assert result =~ "does not match password"
+    end
+  end
+
+  describe "Reset Password" do
+    test "resets password once", %{conn: conn, token: token, user: user} do
+      {:ok, lv, _html} = live(conn, ~p"/users/reset_password/#{token}")
+
+      {:ok, conn} =
+        lv
+        |> form("#reset_password_form",
+          user: %{
+            "password" => "new valid password",
+            "password_confirmation" => "new valid password"
+          }
+        )
+        |> render_submit()
+        |> follow_redirect(conn, ~p"/users/log_in")
+
+      refute get_session(conn, :user_token)
+      assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "Password reset successfully"
+      assert Accounts.get_user_by_email_and_password(user.email, "new valid password")
+    end
+
+    test "does not reset password on invalid data", %{conn: conn, token: token} do
+      {:ok, lv, _html} = live(conn, ~p"/users/reset_password/#{token}")
+
+      result =
+        lv
+        |> form("#reset_password_form",
+          user: %{
+            "password" => "too short",
+            "password_confirmation" => "does not match"
+          }
+        )
+        |> render_submit()
+
+      assert result =~ "Reset Password"
+      assert result =~ "should be at least 12 character(s)"
+      assert result =~ "does not match password"
+    end
+  end
+
+  describe "Reset password navigation" do
+    test "redirects to login page when the Log in button is clicked", %{conn: conn, token: token} do
+      {:ok, lv, _html} = live(conn, ~p"/users/reset_password/#{token}")
+
+      {:ok, conn} =
+        lv
+        |> element(~s|main a:fl-contains("Log in")|)
+        |> render_click()
+        |> follow_redirect(conn, ~p"/users/log_in")
+
+      assert conn.resp_body =~ "Log in"
+    end
+
+    test "redirects to registration page when the Register button is clicked", %{
+      conn: conn,
+      token: token
+    } do
+      {:ok, lv, _html} = live(conn, ~p"/users/reset_password/#{token}")
+
+      {:ok, conn} =
+        lv
+        |> element(~s|main a:fl-contains("Register")|)
+        |> render_click()
+        |> follow_redirect(conn, ~p"/users/register")
+
+      assert conn.resp_body =~ "Register"
+    end
+  end
+end

pento/test/pento_web/live/user_settings_live_test.exs

@@ -0,0 +1,210 @@
+defmodule PentoWeb.UserSettingsLiveTest do
+  use PentoWeb.ConnCase, async: true
+
+  alias Pento.Accounts
+  import Phoenix.LiveViewTest
+  import Pento.AccountsFixtures
+
+  describe "Settings page" do
+    test "renders settings page", %{conn: conn} do
+      {:ok, _lv, html} =
+        conn
+        |> log_in_user(user_fixture())
+        |> live(~p"/users/settings")
+
+      assert html =~ "Change Email"
+      assert html =~ "Change Password"
+    end
+
+    test "redirects if user is not logged in", %{conn: conn} do
+      assert {:error, redirect} = live(conn, ~p"/users/settings")
+
+      assert {:redirect, %{to: path, flash: flash}} = redirect
+      assert path == ~p"/users/log_in"
+      assert %{"error" => "You must log in to access this page."} = flash
+    end
+  end
+
+  describe "update email form" do
+    setup %{conn: conn} do
+      password = valid_user_password()
+      user = user_fixture(%{password: password})
+      %{conn: log_in_user(conn, user), user: user, password: password}
+    end
+
+    test "updates the user email", %{conn: conn, password: password, user: user} do
+      new_email = unique_user_email()
+
+      {:ok, lv, _html} = live(conn, ~p"/users/settings")
+
+      result =
+        lv
+        |> form("#email_form", %{
+          "current_password" => password,
+          "user" => %{"email" => new_email}
+        })
+        |> render_submit()
+
+      assert result =~ "A link to confirm your email"
+      assert Accounts.get_user_by_email(user.email)
+    end
+
+    test "renders errors with invalid data (phx-change)", %{conn: conn} do
+      {:ok, lv, _html} = live(conn, ~p"/users/settings")
+
+      result =
+        lv
+        |> element("#email_form")
+        |> render_change(%{
+          "action" => "update_email",
+          "current_password" => "invalid",
+          "user" => %{"email" => "with spaces"}
+        })
+
+      assert result =~ "Change Email"
+      assert result =~ "must have the @ sign and no spaces"
+    end
+
+    test "renders errors with invalid data (phx-submit)", %{conn: conn, user: user} do
