generator: support example solutions in .meta/solutions

README.md

@@ -14,9 +14,19 @@ the language, so you're all set.
 
 The files for an exercise live in `exercises/<exercise_name>` (where
 `<exercise_name>` is the slug for the exercise, e.g. `clock` or
-`atbash-cipher`). An exercise has a test suite
-(`exercises/<exercise_name>/<exercise_name>_test.rb`) and an example solution
-(`exercises/<exercise_name>/example.rb`).
+`atbash-cipher`). All exercises have:
+
+* a test suite, `<exercise_name>_test.rb`
+* an example solution, `<exercise_name>.rb`, in `.meta/solutions`
+
+Tests with a test generator will also have:
+
+* a `.version`
+* the test generator, `<exercise_name>_cases.rb`, in `.meta/generator`
+
+A few tests have other custom files which are discussed below.
+
+### Canonical Data
 
 **Most exercises can be generated from shared inputs/outputs, called canonical
 data (see [Generated Test Suites](#generated-test-suites) below).** To find out
@@ -25,9 +35,9 @@ the [x-common repo](https://github.com/exercism/x-common/tree/master/exercises).
 
 ## Running the Tests
 
-Run the tests using `rake`, rather than `ruby path/to/the_test.rb`. `rake`
-knows to look for `example.rb` and to disable skips. Just tell `rake` the
-name of your problem and you are set:
+Run the tests using `rake`, rather than `ruby path/to/the_test.rb`. `rake` knows
+to look for the example solution and to disable skips. Just tell `rake` the name
+of your problem and you are set:
 
 ```sh
 rake test:clock
@@ -211,7 +221,7 @@ We have created a minimal set of guidelines for the testing files, which
 you can take advantage of by installing the `rubocop` gem.  It will use
 the configuration file located in the root folder, `.rubocop.yml`.  When
 you edit your code, you can simply run `rubocop -D`.  It will ignore
-your `example.rb`, but will gently suggest style for your test code.
+your example solution, but will gently suggest style for your test code.
 
 The `-D` option that is suggested is provided to give you the ability to
 easily ignore the Cops that you think should be ignored.  This is easily

lib/generator/files/track_files.rb

@@ -10,7 +10,7 @@ def tests_version
       end
 
       def example_solution
-        ExampleSolutionFile.new(filename: File.join(exercise_path, 'example.rb'))
+        ExampleSolutionFile.new(filename: File.join(exercise_path, example_file))
       end
 
       def minitest_tests
@@ -48,6 +48,18 @@ def tests_template_filename
         'test_template.erb'
       end
 
+      def example_file
+        File.exist?(File.join(exercise_path, example_filename)) ? example_filename : legacy_example_filename
+      end
+
+      def example_filename
+        File.join('.meta', 'solutions', "#{exercise_name}.rb")
+      end
+
+      def legacy_example_filename
+        'example.rb'
+      end
+
       def minitest_tests_filename
         "#{exercise_name.gsub(/[ -]/, '_')}_test.rb"
       end

lib/tasks/exercise.rb

@@ -23,7 +23,7 @@ def directory
   end
 
   def example_file
-    'example.rb'
+    File.exist?(example_filename) ? example_filename : legacy_example_filename
   end
 
   def testable_example_file
@@ -36,6 +36,14 @@ def test_file
 
   private
 
+  def example_filename
+    File.join('.meta', 'solutions', "#{name}.rb")
+  end
+
+  def legacy_example_filename
+    'example.rb'
+  end
+
   def base_file_name
     @_base_file_name ||= name.tr('-', '_')
   end

test/generator/files/track_files_test.rb

@@ -13,7 +13,7 @@ def initialize
           @paths = FixturePaths
           @exercise_name = 'alpha'
         end
