Stop wrapping ExUnit

Author: ukutaht

config/config.exs

@@ -0,0 +1,3 @@
+use Mix.Config
+
+config :ex_unit, assert_receive_timeout: 100

lib/blank_assertions.ex

@@ -20,4 +20,20 @@ defmodule Blanks do
   defp count(:___, acc), do: {node, acc+1}
   defp count({:___, _, _}, acc), do: {node, acc+1}
   defp count(node, acc), do: {node, acc}
+
+  def replace_line([do: ast], replacement_fn), do: [do: replace_line(ast, replacement_fn)]
+  def replace_line({:__block__, meta, lines}, replacement_fn) do
+    replaced_lines = Enum.map(lines, fn(line) ->
+      replace_line(line, replacement_fn)
+    end)
+
+    {:__block__, meta, replaced_lines}
+  end
+  def replace_line(line, replacement_fn) do
+    if Blanks.count(line) > 0 do
+      replacement_fn.(line)
+    else
+      line
+    end
+  end
 end

lib/blanks.ex

@@ -52,13 +52,9 @@ defmodule Display do
   end
 
   defp format_failure(%{error: %ExUnit.AssertionError{expr: expr}, file: file, line: line}) do
-    format_assertion_error(expr, file, line)
-  end
-
-  defp format_assertion_error(error, file, line) do
     """
     #{format_cyan("Assertion failed in #{file}:#{line}")}
-    #{format_red(Macro.to_string(error))}
+    #{format_red(Macro.to_string(expr))}
     """
   end
 

lib/display.ex

@@ -7,16 +7,19 @@ defmodule Koans do
     if not valid_name(name) do
       raise "Name does not start with a capital ltter: #{name}"
     end
+
     compiled_name = String.to_atom(name)
     number_of_args = Blanks.count(body)
+    compiled_body = Blanks.replace_line(body, &blank_line_replacement/1)
+
     quote do
       @koans unquote(compiled_name)
 
       generate_test_method(unquote(compiled_name), unquote(number_of_args), unquote(body))
 
       def unquote(compiled_name)() do
         try do
-          unquote(body)
+          unquote(compiled_body)
           :ok
         rescue
           e in _ -> e
@@ -47,6 +50,16 @@ defmodule Koans do
     end
   end
 
+  defp blank_line_replacement({:assert, _meta, [expr]}) do
+    code = Macro.escape(expr)
+    quote do: raise ExUnit.AssertionError, expr: unquote(code)
+  end
+
+  defp blank_line_replacement(line) do
+    code = Macro.escape(line)
+    quote do: raise ExUnit.AssertionError, expr: unquote(code)
+  end
+
   defp create_vars(amount) do
     for id <- 0..amount, do: quote do: elem(converted, unquote(id))
   end
@@ -57,8 +70,8 @@ defmodule Koans do
       Module.register_attribute(__MODULE__, :koans, accumulate: true)
 
       require ExUnit.Assertions
+      import ExUnit.Assertions
       import Koans
-      import BlankAssertions
 
       @before_compile Koans
     end

lib/koans.ex

@@ -51,4 +51,38 @@ defmodule BlanksTest do
 
     assert Blanks.count(ast) == 2
   end
+
+  test "replaces whole line containing blank" do
+    ast = quote do
+      1 + 2
+      2 + ___
+    end
+
+    expected_result = quote do
+      1 + 2
+      true
+    end
+
+    actual_result = Blanks.replace_line(ast, fn(_) -> true end)
+
+    assert actual_result == expected_result
+  end
+
+  test "replacement fn can access line" do
+    ast = quote do
+      1 + 2
+      2 + ___
+    end
+
+    expected_result = quote do
+      1 + 2
+      some_fun(2 + ___)
+    end
+
+    actual_result = Blanks.replace_line(ast, fn(line) ->
+      quote do: some_fun(unquote(line))
+    end)
+
+    assert actual_result == expected_result
+  end
 end

test/blanks_test.exs

@@ -8,6 +8,6 @@ defmodule ExecuteTest do
   test "stops at the first failing koan" do
     {:failed, %{error: _, file: file, line: line}, SampleKoan, _name} = Execute.run_module(SampleKoan)
     assert file == 'test/support/sample_koan.ex'
-    assert line == 5
+    assert line == 4
   end
 end