+      {:ok, lv, _html} = live(conn, ~p"/users/settings")
+
+      result =
+        lv
+        |> form("#email_form", %{
+          "current_password" => "invalid",
+          "user" => %{"email" => user.email}
+        })
+        |> render_submit()
+
+      assert result =~ "Change Email"
+      assert result =~ "did not change"
+      assert result =~ "is not valid"
+    end
+  end
+
+  describe "update password form" do
+    setup %{conn: conn} do
+      password = valid_user_password()
+      user = user_fixture(%{password: password})
+      %{conn: log_in_user(conn, user), user: user, password: password}
+    end
+
+    test "updates the user password", %{conn: conn, user: user, password: password} do
+      new_password = valid_user_password()
+
+      {:ok, lv, _html} = live(conn, ~p"/users/settings")
+
+      form =
+        form(lv, "#password_form", %{
+          "current_password" => password,
+          "user" => %{
+            "email" => user.email,
+            "password" => new_password,
+            "password_confirmation" => new_password
+          }
+        })
+
+      render_submit(form)
+
+      new_password_conn = follow_trigger_action(form, conn)
+
+      assert redirected_to(new_password_conn) == ~p"/users/settings"
+
+      assert get_session(new_password_conn, :user_token) != get_session(conn, :user_token)
+
+      assert Phoenix.Flash.get(new_password_conn.assigns.flash, :info) =~
+               "Password updated successfully"
+
+      assert Accounts.get_user_by_email_and_password(user.email, new_password)
+    end
+
+    test "renders errors with invalid data (phx-change)", %{conn: conn} do
+      {:ok, lv, _html} = live(conn, ~p"/users/settings")
+
+      result =
+        lv
+        |> element("#password_form")
+        |> render_change(%{
+          "current_password" => "invalid",
+          "user" => %{
+            "password" => "too short",
+            "password_confirmation" => "does not match"
+          }
+        })
+
+      assert result =~ "Change Password"
+      assert result =~ "should be at least 12 character(s)"
+      assert result =~ "does not match password"
+    end
+
+    test "renders errors with invalid data (phx-submit)", %{conn: conn} do
+      {:ok, lv, _html} = live(conn, ~p"/users/settings")
+
+      result =
+        lv
+        |> form("#password_form", %{
+          "current_password" => "invalid",
+          "user" => %{
+            "password" => "too short",
+            "password_confirmation" => "does not match"
+          }
+        })
+        |> render_submit()
+
+      assert result =~ "Change Password"
+      assert result =~ "should be at least 12 character(s)"
+      assert result =~ "does not match password"
+      assert result =~ "is not valid"
+    end
+  end
+
+  describe "confirm email" do
+    setup %{conn: conn} do
+      user = user_fixture()
+      email = unique_user_email()
+
+      token =
+        extract_user_token(fn url ->
+          Accounts.deliver_user_update_email_instructions(%{user | email: email}, user.email, url)
+        end)
+
+      %{conn: log_in_user(conn, user), token: token, email: email, user: user}
+    end
+
+    test "updates the user email once", %{conn: conn, user: user, token: token, email: email} do
+      {:error, redirect} = live(conn, ~p"/users/settings/confirm_email/#{token}")
+
+      assert {:live_redirect, %{to: path, flash: flash}} = redirect
+      assert path == ~p"/users/settings"
+      assert %{"info" => message} = flash
+      assert message == "Email changed successfully."
+      refute Accounts.get_user_by_email(user.email)
+      assert Accounts.get_user_by_email(email)
+
+      # use confirm token again
+      {:error, redirect} = live(conn, ~p"/users/settings/confirm_email/#{token}")
+      assert {:live_redirect, %{to: path, flash: flash}} = redirect
+      assert path == ~p"/users/settings"
+      assert %{"error" => message} = flash
+      assert message == "Email change link is invalid or it has expired."
+    end
+
+    test "does not update email with invalid token", %{conn: conn, user: user} do
+      {:error, redirect} = live(conn, ~p"/users/settings/confirm_email/oops")
+      assert {:live_redirect, %{to: path, flash: flash}} = redirect
+      assert path == ~p"/users/settings"
+      assert %{"error" => message} = flash
+      assert message == "Email change link is invalid or it has expired."
