Add test minitest integration

[fix #92]

config/flay.yml

@@ -1,3 +1,3 @@
 ---
 threshold: 16
-total_score: 1364
+total_score: 1395

lib/mutant/integration/minitest.rb

@@ -0,0 +1,174 @@
+# frozen_string_literal: true
+
+require 'minitest'
+require 'mutant/minitest/coverage'
+
+module Minitest
+  # Prevent autorun from running tests when the VM closes
+  #
+  # Mutant needs control about the exit status of the VM and
+  # the moment of test execution
+  #
+  # @api private
+  #
+  # @return [nil]
+  def self.autorun; end
+end # Minitest
+
+module Mutant
+  class Integration
+    # Minitest integration
+    class Minitest < self
+      TEST_FILE_PATTERN     = './test/**/{test_*,*_test}.rb'
+      IDENTIFICATION_FORMAT = 'minitest:%s#%s'
+
+      private_constant(*constants(false))
+
+      # Compose a runnable with test method
+      #
+      # This looks actually like a missing object on minitest implementation.
+      class TestCase
+        include Adamantium, Concord.new(:klass, :test_method)
+
+        # Identification string
+        #
+        # @return [String]
+        def identification
+          IDENTIFICATION_FORMAT % [klass, test_method]
+        end
+        memoize :identification
+
+        # Run test case
+        #
+        # @param [Object] reporter
+        #
+        # @return [Boolean]
+        def call(reporter)
+          ::Minitest::Runnable.run_one_method(klass, test_method, reporter)
+          reporter.passed?
+        end
+
+        # Cover expression syntaxes
+        #
+        # @return [String, nil]
+        def expression_syntax
+          klass.resolve_cover_expression
+        end
+
+      end # TestCase
+
+      private_constant(*constants(false))
+
+      # Setup integration
+      #
+      # @return [self]
+      def setup
+        Pathname.glob(TEST_FILE_PATTERN)
+          .map(&:to_s)
+          .each(&method(:require))
+
+        self
+      end
+
+      # Call test integration
+      #
+      # @param [Array<Tests>] tests
+      #
+      # @return [Result::Test]
+      #
+      # rubocop:disable MethodLength
+      #
+      # ignore :reek:TooManyStatements
+      def call(tests)
+        test_cases = tests.map(&all_tests_index.method(:fetch))
+        output     = StringIO.new
+        start      = Time.now
+
+        reporter = ::Minitest::SummaryReporter.new(output)
+
+        reporter.start
+
+        test_cases.each do |test|
+          break unless test.call(reporter)
+        end
+
+        output.rewind
+
+        Result::Test.new(
+          passed:  reporter.passed?,
+          tests:   tests,
+          output:  output.read,
+          runtime: Time.now - start
+        )
+      end
+
+      # All tests exposed by this integration
+      #
+      # @return [Array<Test>]
+      def all_tests
+        all_tests_index.keys
+      end
+      memoize :all_tests
+
+    private
+
+      # The index of all tests to runnable test cases
+      #
+      # @return [Hash<Test,TestCase>]
+      def all_tests_index
+        all_test_cases.each_with_object({}) do |test_case, index|
+          index[construct_test(test_case)] = test_case
+        end
+      end
+      memoize :all_tests_index
+
+      # Construct test from test case
+      #
+      # @param [TestCase]
+      #
+      # @return [Test]
+      def construct_test(test_case)
+        Test.new(
+          id:         test_case.identification,
+          expression: config.expression_parser.call(test_case.expression_syntax)
+        )
+      end
+
+      # All minitest test cases
+      #
+      # Intentional utility method.
+      #
+      # @return [Array<TestCase>]
+      def all_test_cases
+        ::Minitest::Runnable
+          .runnables
+          .select(&method(:allow_runnable?))
+          .flat_map(&method(:test_case))
+      end
+
+      # Test if runnable qualifies for mutation testing
+      #
+      # @param [Class]
+      #
+      # @return [Bool]
+      #
+      # ignore :reek:UtilityFunction
+      def allow_runnable?(klass)
+        !klass.equal?(::Minitest::Runnable) && klass.resolve_cover_expression
+      end
+
+      # Turn a minitest runnable into its test cases
+      #
+      # Intentional utility method.
+      #
+      # @param [Object] runnable
+      #
+      # @return [Array<TestCase>]
+      #
+      # ignore :reek:UtilityFunction
+      def test_case(runnable)
+        runnable.runnable_methods.map { |method| TestCase.new(runnable, method) }
+      end
+    end # Minitest
+  end # Integration
+end # Mutant

