Merge pull request #791 from mbj/improve/example-verification

Improve example verification

lib/mutant/meta/example/verification.rb

@@ -11,7 +11,7 @@ module Mutant
         #
         # @return [Boolean]
         def success?
-          missing.empty? && unexpected.empty? && no_diffs.empty?
+          [missing, unexpected, no_diffs, invalid_syntax].all?(&:empty?)
         end
 
         # Error report
@@ -26,6 +26,7 @@ module Mutant
             'original_source' => example.source,
             'missing'         => format_mutations(missing),
             'unexpected'      => format_mutations(unexpected),
+            'invalid_syntax'  => format_mutations(invalid_syntax),
             'no_diff'         => no_diff_report
           )
         end
@@ -34,12 +35,35 @@ module Mutant
 
         # Unexpected mutations
         #
-        # @return [Array<Parser::AST::Node>]
+        # @return [Array<Mutation>]
         def unexpected
-          mutations.map(&:node) - example.expected
+          mutations.reject do |mutation|
+            example.expected.include?(mutation.node)
+          end
         end
         memoize :unexpected
 
+        # Missing mutations
+        #
+        # @return [Array<Mutation>]
+        def missing
+          (example.expected - mutations.map(&:node)).map do |node|
+            Mutation::Evil.new(self, node)
+          end
+        end
+        memoize :missing
+
+        # Mutations that generated invalid syntax
+        #
+        # @return [Enumerable<Mutation>]
+        def invalid_syntax
+          mutations.reject do |mutation|
+            ::Parser::CurrentRuby.parse(mutation.source)
+          rescue ::Parser::SyntaxError # rubocop:disable Lint/HandleExceptions
+          end
+        end
+        memoize :invalid_syntax
+
         # Mutations with no diff to original
         #
         # @return [Enumerable<Mutation>]
@@ -50,14 +74,14 @@ module Mutant
 
         # Mutation report
         #
-        # @param [Array<Parser::AST::Node>] nodes
+        # @param [Array<Mutation>] mutations
         #
         # @return [Array<Hash>]
-        def format_mutations(nodes)
-          nodes.map do |node|
+        def format_mutations(mutations)
+          mutations.map do |mutation|
             {
-              'node'   => node.inspect,
-              'source' => Unparser.unparse(node)
+              'node'   => mutation.node.inspect,
+              'source' => mutation.source
             }
           end
         end
@@ -74,14 +98,6 @@ module Mutant
           end
         end
 
-        # Missing mutations
-        #
-        # @return [Array<Parser::AST::Node>]
-        def missing
-          example.expected - mutations.map(&:node)
-        end
-        memoize :missing
-
       end # Verification
     end # Example
   end # Meta

spec/unit/mutant/meta/example/verification_spec.rb

@@ -75,6 +75,7 @@ RSpec.describe Mutant::Meta::Example::Verification do
           - node: s(:nil)
             source: nil
           unexpected: []
+          invalid_syntax: []
           no_diff: []
         REPORT
       end
@@ -95,6 +96,7 @@ RSpec.describe Mutant::Meta::Example::Verification do
             source: 'false'
           - node: s(:nil)
             source: nil
+          invalid_syntax: []
           no_diff: []
         REPORT
       end
@@ -112,11 +114,41 @@ RSpec.describe Mutant::Meta::Example::Verification do
           original_source: 'true'
           missing: []
           unexpected: []
+          invalid_syntax: []
           no_diff:
           - node: s(:true)
             source: 'true'
         REPORT
       end
     end
+
+    context 'when the generated node is invalid syntax after unparsed' do
+      let(:invalid_node) do
+        s(:op_asgn, s(:send, s(:self), :at, s(:int, 1)), :+, s(:int, 1))
+      end
+
+      let(:expected_nodes)  { [invalid_node] }
+      let(:generated_nodes) { [invalid_node] }
+
+      specify do
+        should eql(<<~'REPORT')
+          ---
+          file: foo.rb
+          original_ast: s(:true)
+          original_source: 'true'
+          missing: []
+          unexpected: []
+          invalid_syntax:
+          - node: |-
+              s(:op_asgn,
+                s(:send,
+                  s(:self), :at,
+                  s(:int, 1)), :+,
+                s(:int, 1))
+            source: self.at(1) += 1
+          no_diff: []
+        REPORT
+      end
+    end
   end
 end