Format match? failures more elegantly

[#144]

lib/display/failure.ex

@@ -26,6 +26,12 @@ defmodule Display.Failure do
   defp format_inequality(message, %{left: @no_value, right: @no_value}) do
     message
   end
+  defp format_inequality(message, %{left: @no_value, right: match_value}) do
+    """
+    #{message}
+    value does not match: #{match_value |> inspect |> Paint.yellow}
+    """
+  end
   defp format_inequality(message, %{left: left, right: right}) do
     """
     #{message}

test/display/failure_test.exs

@@ -25,6 +25,18 @@ defmodule FailureTests do
                                             right: :wat
                                             """
   end
+
+  test "match failure" do
+    error = error(%ExUnit.AssertionError{expr: quote(do: match?(:lol,:wat)), right: :wat})
+
+    assert Failure.format_failure(error) == """
+                                            Assertion failed in some_file.ex:42
+                                            match?(:lol, :wat)
+
+                                            value does not match: :wat
+                                            """
+  end
+
   defp error(error) do
     %{
       error: error,