+      assert Accounts.get_user_by_email(user.email)
+    end
+
+    test "redirects if user is not logged in", %{token: token} do
+      conn = build_conn()
+      {:error, redirect} = live(conn, ~p"/users/settings/confirm_email/#{token}")
+      assert {:redirect, %{to: path, flash: flash}} = redirect
+      assert path == ~p"/users/log_in"
+      assert %{"error" => message} = flash
+      assert message == "You must log in to access this page."
+    end
+  end
+end

pento/test/pento_web/user_auth_test.exs

@@ -0,0 +1,272 @@
+defmodule PentoWeb.UserAuthTest do
+  use PentoWeb.ConnCase, async: true
+
+  alias Phoenix.LiveView
+  alias Pento.Accounts
+  alias PentoWeb.UserAuth
+  import Pento.AccountsFixtures
+
+  @remember_me_cookie "_pento_web_user_remember_me"
+
+  setup %{conn: conn} do
+    conn =
+      conn
+      |> Map.replace!(:secret_key_base, PentoWeb.Endpoint.config(:secret_key_base))
+      |> init_test_session(%{})
+
+    %{user: user_fixture(), conn: conn}
+  end
+
+  describe "log_in_user/3" do
+    test "stores the user token in the session", %{conn: conn, user: user} do
+      conn = UserAuth.log_in_user(conn, user)
+      assert token = get_session(conn, :user_token)
+      assert get_session(conn, :live_socket_id) == "users_sessions:#{Base.url_encode64(token)}"
+      assert redirected_to(conn) == ~p"/"
+      assert Accounts.get_user_by_session_token(token)
+    end
+
+    test "clears everything previously stored in the session", %{conn: conn, user: user} do
+      conn = conn |> put_session(:to_be_removed, "value") |> UserAuth.log_in_user(user)
+      refute get_session(conn, :to_be_removed)
+    end
+
+    test "redirects to the configured path", %{conn: conn, user: user} do
+      conn = conn |> put_session(:user_return_to, "/hello") |> UserAuth.log_in_user(user)
+      assert redirected_to(conn) == "/hello"
+    end
+
+    test "writes a cookie if remember_me is configured", %{conn: conn, user: user} do
+      conn = conn |> fetch_cookies() |> UserAuth.log_in_user(user, %{"remember_me" => "true"})
+      assert get_session(conn, :user_token) == conn.cookies[@remember_me_cookie]
+
+      assert %{value: signed_token, max_age: max_age} = conn.resp_cookies[@remember_me_cookie]
+      assert signed_token != get_session(conn, :user_token)
+      assert max_age == 5_184_000
+    end
+  end
+
+  describe "logout_user/1" do
+    test "erases session and cookies", %{conn: conn, user: user} do
+      user_token = Accounts.generate_user_session_token(user)
+
+      conn =
+        conn
+        |> put_session(:user_token, user_token)
+        |> put_req_cookie(@remember_me_cookie, user_token)
+        |> fetch_cookies()
+        |> UserAuth.log_out_user()
+
+      refute get_session(conn, :user_token)
+      refute conn.cookies[@remember_me_cookie]
+      assert %{max_age: 0} = conn.resp_cookies[@remember_me_cookie]
+      assert redirected_to(conn) == ~p"/"
+      refute Accounts.get_user_by_session_token(user_token)
+    end
+
+    test "broadcasts to the given live_socket_id", %{conn: conn} do
+      live_socket_id = "users_sessions:abcdef-token"
+      PentoWeb.Endpoint.subscribe(live_socket_id)
+
+      conn
+      |> put_session(:live_socket_id, live_socket_id)
+      |> UserAuth.log_out_user()
+
+      assert_receive %Phoenix.Socket.Broadcast{event: "disconnect", topic: ^live_socket_id}
+    end
+
+    test "works even if user is already logged out", %{conn: conn} do
+      conn = conn |> fetch_cookies() |> UserAuth.log_out_user()
+      refute get_session(conn, :user_token)
+      assert %{max_age: 0} = conn.resp_cookies[@remember_me_cookie]
+      assert redirected_to(conn) == ~p"/"
+    end
+  end
+
+  describe "fetch_current_user/2" do
+    test "authenticates user from session", %{conn: conn, user: user} do
+      user_token = Accounts.generate_user_session_token(user)
+      conn = conn |> put_session(:user_token, user_token) |> UserAuth.fetch_current_user([])
+      assert conn.assigns.current_user.id == user.id
+    end
+
+    test "authenticates user from cookies", %{conn: conn, user: user} do
+      logged_in_conn =
+        conn |> fetch_cookies() |> UserAuth.log_in_user(user, %{"remember_me" => "true"})
+
+      user_token = logged_in_conn.cookies[@remember_me_cookie]
+      %{value: signed_token} = logged_in_conn.resp_cookies[@remember_me_cookie]
+
+      conn =
+        conn
+        |> put_req_cookie(@remember_me_cookie, signed_token)
+        |> UserAuth.fetch_current_user([])
+
+      assert conn.assigns.current_user.id == user.id
+      assert get_session(conn, :user_token) == user_token
+
+      assert get_session(conn, :live_socket_id) ==
+               "users_sessions:#{Base.url_encode64(user_token)}"
+    end
