How to run tests with mix

Question

Update: for anyone arriving at this question from Google, you can run the tests of a given Elixir project by running mix test .

As per the docs , Elixir Script Files (with an extension of .exs) do not need to be compiled before they are ran.

Here is an exact quote from the Elixir docs:

the test file is an Elixir script file (.exs). This is convenient because we don't need to compile test files before running them

---

So I am adding a module file and test file to the faker library here

I have already compiled the project by running mix compile in the project root.

The problem arises when I attempt to run all the test files in addition to my new test file, using mix test . I receive the following error:

** (CompileError) test/faker/shakespeare_test.exs:3: module Faker.Shakespeare is not loaded and could not be found
    (stdlib) lists.erl:1353: :lists.mapfoldl/3
    (stdlib) lists.erl:1354: :lists.mapfoldl/3

The error says that the module couldn't be found, but it's clearly in bin. What am I doing wrong?

The contents of lib/Shakespeare.ex are:

defmodule Shakespeare do

  def hamlet_quote do
    Enum.at(hamlet, :crypto.rand_uniform(0, Enum.count(hamlet)))
  end

  def as_you_like_it_quote do
    Enum.at(as_you_like_it, :crypto.rand_uniform(0, Enum.count(as_you_like_it)))
  end

  def king_richard_iii_quote do
    Enum.at(king_richard_iii, :crypto.rand_uniform(0, Enum.count(king_richard_iii)))
  end

  def romeo_and_juliet_quote do
    Enum.at(romeo_and_juliet, :crypto.rand_uniform(0, Enum.count(romeo_and_juliet)))
  end

  def hamlet do
      ["To be, or not to be: that is the question.",
       "Neither a borrower nor a lender be; For loan oft loses both itself and friend, and borrowing dulls the edge of husbandry.",
       "This above all: to thine own self be true.",
       "Though this be madness, yet there is method in 't.",
       "That it should come to this!.",
       "There is nothing either good or bad, but thinking makes it so.",
       "What a piece of work is man! how noble in reason! how infinite in faculty! in form and moving how express and admirable! in action how like an angel! in apprehension how like a god! the beauty of the world, the paragon of animals! .",
       "The lady doth protest too much, methinks.",
       "In my mind's eye.",
       "A little more than kin, and less than kind.",
       "The play 's the thing wherein I'll catch the conscience of the king.",
       "And it must follow, as the night the day, thou canst not then be false to any man.",
       "Brevity is the soul of wit.",
       "Doubt that the sun doth move, doubt truth to be a liar, but never doubt I love.",
       "Rich gifts wax poor when givers prove unkind.",
       "Do you think I am easier to be played on than a pipe?",
       "I will speak daggers to her, but use none.",
       "When sorrows come, they come not single spies, but in battalions."]
  end

  def as_you_like_it do
      ["All the world 's a stage, and all the men and women merely players. They have their exits and their entrances; And one man in his time plays many parts.",
       "Can one desire too much of a good thing?.",
       "I like this place and willingly could waste my time in it.",
       "How bitter a thing it is to look into happiness through another man's eyes!",
       "Blow, blow, thou winter wind! Thou art not so unkind as man's ingratitude.",
       "True is it that we have seen better days.",
       "For ever and a day.",
       "The fool doth think he is wise, but the wise man knows himself to be a fool."]
  end

  def king_richard_iii do
      ["Now is the winter of our discontent.",
       "A horse! a horse! my kingdom for a horse!.",
       "Conscience is but a word that cowards use, devised at first to keep the strong in awe.",
       "So wise so young, they say, do never live long.",
       "Off with his head!",
       "An honest tale speeds best, being plainly told.",
       "The king's name is a tower of strength.",
       "The world is grown so bad, that wrens make prey where eagles dare not perch."]
  end

  def romeo_and_juliet do
      ["O Romeo, Romeo! wherefore art thou Romeo?.",
       "It is the east, and Juliet is the sun.",
       "Good Night, Good night! Parting is such sweet sorrow, that I shall say good night till it be morrow.",
       "What's in a name? That which we call a rose by any other name would smell as sweet.",
       "Wisely and slow; they stumble that run fast.",
       "Tempt not a desperate man.",
       "For you and I are past our dancing days.",
       "O! she doth teach the torches to burn bright.",
       "It seems she hangs upon the cheek of night like a rich jewel in an Ethiope's ear.",
       "See, how she leans her cheek upon her hand! O that I were a glove upon that hand, that I might touch that cheek!.",
       "Not stepping o'er the bounds of modesty."]
  end

 end

The contents of test/Shakespeare_test.ex is:

defmodule Faker.ShakespeareTest do
  use ExUnit.Case, async: true
  import Faker.Shakespeare

  test :hamlet_quote do
    assert String.length(hamlet_quote) != 0
    assert Regex.match?(~r/.+/, hamlet_quote)
  end

  test :as_you_like_it_quote do
    assert String.length(as_you_like_it_quote) != 0
    assert Regex.match?(~r/.+/, as_you_like_it_quote)
  end

  test :king_richard_iii_quote do
    assert String.length(king_richard_iii_quote) != 0
    assert Regex.match?(~r/.+/, king_richard_iii_quote)
  end

  test :romeo_and_juliet_quote do
    assert String.length(romeo_and_juliet_quote) != 0
    assert Regex.match?(~r/.+/, romeo_and_juliet_quote)
  end
end

Answer 1

You are defining the module (not class) Shakespeare but your tests are using the module Faker.Shakespeare .

If you define your module name correctly as defmodule Faker.Shakespeare , it should work.