lib/mutant/minitest/coverage.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+require 'minitest'
+
+module Mutant
+  module Minitest
+    module Coverage
+      # Setup coverage declaration for current class
+      #
+      # @param [String]
+      #
+      # @example
+      #
+      #   class MyTest < MiniTest::Test
+      #     cover 'MyCode*'
+      #
+      #     def test_some_stuff
+      #     end
+      #   end
+      #
+      # @api public
+      def cover(expression)
+        fail "#{self} already declares to cover: #{@covers}" if @covers
+
+        @cover_expression = expression
+      end
+
+      # Effective coverage expression
+      #
+      # @return [String, nil]
+      #
+      # @api private
+      def resolve_cover_expression
+        return @cover_expression if defined?(@cover_expression)
+
+        try_superclass_cover_expression
+      end
+
+    private
+
+      # Attempt to resolve superclass cover expressio
+      #
+      # @return [String, nil]
+      #
+      # @api private
+      def try_superclass_cover_expression
+        return if superclass.equal?(::Minitest::Runnable)
+
+        superclass.resolve_cover_expression
+      end
+
+    end # Coverage
+  end # Minitest
+end # Mutant
+
+Minitest::Test.extend(Mutant::Minitest::Coverage)

mutant-minitest.gemspec

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require File.expand_path('lib/mutant/version', __dir__)
+
+Gem::Specification.new do |gem|
+  gem.name        = 'mutant-minitest'
+  gem.version     = Mutant::VERSION.dup
+  gem.authors     = ['Markus Schirp']
+  gem.email       = %w[mbj@schirp-dso.com]
+  gem.description = 'Minitest integration for mutant'
+  gem.summary     = gem.description
+  gem.homepage    = 'https://github.com/mbj/mutant'
+  gem.license     = 'MIT'
+
+  gem.require_paths    = %w[lib]
+  gem.files            = `git ls-files -- lib/mutant/{minitest,/integration/minitest.rb}`.split("\n")
+  gem.test_files       = `git ls-files -- spec/integration/mutant/minitest.rb`.split("\n")
+  gem.extra_rdoc_files = %w[LICENSE]
+
+  gem.add_runtime_dependency('minitest', '~> 5.11')
+  gem.add_runtime_dependency('mutant',   "~> #{gem.version}")
+end

mutant.gemspec

@@ -14,9 +14,9 @@ Gem::Specification.new do |gem|
 
   gem.require_paths = %w[lib]
 
-  mutant_integration_files = `git ls-files -- lib/mutant/integration/*.rb`.split("\n")
+  exclusion = `git ls-files -- lib/mutant/{minitest,integration}`.split("\n")
 
-  gem.files            = `git ls-files`.split("\n") - mutant_integration_files
+  gem.files            = `git ls-files`.split("\n") - exclusion
   gem.test_files       = `git ls-files -- spec/{unit,integration}`.split("\n")
   gem.extra_rdoc_files = %w[LICENSE]
   gem.executables      = %w[mutant]

spec/integration/mutant/minitest_spec.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+RSpec.describe 'minitest integration', mutant: false do
+
+  let(:base_cmd) { 'bundle exec mutant -I test -I lib --require test_app --use minitest' }
+
+  let(:gemfile) { 'Gemfile.minitest' }
+
+  it_behaves_like 'framework integration'
+end

spec/integrations.yml

@@ -41,6 +41,16 @@
   mutation_generation: true
   expected_errors: {}
   exclude: []
+- name: auom
+  namespace: AUOM
+  repo_uri: 'https://github.com/mbj/auom.git'
+  repo_ref: 'origin/add/minitest'
+  ruby_glob_pattern: '**/*.rb'
+  integration: minitest
+  mutation_coverage: true
+  mutation_generation: true
+  expected_errors: {}
+  exclude: []
 - name: axiom
   namespace: Axiom
   repo_uri: 'https://github.com/dkubb/axiom.git'

spec/support/corpus.rb

@@ -167,6 +167,7 @@ module MutantSpec
         repo_path.join('Gemfile').open('a') do |file|
           file << "gem 'mutant', path: '#{relative}'\n"
           file << "gem 'mutant-rspec', path: '#{relative}'\n"
+          file << "gem 'mutant-minitest', path: '#{relative}'\n"
           file << "eval_gemfile File.expand_path('#{relative.join('Gemfile.shared')}')\n"
         end
         lockfile = repo_path.join('Gemfile.lock')

test_app/Gemfile.minitest

@@ -0,0 +1,6 @@
+source 'https://rubygems.org'
+
+gem 'minitest',        '~> 5.11'
+gem 'mutant',          path: '../'
+gem 'mutant-minitest', path: '../'
+gem 'adamantium'

test_app/test/unit/test_app/literal_test.rb

@@ -0,0 +1,16 @@
+require 'minitest/autorun'
+require 'mutant/minitest/coverage'
+
+class LiteralTest < Minitest::Test
+  cover 'TestApp::Literal*'
+
+  def test_command
+    object = ::TestApp::Literal.new
+
+    assert_equal(object, object.command('x'))
+  end
+
+  def test_string
+    assert_equal('string', ::TestApp::Literal.new.string)
+  end
+end