Merge pull request #799 from mbj/refactor/test-selection

Change test selection to be cached

lib/mutant/env.rb

@@ -31,6 +31,16 @@ module Mutant
       )
     end
 
+    # The test selections
+    #
+    # @return Hash{Mutation => Enumerable<Test>}
+    def selections
+      subjects.map do |subject|
+        [subject, selector.call(subject)]
+      end.to_h
+    end
+    memoize :selections
+
   private
 
     # Kill mutation under isolation with integration
@@ -43,7 +53,7 @@ module Mutant
     # rubocop:disable MethodLength
     def run_mutation_tests(mutation)
       start = Timer.now
-      tests = selector.call(mutation.subject)
+      tests = selections.fetch(mutation.subject)
 
       config.isolation.call do
         mutation.insert(config.kernel)

lib/mutant/runner/sink.rb

@@ -43,7 +43,7 @@ module Mutant
         @subject_results[subject] = Result::Subject.new(
           subject:          subject,
           mutation_results: previous_mutation_results(subject) + [mutation_result],
-          tests:            mutation_result.test_result.tests
+          tests:            env.selections.fetch(subject)
         )
 
         self

spec/support/shared_context.rb

@@ -36,17 +36,26 @@ module SharedContext
   # rubocop:disable MethodLength
   # rubocop:disable AbcSize
   def setup_shared_context
-    let(:env)              { instance_double(Mutant::Env, config: config, subjects: [subject_a], mutations: mutations) }
     let(:job_a)           { Mutant::Parallel::Job.new(index: 0, payload: mutation_a) }
     let(:job_b)           { Mutant::Parallel::Job.new(index: 1, payload: mutation_b) }
-    let(:test_a)           { instance_double(Mutant::Test, identification: 'test-a')                                   }
-    let(:output)           { StringIO.new                                                                              }
-    let(:mutations)        { [mutation_a, mutation_b]                                                                  }
-    let(:mutation_a_node)  { s(:false)                                                                                 }
-    let(:mutation_b_node)  { s(:nil)                                                                                   }
-    let(:mutation_b)       { Mutant::Mutation::Evil.new(subject_a, mutation_b_node)                                    }
     let(:mutation_a)      { Mutant::Mutation::Evil.new(subject_a, mutation_a_node)   }
+    let(:mutation_a_node) { s(:false)                                                }
+    let(:mutation_b)      { Mutant::Mutation::Evil.new(subject_a, mutation_b_node)   }
+    let(:mutation_b_node) { s(:nil)                                                  }
+    let(:mutations)       { [mutation_a, mutation_b]                                 }
+    let(:output)          { StringIO.new                                             }
     let(:subject_a_node)  { s(:true)                                                 }
+    let(:test_a)          { instance_double(Mutant::Test, identification: 'test-a')  }
+
+    let(:env) do
+      instance_double(
+        Mutant::Env,
+        config:     config,
+        mutations:  mutations,
+        selections: { subject_a => [test_a] },
+        subjects:   [subject_a]
+      )
+    end
 
     let(:status) do
       Mutant::Parallel::Status.new(

spec/unit/mutant/env_spec.rb

@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 RSpec.describe Mutant::Env do
-  context '#kill' do
   let(:object) do
     described_class.new(
       actor_env:        Mutant::Actor::Env.new(Thread),
@@ -10,7 +9,7 @@ RSpec.describe Mutant::Env do
       matchable_scopes: [],
       mutations:        [],
       selector:         selector,
-        subjects:         [],
+      subjects:         [mutation_subject],
       parser:           Mutant::Parser.new
     )
   end
@@ -39,6 +38,15 @@ RSpec.describe Mutant::Env do
     )
   end
 
+  before do
+    expect(selector).to receive(:call)
+      .with(mutation_subject)
+      .and_return(tests)
+
+    allow(Mutant::Timer).to receive(:now).and_return(2.0, 3.0)
+  end
+
+  describe '#kill' do
     subject { object.kill(mutation) }
 
     shared_examples_for 'mutation kill' do
@@ -52,14 +60,6 @@ RSpec.describe Mutant::Env do
       end
     end
 
-    before do
-      expect(selector).to receive(:call)
-        .with(mutation_subject)
-        .and_return(tests)
-
-      allow(Mutant::Timer).to receive(:now).and_return(2.0, 3.0)
-    end
-
     context 'when isolation does not raise error' do
       let(:test_result) { instance_double(Mutant::Result::Test) }
 
@@ -99,4 +99,12 @@ RSpec.describe Mutant::Env do
       include_examples 'mutation kill'
     end
   end
+
+  describe '#selections' do
+    subject { object.selections }
+
+    it 'returns expected selections' do
+      expect(subject).to eql(mutation_subject => tests)
+    end
+  end
 end