Extract pure executor of koans

test/executor_test.exs

@@ -0,0 +1,13 @@
+defmodule RunnerTest do
+  use ExUnit.Case
+
+  test "passes a koan" do
+    assert :passed == Execute.run_module(PassingKoan)
+  end
+
+  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
+  end
+end