+
+    test "does not authenticate if data is missing", %{conn: conn, user: user} do
+      _ = Accounts.generate_user_session_token(user)
+      conn = UserAuth.fetch_current_user(conn, [])
+      refute get_session(conn, :user_token)
+      refute conn.assigns.current_user
+    end
+  end
+
+  describe "on_mount :mount_current_user" do
+    test "assigns current_user based on a valid user_token", %{conn: conn, user: user} do
+      user_token = Accounts.generate_user_session_token(user)
+      session = conn |> put_session(:user_token, user_token) |> get_session()
+
+      {:cont, updated_socket} =
+        UserAuth.on_mount(:mount_current_user, %{}, session, %LiveView.Socket{})
+
+      assert updated_socket.assigns.current_user.id == user.id
+    end
+
+    test "assigns nil to current_user assign if there isn't a valid user_token", %{conn: conn} do
+      user_token = "invalid_token"
+      session = conn |> put_session(:user_token, user_token) |> get_session()
+
+      {:cont, updated_socket} =
+        UserAuth.on_mount(:mount_current_user, %{}, session, %LiveView.Socket{})
+
+      assert updated_socket.assigns.current_user == nil
+    end
+
+    test "assigns nil to current_user assign if there isn't a user_token", %{conn: conn} do
+      session = conn |> get_session()
+
+      {:cont, updated_socket} =
+        UserAuth.on_mount(:mount_current_user, %{}, session, %LiveView.Socket{})
+
+      assert updated_socket.assigns.current_user == nil
+    end
+  end
+
+  describe "on_mount :ensure_authenticated" do
+    test "authenticates current_user based on a valid user_token", %{conn: conn, user: user} do
+      user_token = Accounts.generate_user_session_token(user)
+      session = conn |> put_session(:user_token, user_token) |> get_session()
+
+      {:cont, updated_socket} =
+        UserAuth.on_mount(:ensure_authenticated, %{}, session, %LiveView.Socket{})
+
+      assert updated_socket.assigns.current_user.id == user.id
+    end
+
+    test "redirects to login page if there isn't a valid user_token", %{conn: conn} do
+      user_token = "invalid_token"
+      session = conn |> put_session(:user_token, user_token) |> get_session()
+
+      socket = %LiveView.Socket{
+        endpoint: PentoWeb.Endpoint,
+        assigns: %{__changed__: %{}, flash: %{}}
+      }
+
+      {:halt, updated_socket} = UserAuth.on_mount(:ensure_authenticated, %{}, session, socket)
+      assert updated_socket.assigns.current_user == nil
+    end
+
+    test "redirects to login page if there isn't a user_token", %{conn: conn} do
+      session = conn |> get_session()
+
+      socket = %LiveView.Socket{
+        endpoint: PentoWeb.Endpoint,
+        assigns: %{__changed__: %{}, flash: %{}}
+      }
+
+      {:halt, updated_socket} = UserAuth.on_mount(:ensure_authenticated, %{}, session, socket)
+      assert updated_socket.assigns.current_user == nil
+    end
+  end
+
+  describe "on_mount :redirect_if_user_is_authenticated" do
+    test "redirects if there is an authenticated  user ", %{conn: conn, user: user} do
+      user_token = Accounts.generate_user_session_token(user)
+      session = conn |> put_session(:user_token, user_token) |> get_session()
+
+      assert {:halt, _updated_socket} =
+               UserAuth.on_mount(
+                 :redirect_if_user_is_authenticated,
+                 %{},
+                 session,
+                 %LiveView.Socket{}
+               )
+    end
+
+    test "doesn't redirect if there is no authenticated user", %{conn: conn} do
+      session = conn |> get_session()
+
+      assert {:cont, _updated_socket} =
+               UserAuth.on_mount(
+                 :redirect_if_user_is_authenticated,
+                 %{},
+                 session,
+                 %LiveView.Socket{}
+               )
+    end
+  end
+
+  describe "redirect_if_user_is_authenticated/2" do
+    test "redirects if user is authenticated", %{conn: conn, user: user} do
+      conn = conn |> assign(:current_user, user) |> UserAuth.redirect_if_user_is_authenticated([])
+      assert conn.halted
+      assert redirected_to(conn) == ~p"/"
+    end
+
+    test "does not redirect if user is not authenticated", %{conn: conn} do
+      conn = UserAuth.redirect_if_user_is_authenticated(conn, [])
+      refute conn.halted
+      refute conn.status
+    end
+  end
+
+  describe "require_authenticated_user/2" do
+    test "redirects if user is not authenticated", %{conn: conn} do
+      conn = conn |> fetch_flash() |> UserAuth.require_authenticated_user([])
+      assert conn.halted
+
+      assert redirected_to(conn) == ~p"/users/log_in"
+
+      assert Phoenix.Flash.get(conn.assigns.flash, :error) ==
+               "You must log in to access this page."
