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authenticationelixirintegration-testingphoenix-framework

How can I use ExMachina to create an account that I can sign in with?


I'm able to save new Users to the db with my Factory, but I get "invalid username or password" when I try to sign in. How do I create Users with my Factory that I also can sign in with? The User is not valid if I try to insert it without the hashed_password set, but I guess I should not set that manually myself?

Running Phoenix with iex to be sure that I insert the Users in the same environment as I run the server in:

$ iex -S mix phx.server

iex(4)> Factory.insert(:user)
[debug] QUERY OK db=3.6ms queue=1.9ms idle=472.0ms
INSERT INTO "users" ("confirmed_at","email","hashed_password","inserted_at","updated_at") VALUES ($1,$2,$3,$4,$5) RETURNING "id" [~N[2023-08-06 06:00:23], "email-2@example.com", "password", ~N[2023-08-06 06:00:23], ~N[2023-08-06 06:00:23]]
↳ anonymous fn/4 in :elixir.eval_external_handler/1, at: src/elixir.erl:309
#HealthTracker.Accounts.User<
  __meta__: #Ecto.Schema.Metadata<:loaded, "users">,
  id: 9,
  email: "email-2@example.com",
  confirmed_at: ~N[2023-08-06 06:00:23],
  inserted_at: ~N[2023-08-06 06:00:23],
  updated_at: ~N[2023-08-06 06:00:23],
  ...
>

HealthTracker.Factory

defmodule HealthTracker.Factory do
  use ExMachina.Ecto, repo: HealthTracker.Repo

  def user_factory do
    %HealthTracker.Accounts.User{
      email: sequence(:email, &"email-#{&1}@example.com"),
      password: "password",
      hashed_password: "password", # Can save, but invalid content so i can't log in.
      confirmed_at: DateTime.utc_now()
    }
  end

end

HealthTracker.Accounts.User

defmodule HealthTracker.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 :confirmed_at, :naive_datetime

    timestamps()
  end

  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, HealthTracker.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 = NaiveDateTime.utc_now() |> NaiveDateTime.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?(%HealthTracker.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
    if valid_password?(changeset.data, password) do
      changeset
    else
      add_error(changeset, :current_password, "is not valid")
    end
  end
end

Solution

  • I was able to fix it by correctly hashing the password I saved to the database.

    See updated Factory:

    defmodule HealthTracker.Factory do
      use ExMachina.Ecto, repo: HealthTracker.Repo
      alias Bcrypt
    
      def user_factory do
        %HealthTracker.Accounts.User{
          email: sequence(:email, &"email-#{&1}@example.com"),
          password: "password",
          hashed_password: Bcrypt.hash_pwd_salt("password"),
          confirmed_at: DateTime.utc_now()
        }
      end