generators: Default test template

README.md

@@ -64,7 +64,7 @@ Note that flags which have an attached value, like above, must take the form
 
 ### Generated Test Suites
 
-If you find an `example.tt` file in a problem directory, then the test suite is
+If you find a `<problem_name>_cases.rb` file in `lib/`, then the test suite is
 generated from shared data, which can be found in the exercise definition in the [x-common][]
 repository.
 
@@ -94,7 +94,8 @@ bin/generate $PROBLEM
 
 #### Changing a Generated Exercise
 
-The `$PROBLEM/$PROBLEM_test.rb` will never be edited directly.
+Do not edit `$PROBLEM/$PROBLEM_test.rb`. Any changes you make will be overwritten when
+the file is generated the next time.
 
 There are two reasons why a test suite might change:
 
@@ -114,23 +115,14 @@ the exercise, which lives in the x-common repository.
 This change will need to be submitted as a pull request to the x-common repository. This pull
 request needs to be merged before you can regenerate the exercise.
 
-Changes that don't have to do directly with the test inputs and outputs, will
-most likely be made to `lib/$PROBLEM_cases.rb` but may also be made to
-`exercises/$PROBLEM/example.tt`. Then you can regenerate the exercise with
+Changes that don't have to do directly with the test inputs and outputs should
+be made to `lib/$PROBLEM_cases.rb`. Then you can regenerate the exercise with
 `bin/generate $PROBLEM`.
 
 #### Implementing a Generator
 
-You will need to implement two files and a directory to create a generator:
-
-1. `lib/$PROBLEM_cases.rb` - the logic for turning the data into tests.
-1. `exercises/$PROBLEM/example.tt` - the Erb template for the test file, `$PROBLEM_test.rb`.
-1. `exercises/$PROBLEM/.meta/` - metadata directory, currently contains version file
-
-You will not need to touch the top-level script, `bin/generate`.
-
-The `bin/generate` command relies on some common logic implemented in `lib/generator.rb`.
-You probably won't need to touch that, either.
+You will need to write code to produce the code that goes inside the test methods. Your
+code will live in `lib/$PROBLEM_cases.rb`.
 
 `lib/$PROBLEM_cases.rb` contains a derived class of `ExerciseCase` (in `lib/generator/exercise_cases.rb`)
 which wraps the JSON for a single test case. The default version looks something like this:
@@ -149,42 +141,24 @@ end
 Instead of `ProblemName` use the CamelCased name of the actual problem. This is important, since
 the generator script will infer the name of the class from the argument that is passed.
 
-This class must provide the methods used by `example.tt`. The base class provides methods
+This class must provide the methods used by `lib/generator/test_template.erb`. The base class provides methods
 for the default template for everything except `workload`.
 
 `workload` generates the code for the body of a test, including the assertion
 and any setup required. The base class provides a variety of assertion and
 helper methods. Beyond that, you can implement any helper methods that you need
 as private methods in your derived class. See below for more information about [the intention of workload](#workload-philosophy)
 
-Finally, you need to create a text template, `example.tt`, as the bases for the test suite.
+If you really must add additional logic to the view template, you can use a custom
+template. Copy `lib/generator/test_template.erb` to your exercise directory, name it
+`exercise.tt`, and customize.
 
-Start with the following boilerplate, and adjust as necessary. Remember, however, to strive
-to keep logic out of views.
+You will not need to touch the top-level script, `bin/generate`.
 
-```
-#!/usr/bin/env ruby
-gem 'minitest', '>= 5.0.0'
-require 'minitest/autorun'
-require_relative '$PROBLEM'
-
-# Common test data version: <%= abbreviated_commit_hash %>
-class ProblemNameTest < Minitest::Test
-<% test_cases.each do |test_case| %>
-  def <%= test_case.name %>
-    <%= test_case.skipped %>
-    <%= test_case.workload %>
-  end
+The `bin/generate` command relies on some common logic implemented in `lib/generator.rb`.
+You won't need to touch that, either.
 
-<% end %>
-<%= IO.read(XRUBY_LIB + '/bookkeeping.md') %>
 
-  def test_bookkeeping
-    skip
-    assert_equal <%= version %>, BookKeeping::VERSION
-  end
-end
-```
 ### Workload philosophy.
 
