Merge pull request #568 from hilary/auto_extract_cases

Provides a common implementation of the code that extracts the individual test cases from a problem's `canonical_data.json` file, and removes support for the 'proc' based procedure previously used in the 'lib/<problem>_cases.rb' files.

Author: Insti

lib/generator/case_values.rb

@@ -0,0 +1,25 @@
+module Generator
+  module CaseValues
+    class Extractor
+      def initialize(case_class:)
+        @case_class = case_class
+      end
+
+      def cases(exercise_data)
+        extract_test_cases(
+          data: JSON.parse(exercise_data)['cases']
+        ).map.with_index do |test, index|
+          @case_class.new(test.merge('index' => index))
+        end
+      end
+
+      private
+
+      def extract_test_cases(data:)
+        data.flat_map do |entry|
+          entry.key?('cases') ? extract_test_cases(data: entry['cases']) : entry
+        end
+      end
+    end
+  end
+end

lib/generator/files/track_files.rb

@@ -14,13 +14,18 @@ def filename(exercise_name)
         "#{exercise_name.tr('-', '_')}_cases"
       end
 
-      def proc_name(exercise_name)
-        filename(exercise_name).split('_').map(&:capitalize).join
+      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

lib/generator/template_values.rb

@@ -16,23 +16,28 @@ def get_binding
 
   module TemplateValuesFactory
     def template_values
-      require cases_require_name
-
       TemplateValues.new(
         abbreviated_commit_hash: canonical_data.abbreviated_commit_hash,
         version: version,
-        test_cases: test_cases_proc.call(canonical_data.to_s)
+        test_cases: extract
       )
     end
 
     private
 
-    def cases_require_name
-      Files::GeneratorCases.filename(exercise_name)
+    def extract
+      load cases_load_name
+      extractor.cases(canonical_data.to_s)
+    end
+
+    def extractor
+        CaseValues::Extractor.new(
+          case_class: Object.const_get(Files::GeneratorCases.class_name(exercise_name))
+        )
     end
 
-    def test_cases_proc
-      Object.const_get(Files::GeneratorCases.proc_name(exercise_name))
+    def cases_load_name
+      Files::GeneratorCases.load_filename(paths.track, exercise_name)
     end
   end
 end

test/fixtures/metadata/exercises/complex/canonical-data.json

@@ -0,0 +1,45 @@
+{
+  "exercise": "beer-song",
+  "version": "1.0.0",
+  "cases": [
+    {
+      "description": "verse",
+      "cases": [
+        {
+          "description": "single verse",
+          "cases": [
+            {
+              "description": "first generic verse",
+              "property": "verse",
+              "number": 99,
+              "expected": "99 bottles of beer on the wall, YAAAR"
+            },
+            {
+              "description": "last generic verse",
+              "property": "verse",
+              "number": 3,
+              "expected": "3 bottles of beer on the wall, YAAAR"
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "lyrics",
+      "cases": [
+        {
+          "description": "multiple verses",
+          "cases": [
+            {
+              "description": "first two verses",
+              "property": "verses",
+              "beginning": 99,
+              "end": 98,
+              "expected": "99 bottles of beer on the wall, YAR, PIRATES CAN'T COUNT"
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/fixtures/xruby/lib/beta_cases.rb

@@ -0,0 +1,7 @@
+require 'exercise_cases'
+
+class BetaCase < ExerciseCase
+  def workload
+    assert_equal { "Beta.call('#{input}')" }
+  end
+end

test/generator/case_values_test.rb

@@ -0,0 +1,30 @@
+require_relative '../test_helper'
+
+class ComplexCase < ExerciseCase
+  def workload
+    assert { Complex.foo(bar) }
+  end
+end
+
+module Generator
+  module CaseValues
+    class ExtractorTest < Minitest::Test
+      def test_multi_level_auto_extraction
+        canonical_data = File.read('test/fixtures/metadata/exercises/complex/canonical-data.json')
+        cases = Extractor.new(
+          case_class: ComplexCase,
+        ).cases(canonical_data)
+
+        expected = [
+          ComplexCase.new(description: 'first generic verse', property: 'verse', number: 99,
+                          expected: '99 bottles of beer on the wall, YAAAR', index: 0),
+          ComplexCase.new(description: 'last generic verse', property: 'verse', number: 3,
+                          expected: '3 bottles of beer on the wall, YAAAR', index: 1),
+          ComplexCase.new(description: 'first two verses', property: 'verses', beginning: 99, end: 98,
+                          expected: "99 bottles of beer on the wall, YAR, PIRATES CAN'T COUNT", index: 2)
+        ]
+        assert_equal expected, cases
+      end
+    end
+  end
+end

test/generator/files/track_files_test.rb

@@ -25,9 +25,8 @@ def test_filename
         assert_equal 'two_parter_cases', GeneratorCases.filename(exercise_name)
       end
 
-      def test_proc_name
-        exercise_name = 'two-parter'
-        assert_equal 'TwoParterCases', GeneratorCases.proc_name(exercise_name)
+      def test_class_name
+        assert_equal 'TwoParterCase', GeneratorCases.class_name('two-parter')
       end
     end
 

test/generator/template_values_test.rb

@@ -43,17 +43,58 @@ def canonical_data
         mock_canonical_data
       end
 
+      def paths
+        mock_paths = Minitest::Mock.new
+        mock_paths.expect :track, 'test/fixtures/xruby'
+        mock_paths
+      end
+
       include TemplateValuesFactory
     end
 
-    def test_template_values
-      $LOAD_PATH.unshift 'test/fixtures/xruby/lib'
+    class ClassBasedTestTemplateValuesFactory
+      def exercise_name
+        'beta'
+      end
+
+      def version
+        2
+      end
+
+      def canonical_data
+        mock_canonical_data = Minitest::Mock.new
+        mock_canonical_data.expect :abbreviated_commit_hash, nil
+        mock_canonical_data.expect :to_s, '{"cases":[]}'
+        mock_canonical_data
+      end
+
+      def paths
+        mock_paths = Minitest::Mock.new
+        mock_paths.expect :track, 'test/fixtures/xruby'
+        mock_paths
+      end
+
+      include TemplateValuesFactory
+    end
+
+    def test_template_values_from_class
+      subject = ClassBasedTestTemplateValuesFactory.new
+      assert_instance_of TemplateValues, subject.template_values
+    end
+
+    def test_template_values_loads_problem_case_classes
       subject = TestTemplateValuesFactory.new
       assert_instance_of TemplateValues, subject.template_values
+      assert Object.const_defined?(:AlphaCase)
+      assert Object.const_defined?(:AlphaCases)
     end
 
     def teardown
-      $LOAD_PATH.delete 'test/fixtures/xruby/lib'
+      [:AlphaCase, :AlphaCases].each do |classname|
+        if Object.const_defined?(classname)
+          Object.send(:remove_const, classname)
+        end
+      end
     end
   end
 end