Implementation of a basic test framework for IEx. Closes elixir-lang#919

Author: alco

lib/ex_unit/lib/ex_unit/callbacks.ex

@@ -29,6 +29,11 @@ defmodule ExUnit.Callbacks do
           :ok
         end
 
+        teardown context do
+          assert context[:hello] == "world"
+          :ok
+        end
+
         test "always pass" do
           assert true
         end

lib/iex/lib/iex.ex

@@ -205,7 +205,11 @@ defmodule IEx do
     :application.start(:iex)
   end
 
-  defp boot_config(opts) do
+  @doc """
+  Returns default config used to launch IEx. This config is also used by
+  IEx.TestFramework.
+  """
+  def boot_config(opts) do
     scope = :elixir.scope_for_eval(
       file: "iex",
       delegate_locals_to: IEx.Helpers

lib/iex/test/iex/helpers_test.exs

@@ -0,0 +1,28 @@
+Code.require_file "../test_helper.exs", __DIR__
+
+defmodule IEx.Helpers.Test do
+  use IEx.Case
+
+  test "h helper" do
+    assert "# IEx.Helpers\n\nWelcome to Interactive Elixir" <> _ = capture_iex("h")
+  end
+
+  test "h helper module" do
+    assert "# Enumerable\n\nThis is the protocol used by the `Enum` module" <> _ = capture_iex("h Enumerable")
+    assert capture_iex("h :whatever") == "Could not load module :whatever: nofile\n:ok"
+  end
+
+  test "h helper function" do
+    expand_1_re = %r/\* def expand\(path\)\n\nConverts the path to an absolute one and expands/
+    expand_2_re = %r/\* def expand\(path, relative_to\)\n\nExpands the path relative to the path given as the second argument/
+
+    assert capture_iex("h Path.expand/1") =~ expand_1_re
+    assert capture_iex("h Path.expand/2") =~ expand_2_re
+
+    output = capture_iex("h Path.expand")
+    assert output =~ expand_1_re
+    assert output =~ expand_2_re
+
+    assert capture_iex("h pwd") == "* def pwd()\n\nPrints the current working directory.\n\n:ok"
+  end
+end

lib/iex/test/iex/interaction_test.exs

@@ -0,0 +1,71 @@
+Code.require_file "../test_helper.exs", __DIR__
+
+defmodule IEx.InteractionTest do
+  use IEx.Case
+
+  ### basic interaction ###
+
+  test "empty input" do
+    assert capture_iex("\n") == "nil"
+  end
+
+  test "normal input" do
+    assert capture_iex("1 + 2") == "3"
+  end
+
+  test "exception" do
+    assert capture_iex("1 + :atom\n:this_is_still_working") =~ %r/^#{iex_format_exception(ArithmeticError,
+      "bad argument in arithmetic expression")}.+\n:this_is_still_working$/s
+  end
+
+  test "empty history at the start" do
+    assert "** (RuntimeError) Out of bounds" <> _ = capture_iex("v(-1)")
+  end
+
+  test "empty history at the start redux" do
+    assert "** (RuntimeError) Out of bounds" <> _ = capture_iex("v(1)")
+  end
+
+  test "no break" do
+    input = """
+      ["a
+      b
+      c
+    """
+    assert capture_iex(input) == ""
+  end
+
+  test "break" do
+    input = """
+      ["a
+      b
+      c
+    #iex:break
+    """
+    assert "** (TokenMissingError) iex:1: incomplete expression" <> _ = capture_iex(input)
+  end
+
+  ### .iex file loading ###
+
+  test "no .iex" do
+    assert "** (UndefinedFunctionError) undefined function: IEx.Helpers.my_variable/0" <> _ = capture_iex("my_variable")
+  end
+
+  test ".iex" do
+    File.write!("dot-iex", "my_variable = 144")
+    assert capture_iex("my_variable", [], "dot-iex") == "144"
+  after
+    File.rm!("dot-iex")
+  end
+
+  test "nested .iex" do
+    File.write!("dot-iex-1", "nested_var = 13\nimport IO")
+    File.write!("dot-iex", "import_file \"dot-iex-1\"\nmy_variable=14")
+
+    input = "nested_var\nmy_variable\nputs \"hello\""
+    assert capture_iex(input, [], "dot-iex") == "13\n14\nhello\n:ok"
+  after
+    File.rm("dot-iex-1")
+    File.rm!("dot-iex")
+  end
+end

lib/iex/test/iex/options_test.exs

@@ -0,0 +1,28 @@
+Code.require_file "../test_helper.exs", __DIR__
+
+defmodule IEx.Options.Test do
+  use IEx.Case
+
+  test "color" do
+    opts = [colors: [enabled: true, eval_result: "red"]]
+    assert capture_iex("1 + 2", opts) == "\e[31m3\e[0m"
+  end
+
+  test "inspect opts" do
+    opts = [inspect: [limit: 3, raw: true]]
+    assert capture_iex("[1,2,3,4,5]\nArgumentError[]", opts) ==
+              "[1,2,3,...]\n{ArgumentError,:__exception__,\"argument error\"}"
+
+    opts = [inspect: [raw: false]]
+    assert capture_iex("ArgumentError[]", opts) == "ArgumentError[message: \"argument error\"]"
+  end
+
+  test "history size" do
+    opts = [history_size: 3]
+    assert capture_iex("1\n2\n3\nv(1)", opts) == "1\n2\n3\n1"
+    assert "1\n2\n3\n4\n** (RuntimeError) Out of bounds" <> _ = capture_iex("1\n2\n3\n4\nv(1)", opts)
+    assert "1\n2\n3\n4\n** (RuntimeError) Out of bounds" <> _ = capture_iex("1\n2\n3\n4\nv(-4)", opts)
+    assert "1\n2\n3\n4\n2\n** (RuntimeError) Out of bounds" <> _ = capture_iex("1\n2\n3\n4\nv(2)\nv(2)", opts)
+  end
+end
+

lib/iex/test/test_helper.exs

@@ -1,2 +1,55 @@
 :application.start(:iex)
-ExUnit.start []
+ExUnit.start []
+
+defmodule IEx.Case do
+  defmacro __using__(_) do
+    quote do
+      use ExUnit.Case, async: false
+      import unquote(__MODULE__)
+
+      setup do
+        opts = IEx.Options.get
+        IEx.Options.set :colors, [enabled: false]
+        { :ok, [iex_opts: opts] }
+      end
+
+      teardown context do
+        IEx.Options.set context[:iex_opts]
+        :ok
+      end
+    end
+  end
+
+  def capture_iex(input, options // [], dot_iex_path // "") do
+    Enum.each options, fn { opt, value } ->
+      IEx.Options.set(opt, value)
+    end
+
+    ExUnit.CaptureIO.capture_io(input, fn ->
+      IEx.Server.start(iex_config(dot_iex_path: dot_iex_path))
+    end) |> strip_iex
+  end
+
+  def iex_exception(name, message // "") do
+    %r/#{iex_format_exception(name, message)}/
+  end
+
+  def iex_format_exception(name, message // "") do
+    "\\*\\* \\(#{Module.to_binary name}\\) (.*?)#{message}"
+  end
+
+  defp iex_config(opts) do
+    IEx.boot_config(opts)
+  end
+
+  defp strip_iex(string) do
+    string
+    |> strip_line   # strip the greeting
+    |> String.strip
+  end
+
+  defp strip_line(string) do
+    Regex.replace %r/\A.+?$/ms, string, ""
+  end
+end
+