 Prioritize educational value over expert comprehension and make sure that

lib/generator/files/generator_cases.rb

@@ -0,0 +1,29 @@
+module Generator
+  module Files
+    module GeneratorCases
+      module_function
+
+      def available(track_path)
+        generator_glob = File.join(track_path, 'lib', '*_cases.rb')
+        Dir[generator_glob].sort.map { |filename| exercise_name(filename) }
+      end
+
+      def filename(exercise_name)
+        "#{exercise_name.tr('-', '_')}_cases"
+      end
+
+      def class_name(exercise_name)
+        filename(exercise_name)[0..-2].split('_').map(&:capitalize).join
+      end
+
+      def exercise_name(filename)
+        %r{([^/]*)_cases\.rb$}.match(filename).captures[0].tr('_', '-')
+      end
+
+      def load_filename(track_path, exercise_name)
+        path = File.join(track_path, 'lib')
+        "%s/%s.rb" % [ path, filename(exercise_name) ]
+      end
+    end
+  end
+end

lib/generator/files/track_files.rb

@@ -2,32 +2,6 @@
 
 module Generator
   module Files
-    module GeneratorCases
-      module_function
-
-      def available(track_path)
-        generator_glob = File.join(track_path, 'lib', '*_cases.rb')
-        Dir[generator_glob].sort.map { |filename| exercise_name(filename) }
-      end
-
-      def filename(exercise_name)
-        "#{exercise_name.tr('-', '_')}_cases"
-      end
-
-      def class_name(exercise_name)
-        filename(exercise_name)[0..-2].split('_').map(&:capitalize).join
-      end
-
-      def exercise_name(filename)
-        %r{([^/]*)_cases\.rb$}.match(filename).captures[0].tr('_', '-')
-      end
-
-      def load_filename(track_path, exercise_name)
-        path = File.join(track_path, 'lib')
-        "%s/%s.rb" % [ path, filename(exercise_name) ]
-      end
-    end
-
     module TrackFiles
       include Exercise
 
@@ -44,7 +18,7 @@ def minitest_tests
       end
 
       def tests_template
-        TestsTemplateFile.new(filename: File.join(exercise_path, 'example.tt'))
+        TestsTemplateFile.new(filename: tests_template_filename)
       end
 
       private
@@ -53,6 +27,16 @@ def exercise_path
         File.join(paths.track, 'exercises', exercise_name)
       end
 
+      # this method contains a LOT of magic text
+      def tests_template_filename
+        File.exist?(track_tests_template_filename) ? track_tests_template_filename :
+          File.join(paths.track, 'lib', 'generator', 'test_template.erb')
+      end
+
+      def track_tests_template_filename
+        File.join(exercise_path, 'example.tt')
+      end
+
       def minitest_tests_filename
         "#{exercise_name.gsub(/[ -]/, '_')}_test.rb"
       end

lib/generator/template_values.rb

@@ -1,11 +1,14 @@
+require 'forwardable'
+
 module Generator
   # Contains methods accessible to the ERB template
   class TemplateValues
-    attr_reader :abbreviated_commit_hash, :version, :test_cases
+    attr_reader :metadata, :test_cases
+    extend Forwardable
+    def_delegators :@metadata, :abbreviated_commit_hash, :version, :exercise_name, :exercise_name_camel
 
-    def initialize(abbreviated_commit_hash:, version:, test_cases:)
-      @abbreviated_commit_hash = abbreviated_commit_hash
-      @version = version
+    def initialize(metadata:, test_cases:)
+      @metadata = metadata
       @test_cases = test_cases
     end
 
@@ -14,11 +17,28 @@ def get_binding
     end
   end
 
+  class TemplateMetadata
+    attr_reader :abbreviated_commit_hash, :version, :exercise_name
+
+    def initialize(abbreviated_commit_hash:, version:, exercise_name:)
+      @abbreviated_commit_hash = abbreviated_commit_hash
+      @version = version
+      @exercise_name = exercise_name ? exercise_name.tr('-_', '_') : ''
+    end
+
+    def exercise_name_camel
+      exercise_name.split(/[-_]/).map(&:capitalize).join
+    end
+  end
+
   module TemplateValuesFactory
     def template_values
       TemplateValues.new(
-        abbreviated_commit_hash: canonical_data.abbreviated_commit_hash,
-        version: version,
+        metadata: TemplateMetadata.new(
+          abbreviated_commit_hash: canonical_data.abbreviated_commit_hash,
+          version: version,
+          exercise_name: exercise_name
+        ),
         test_cases: extract
       )
     end

