Always build valid result objects

* Before Mutant::Expression was not marshallable resulting in the need
  to build "partial" result objects from killforks.
* Fixes an adjacent bug in spec selection

lib/mutant/env.rb

@@ -64,7 +64,7 @@ module Mutant
       config.isolation.call do
         mutation.insert
         config.integration.call(tests)
-      end.update(tests: tests)
+      end
     rescue Isolation::Error => error
       Result::Test.new(
         tests:   tests,

lib/mutant/env/bootstrap.rb

@@ -66,7 +66,7 @@ module Mutant
           cache:            cache,
           subjects:         subjects,
           matchable_scopes: matchable_scopes,
-          selector:         Selector::Expression.new(config.integration.all_tests),
+          selector:         Selector::Expression.new(config.integration),
           mutations:        subjects.flat_map(&:mutations)
         )
       end

lib/mutant/expression.rb

@@ -37,6 +37,33 @@ module Mutant
       @inspect = format(INSPECT_FORMAT, syntax)
     end
 
+    # Return marshallable representation
+    #
+    # FIXME: Remove the need for this.
+    #
+    #   Refactoring Expression objects not to reference a MatchData instance.
+    #   This will make this hack unneeded.
+    #
+    # @return [String]
+    #
+    # @api private
+    #
+    def _dump(_level)
+      syntax
+    end
+
+    # Load serializable representation
+    #
+    # @return [String]
+    #
+    # @return [Expression]
+    #
+    # @api private
+    #
+    def self._load(syntax)
+      parse(syntax)
+    end
+
     # Return inspection
     #
     # @return [String]

lib/mutant/integration/rspec.rb

@@ -54,7 +54,7 @@ module Mutant
         passed = @runner.run_specs(RSpec.world.ordered_example_groups).equal?(EXIT_SUCCESS)
         @output.rewind
         Result::Test.new(
-          tests:    nil,
+          tests:    tests,
           output:   @output.read,
           runtime:  Time.now - start,
           passed:   passed

lib/mutant/reporter/cli/printer.rb

@@ -295,7 +295,7 @@ module Mutant
         # Subject report printer
         class SubjectResult < self
 
-          delegate :subject, :failed_mutations
+          delegate :subject, :failed_mutations, :tests
 
           # Run report printer
           #
@@ -305,7 +305,7 @@ module Mutant
           #
           def run
             status(subject.identification)
-            subject.tests.each do |test|
+            tests.each do |test|
               puts("- #{test.identification}")
             end
             visit_collection(MutationResult, object.alive_mutation_results)

lib/mutant/result.rb

@@ -147,7 +147,7 @@ module Mutant
 
     # Subject result
     class Subject
-      include Coverage, Result, Anima.new(:subject, :mutation_results)
+      include Coverage, Result, Anima.new(:subject, :tests, :mutation_results)
 
       sum :killtime, :mutation_results
       sum :runtime,  :mutation_results

lib/mutant/runner/sink.rb

@@ -46,6 +46,7 @@ module Mutant
           @subject_results = Hash.new do |_hash, subject|
             Result::Subject.new(
               subject:          subject,
+              tests:            [],
               mutation_results: []
             )
           end
@@ -85,7 +86,8 @@ module Mutant
           original = @subject_results[mutation.subject]
 
           @subject_results[mutation.subject] = original.update(
-            mutation_results: (original.mutation_results.dup << mutation_result)
+            mutation_results: (original.mutation_results.dup << mutation_result),
+            tests:            mutation_result.test_result.tests
           )
 
           self

lib/mutant/selector/expression.rb

@@ -2,7 +2,7 @@ module Mutant
   class Selector
     # Expression based test selector
     class Expression < self
-      include Concord.new(:tests)
+      include Concord.new(:integration)
 
       # Return tests for subject
       #
@@ -14,7 +14,7 @@ module Mutant
       #
       def call(subject)
         subject.match_expressions.each do |match_expression|
-          subject_tests = tests.select do |test|
+          subject_tests = integration.all_tests.select do |test|
             match_expression.prefix?(test.expression)
           end
           return subject_tests if subject_tests.any?

spec/support/shared_context.rb

@@ -111,6 +111,7 @@ module SharedContext
     let(:subject_a_result) do
       Mutant::Result::Subject.new(
         subject:          subject_a,
+        tests:            [test_a],
         mutation_results: [mutation_a_result, mutation_b_result]
       )
     end

spec/unit/mutant/env/boostrap_spec.rb

@@ -16,7 +16,7 @@ RSpec.describe Mutant::Env::Bootstrap do
       matchable_scopes: [],
       mutations:        [],
       config:           config,
-      selector:         Mutant::Selector::Expression.new(config.integration.all_tests),
+      selector:         Mutant::Selector::Expression.new(config.integration),
       actor_env:        Mutant::Actor::Env.new(Thread)
     )
   end

spec/unit/mutant/env_spec.rb

@@ -61,7 +61,6 @@ RSpec.describe Mutant::Env do
         expect(context).to receive(:root).with(s(:nil)).and_return(wrapped_node).ordered
         expect(Mutant::Loader::Eval).to receive(:call).with(wrapped_node, mutation_subject).and_return(nil).ordered
         expect(integration).to receive(:call).with(tests).and_return(test_result).ordered
-        expect(test_result).to receive(:update).with(tests: tests).and_return(test_result).ordered
       end
 
       include_examples 'mutation kill'

spec/unit/mutant/expression_spec.rb

@@ -44,6 +44,13 @@ RSpec.describe Mutant::Expression do
     it_should_behave_like 'an idempotent method'
   end
 
+  describe '#_dump' do
+    let(:object) { described_class.parse('Foo') }
+    subject { object._dump(double('Level')) }
+
+    it { should eql('Foo') }
+  end
+
   describe '.parse' do
     subject { object.parse(input) }
 
@@ -64,4 +71,10 @@ RSpec.describe Mutant::Expression do
       it { should eql(Mutant::Expression::Namespace::Exact.new('Foo')) }
     end
   end
+
+  describe '._load' do
+    subject { described_class._load('Foo') }
+
+    it { should eql(described_class.parse('Foo')) }
+  end
 end

spec/unit/mutant/result/subject_spec.rb

@@ -2,7 +2,8 @@ RSpec.describe Mutant::Result::Subject do
   let(:object) do
     described_class.new(
       subject:          mutation_subject,
-      mutation_results: mutation_results
+      mutation_results: mutation_results,
+      tests:            []
     )
   end
 

spec/unit/mutant/selector/expression_spec.rb

@@ -1,6 +1,6 @@
 RSpec.describe Mutant::Selector::Expression do
   describe '#call' do
-    let(:object) { described_class.new(all_tests) }
+    let(:object) { described_class.new(integration) }
 
     let(:subject_class) do
       Class.new(Mutant::Subject) do