+    end
+
+    test "stores the path to redirect to on GET", %{conn: conn} do
+      halted_conn =
+        %{conn | path_info: ["foo"], query_string: ""}
+        |> fetch_flash()
+        |> UserAuth.require_authenticated_user([])
+
+      assert halted_conn.halted
+      assert get_session(halted_conn, :user_return_to) == "/foo"
+
+      halted_conn =
+        %{conn | path_info: ["foo"], query_string: "bar=baz"}
+        |> fetch_flash()
+        |> UserAuth.require_authenticated_user([])
+
+      assert halted_conn.halted
+      assert get_session(halted_conn, :user_return_to) == "/foo?bar=baz"
+
+      halted_conn =
+        %{conn | path_info: ["foo"], query_string: "bar", method: "POST"}
+        |> fetch_flash()
+        |> UserAuth.require_authenticated_user([])
+
+      assert halted_conn.halted
+      refute get_session(halted_conn, :user_return_to)
+    end
+
+    test "does not redirect if user is authenticated", %{conn: conn, user: user} do
+      conn = conn |> assign(:current_user, user) |> UserAuth.require_authenticated_user([])
+      refute conn.halted
+      refute conn.status
+    end
+  end
+end

pento/test/support/conn_case.ex

@@ -35,4 +35,30 @@ defmodule PentoWeb.ConnCase do
     Pento.DataCase.setup_sandbox(tags)
     {:ok, conn: Phoenix.ConnTest.build_conn()}
   end
+
+  @doc """
+  Setup helper that registers and logs in users.
+
+      setup :register_and_log_in_user
+
+  It stores an updated connection and a registered user in the
+  test context.
+  """
+  def register_and_log_in_user(%{conn: conn}) do
+    user = Pento.AccountsFixtures.user_fixture()
+    %{conn: log_in_user(conn, user), user: user}
+  end
+
+  @doc """
+  Logs the given `user` into the `conn`.
+
+  It returns an updated `conn`.
+  """
+  def log_in_user(conn, user) do
+    token = Pento.Accounts.generate_user_session_token(user)
+
+    conn
+    |> Phoenix.ConnTest.init_test_session(%{})
+    |> Plug.Conn.put_session(:user_token, token)
+  end
 end

pento/test/support/fixtures/accounts_fixtures.ex

@@ -0,0 +1,31 @@
+defmodule Pento.AccountsFixtures do
+  @moduledoc """
+  This module defines test helpers for creating
+  entities via the `Pento.Accounts` context.
+  """
+
+  def unique_user_email, do: "user#{System.unique_integer()}@example.com"
+  def valid_user_password, do: "hello world!"
+
+  def valid_user_attributes(attrs \\ %{}) do
+    Enum.into(attrs, %{
+      email: unique_user_email(),
+      password: valid_user_password()
+    })
+  end
+
+  def user_fixture(attrs \\ %{}) do
+    {:ok, user} =
+      attrs
+      |> valid_user_attributes()
+      |> Pento.Accounts.register_user()
+
+    user
+  end
+
+  def extract_user_token(fun) do
+    {:ok, captured_email} = fun.(&"[TOKEN]#{&1}[TOKEN]")
+    [_, token | _] = String.split(captured_email.text_body, "[TOKEN]")
+    token
+  end
+end