-        attr_reader :paths, :exercise_name
+        attr_accessor :paths, :exercise_name
         include TrackFiles
       end
 
@@ -24,7 +24,15 @@ def test_tests_version
 
       def test_example_solution
         subject = TestTrackFiles.new
-        assert_instance_of ExampleSolutionFile, subject.example_solution
+        expected_filename = FixturePaths.track + '/exercises/alpha/.meta/solutions/alpha.rb'
+        assert_equal expected_filename, subject.example_solution.filename
+      end
+
+      def test_legacy_example_solution
+        subject = TestTrackFiles.new
+        subject.exercise_name = 'beta'
+        expected_filename = FixturePaths.track + '/exercises/beta/example.rb'
+        assert_equal expected_filename, subject.example_solution.filename
       end
 
       def test_minitest_tests
@@ -38,6 +46,7 @@ def test_tests_template
         assert_equal expected_filename, subject.tests_template.filename
       end
 
+
       class TestTrackFilesUseDefault
         def initialize
           @paths = FixturePaths
@@ -75,7 +84,9 @@ def save(content)
       end
 
       def test_update_version
-        subject = TestExampleSolutionFile.new(filename: 'test/fixtures/xruby/exercises/alpha/example.rb')
+        subject = TestExampleSolutionFile.new(
+          filename: 'test/fixtures/xruby/exercises/alpha/.meta/solutions/alpha.rb'
+        )
         assert_match(/VERSION = 2/, subject.update_version(2))
       end
     end

test/tasks/exercise_test.rb

@@ -31,6 +31,12 @@ def test_directory
   end
 
   def test_example_file
+    File.stub(:exist?, true) do
+      assert_equal '.meta/solutions/name.rb', Exercise.new('name').example_file
+    end
+  end
+
+  def test_legacy_example_file
     assert_equal 'example.rb', Exercise.new('').example_file
   end
 

test/tasks/exercise_tests_runner_legacy_test.rb

@@ -0,0 +1,64 @@
+require_relative '../test_helper'
+
+class FakeLegacyExercise
+  def name
+    'test'
+  end
+
+  alias :to_s :name
+
+  def directory
+    'test/.'
+  end
+
+  def example_file
+    'example.rb'
+  end
+
+  def testable_example_file
+    'test.rb'
+  end
+
+  def test_file
+    'test_test.rb'
+  end
+end
+
+class ExerciseTestsRunnerLegacyTest < Minitest::Test
+  def test_run
+    Dir.stub :mktmpdir, nil, 'dir' do
+      cp_mock = Minitest::Mock.new.expect(:call, nil, ['test/.', 'dir'])
+
+      mv_mock = Minitest::Mock.new.expect(
+        :call,
+        nil,
+        ['dir/example.rb', 'dir/test.rb'],
+      )
+
+      ruby_mock = Minitest::Mock.new.expect(
+        :call,
+        nil,
+        ['-I lib -r disable_skip.rb dir/test_test.rb -p'],
+      )
+
+      FileUtils.stub :cp_r, cp_mock do
+        FileUtils.stub :mv, mv_mock do
+          runner = ExerciseTestsRunner.new(
+            exercise: FakeLegacyExercise.new,
+            test_options: '-p',
+          )
+
+          runner.stub :ruby, ruby_mock do
+            assert_output "\n\n#{'-'*64}\nrunning tests for: test\n" do
+              runner.run
+            end
+          end
+
+          cp_mock.verify
+          mv_mock.verify
+          ruby_mock.verify
+        end
+      end
+    end
+  end
+end

test/tasks/exercise_tests_runner_test.rb

@@ -12,7 +12,7 @@ def directory
   end
 
   def example_file
-    'example.rb'
+    '.meta/solutions/test.rb'
   end
 
   def testable_example_file
@@ -32,7 +32,7 @@ def test_run
       mv_mock = Minitest::Mock.new.expect(
         :call,
         nil,
-        ['dir/example.rb', 'dir/test.rb'],
+        ['dir/.meta/solutions/test.rb', 'dir/test.rb'],
       )
 
       ruby_mock = Minitest::Mock.new.expect(