Strange `CaseClauseError`

Because you are not showing full code? Perhaps do everything in an iex session.

It seems that there is something happening in the meantime. Could you provide us with Minimal Complete and Verifiable Example? Because right now I can say that “it works on my machine”

@NobbZ, @hauleth
My actual problem that led me to debugging that is the following line:
https://github.com/greyhwndz/library_api/blob/master/lib/library_api_web/controllers/session_controller.ex#L12
should return me a token after Postman POST

{
	"email": "juan@hello.com",
	"password": "asdf"
}

to http://localhost:4000/api/session

However, it falls into the rescue section that is why I tried debugging my render view

This is neither minimal nor verifiable example. I still do not get where you put that inspect nor what are the types you are inspecting.

Am sorry @hauleth for being a newbie.
I guess I will try to re-create a new thread and re-phrase my problem. Thanks for the guidance

That is a JWT Token, paste it on jwt.io, but there’s no data inside. So I would guess you are using a JWT token library between your assignment and your IO.inspect.

No need to do this, just update here with more information and we’ll be able to provide a more detailed answer.

Ok @benwilson512. trying now…

@benwilson512, @NobbZ, @hauleth

I have the following code in lib/library_api/library.ex

...
  def get_user_by_email!(email), do: Repo.get_by!(User, email: email)
...

and in my SessionController lib/library_api_web/controllers/session_controller.ex

defmodule LibraryApiWeb.SessionController do
  use LibraryApiWeb, :controller
  alias LibraryApi.Library
  #alias LibraryApi.Library.User

  def create(conn, %{"email" => email, "password" => _password}) do
    case Library.get_user_by_email!(email) do
      {:ok, user} ->
        conn
        |> put_view(LibraryApiWeb.SessionView)
        |> render("token.json", user: user)
      {:error, _reason} ->
        conn
        |> put_status(:unauthorized)
        |> put_view(LibraryApiWeb.ErrorView)
        |> render("401.json-api", %{detail: "Error logging in a user with that email and password"})
    end
  end
end

and in my SessionView: lib/library_api_web/views/session_view.ex

defmodule LibraryApiWeb.SessionView do
  use LibraryApiWeb, :view
  #import Joken.Config

  def render("token.json", %{user: user}) do
    mydata = %{id: user.id, email: user.email, username: user.username}
    jwt = %{data: mydata, sub: user.id}
    |> Joken.generate_and_sign(Joken.Signer.create("HS512", "SOMESECRETVALUE"))
    %{token: jwt.token}
  end
end

In my database I already was able have the following data:

{
	"data": {
		"type": "users",
		"attributes": {
			"email": "maria@hello.com",
			"username": "maria",
			"password": "asdf",
			"password_confirmation": "asdf"
		}
	}
}

NOTE: password & password_confirmation are virtual fields

Using Postman, I am trying to POST to http://localhost:4000/api/session the ff. data:

{
	"email": "maria@hello.com",
	"password": "asdf"
}

that should return a token.
Instead I encounter the following error in my iex console:

iex(1)> [info] POST /api/session
iex(1)> [debug] Processing with LibraryApiWeb.SessionController.create/2
  Parameters: %{"email" => "maria@hello.com", "password" => "[FILTERED]"}
  Pipelines: [:api]
iex(1)> [debug] QUERY OK source="users" db=0.0ms
SELECT u0."id", u0."email", u0."password_hash", u0."username", u0."inserted_at", u0."updated_at" FROM "users" AS u0 WHERE (u0."email" = $1) ["maria@hello.com"]
iex(1)> [info] Converted error {:case_clause, %LibraryApi.Library.User{__meta__: #Ecto.Schema.Metadata<:loaded, "users">, email: "maria@hello.com", id: 4, inserted_at: ~N[2019-05-12 08:41:18], password: nil, password_confirmation: nil, password_hash: "$2b$12$7qHpuOzPJaJShZoO4DCmAe9K/vHvsGwGPRlVmGzHQUlLkCBpgOZ82", updated_at: ~N[2019-05-12 08:41:18], username: "maria"}} to 500 response
iex(1)> [info] Sent 500 in 109ms
iex(1)> [error] #PID<0.435.0> running LibraryApiWeb.Endpoint (connection #PID<0.434.0>, stream id 1) terminated
Server: localhost:4000 (http)
Request: POST /api/session
** (exit) an exception was raised:
    ** (CaseClauseError) no case clause matching: %LibraryApi.Library.User{__meta__: #Ecto.Schema.Metadata<:loaded, "users">, email: "maria@hello.com", id: 4, inserted_at: ~N[2019-05-12 08:41:18], password: nil, password_confirmation: nil, password_hash: "$2b$12$7qHpuOzPJaJShZoO4DCmAe9K/vHvsGwGPRlVmGzHQUlLkCBpgOZ82", updated_at: ~N[2019-05-12 08:41:18], username: "maria"}
        (library_api) lib/library_api_web/controllers/session_controller.ex:7: LibraryApiWeb.SessionController.create/2
        (library_api) lib/library_api_web/controllers/session_controller.ex:1: LibraryApiWeb.SessionController.action/2
        (library_api) lib/library_api_web/controllers/session_controller.ex:1: LibraryApiWeb.SessionController.phoenix_controller_pipeline/2
        (library_api) lib/library_api_web/endpoint.ex:1: LibraryApiWeb.Endpoint.instrument/4
        (phoenix) lib/phoenix/router.ex:275: Phoenix.Router.__call__/1
        (library_api) lib/library_api_web/endpoint.ex:1: LibraryApiWeb.Endpoint.plug_builder_call/2
        (library_api) lib/library_api_web/endpoint.ex:1: LibraryApiWeb.Endpoint.call/2
        (phoenix) lib/phoenix/endpoint/cowboy2_handler.ex:33: Phoenix.Endpoint.Cowboy2Handler.init/2
        (cowboy) d:/@@@/@gilbertc77/library_api/deps/cowboy/src/cowboy_handler.erl:41: :cowboy_handler.execute/2
        (cowboy) d:/@@@/@gilbertc77/library_api/deps/cowboy/src/cowboy_stream_h.erl:296: :cowboy_stream_h.execute/3
        (cowboy) d:/@@@/@gilbertc77/library_api/deps/cowboy/src/cowboy_stream_h.erl:274: :cowboy_stream_h.request_process/3

        (stdlib) proc_lib.erl:249: :proc_lib.init_p_do_apply/3

get_user_by_email! returns a %LibraryApi.Library.User{} not {:ok, %LibraryApi.Library.User{}}, so your case in your controller doesn’t match.

Also, you probably know this, but never store user passwords in the database unhashed.