lib/generator/test_template.erb

@@ -0,0 +1,21 @@
+#!/usr/bin/env ruby
+gem 'minitest', '>= 5.0.0'
+require 'minitest/autorun'
+require_relative '<%= metadata.exercise_name %>'
+
+# Common test data version: <%= metadata.abbreviated_commit_hash %>
+class <%= metadata.exercise_name_camel %>Test < Minitest::Test
+<% test_cases.each do |test_case| %>
+  def <%= test_case.name %>
+    <%= test_case.skipped %>
+    <%= test_case.workload %>
+  end
+
+<% end %>
+<%= IO.read(XRUBY_LIB + '/bookkeeping.md') %>
+
+  def test_bookkeeping
+    skip
+    assert_equal <%= metadata.version %>, BookKeeping::VERSION
+  end
+end

test/fixtures/xruby/lib/generator/test_template.erb

@@ -0,0 +1,21 @@
+#!/usr/bin/env ruby
+gem 'minitest', '>= 5.0.0'
+require 'minitest/autorun'
+require_relative '<%= metadata.exercise_name %>'
+
+# Common test data version: <%= metadata.abbreviated_commit_hash %>
+class <%= metadata.exercise_name_camel %>Test < Minitest::Test
+<% test_cases.each do |test_case| %>
+  def <%= test_case.name %>
+    <%= test_case.skipped %>
+    <%= test_case.workload %>
+  end
+
+<% end %>
+<%= IO.read(XRUBY_LIB + '/bookkeeping.md') %>
+
+  def test_bookkeeping
+    skip
+    assert_equal <%= metadata.version %>, BookKeeping::VERSION
+  end
+end

test/generator/files/generate_cases_test.rb

@@ -0,0 +1,33 @@
+require_relative '../../test_helper.rb'
+
+module Generator
+  module Files
+    class GeneratorCasesTest < Minitest::Test
+      def test_no_cases_found
+        track_path = 'test/fixtures/nonexistant'
+        assert_equal [], GeneratorCases.available(track_path)
+      end
+
+      def test_cases_found
+        track_path = 'test/fixtures/xruby'
+        assert_equal %w(alpha beta), GeneratorCases.available(track_path).sort
+      end
+
+      def test_available_returns_exercise_names
+        track_path = 'test/fixtures/xruby'
+        Dir.stub :[], %w(/alpha_cases.rb hy_phen_ated_cases.rb) do
+          assert_equal %w(alpha hy-phen-ated), GeneratorCases.available(track_path)
+        end
+      end
+
+      def test_filename
+        exercise_name = 'two-parter'
+        assert_equal 'two_parter_cases', GeneratorCases.filename(exercise_name)
+      end
+
+      def test_class_name
+        assert_equal 'TwoParterCase', GeneratorCases.class_name('two-parter')
+      end
+    end
+  end
+end

test/generator/files/track_files_test.rb

@@ -2,34 +2,6 @@
 
 module Generator
   module Files
-    class GeneratorCasesTest < Minitest::Test
-      def test_no_cases_found
-        track_path = 'test/fixtures/nonexistant'
-        assert_equal [], GeneratorCases.available(track_path)
-      end
-
-      def test_cases_found
-        track_path = 'test/fixtures/xruby'
-        assert_equal %w(alpha beta), GeneratorCases.available(track_path).sort
-      end
-
-      def test_available_returns_exercise_names
-        track_path = 'test/fixtures/xruby'
-        Dir.stub :[], %w(/alpha_cases.rb hy_phen_ated_cases.rb) do
-          assert_equal %w(alpha hy-phen-ated), GeneratorCases.available(track_path)
-        end
-      end
-
-      def test_filename
-        exercise_name = 'two-parter'
-        assert_equal 'two_parter_cases', GeneratorCases.filename(exercise_name)
-      end
-
-      def test_class_name
-        assert_equal 'TwoParterCase', GeneratorCases.class_name('two-parter')
-      end
-    end
-
     class TrackFilesTest < Minitest::Test
       FixturePaths = Paths.new(
         metadata: 'test/fixtures/metadata',
@@ -64,6 +36,20 @@ def test_tests_template
         subject = TestTrackFiles.new
         assert_instance_of TestsTemplateFile, subject.tests_template
       end
+
+      class TestTrackFilesUseDefault
+        def initialize
+          @paths = FixturePaths
+          @exercise_name = 'notemplate'
+        end
+        attr_reader :paths, :exercise_name
+        include TrackFiles
+      end
+
+      def test_default_tests_template
+        subject = TestTrackFiles.new
+        assert_instance_of TestsTemplateFile, subject.tests_template
+      end
     end
 
     class TestsVersionFileTest < Minitest::Test