anchor.diff:      expect(expression.operator, isNotNull);
       expect(expression.operator.type, TokenType.EQ_EQ);
       expect(expression.rightOperand, isNotNull);
  -  }
  -
  -  void test_parseExportDirective_configuration_multiple() {
  -    createParser("export 'lib/lib.dart' if (a) 'b.dart' if (c) 'd.dart';");
  -    ExportDirective directive = parseFullDirective();
  -    expectNotNullIfNoErrors(directive);
  -    listener.assertNoErrors();
  -    expect(directive.keyword, isNotNull);
  -    expect(directive.uri, isNotNull);
  -    expect(directive.configurations, hasLength(2));
  -    _expectDottedName(directive.configurations[0].name, ['a']);
  -    _expectDottedName(directive.configurations[1].name, ['c']);
  -    expect(directive.combinators, hasLength(0));
  -    expect(directive.semicolon, isNotNull);
  -  }
  -
  -  void test_parseExportDirective_configuration_single() {
  -    createParser("export 'lib/lib.dart' if (a.b == 'c.dart') '';");
  -    ExportDirective directive = parseFullDirective();
  -    expectNotNullIfNoErrors(directive);
  -    listener.assertNoErrors();
  -    expect(directive.keyword, isNotNull);
  -    expect(directive.uri, isNotNull);
  -    expect(directive.configurations, hasLength(1));
  -    _expectDottedName(directive.configurations[0].name, ['a', 'b']);
  -    expect(directive.combinators, hasLength(0));
  -    expect(directive.semicolon, isNotNull);
  -  }
  -
  -  void test_parseExportDirective_hide() {
  -    createParser("export 'lib/lib.dart' hide A, B;");
  -    ExportDirective directive = parseFullDirective();
  -    expectNotNullIfNoErrors(directive);
  -    listener.assertNoErrors();
  -    expect(directive.keyword, isNotNull);
  -    expect(directive.uri, isNotNull);
  -    expect(directive.combinators, hasLength(1));
  -    expect(directive.semicolon, isNotNull);
  -  }
  -
  -  void test_parseExportDirective_hide_show() {
  -    createParser("export 'lib/lib.dart' hide A show B;");
  -    ExportDirective directive = parseFullDirective();
  -    expectNotNullIfNoErrors(directive);
  -    listener.assertNoErrors();
  -    expect(directive.keyword, isNotNull);
  -    expect(directive.uri, isNotNull);
  -    expect(directive.combinators, hasLength(2));
  -    expect(directive.semicolon, isNotNull);
  -  }
  -
  -  void test_parseExportDirective_noCombinator() {
  -    createParser("export 'lib/lib.dart';");
  -    ExportDirective directive = parseFullDirective();
  -    expectNotNullIfNoErrors(directive);
  -    listener.assertNoErrors();
  -    expect(directive.keyword, isNotNull);
  -    expect(directive.uri, isNotNull);
  -    expect(directive.combinators, hasLength(0));
  -    expect(directive.semicolon, isNotNull);
  -  }
  -
  -  void test_parseExportDirective_show() {
  -    createParser("export 'lib/lib.dart' show A, B;");
  -    ExportDirective directive = parseFullDirective();
  -    expectNotNullIfNoErrors(directive);
  -    listener.assertNoErrors();
  -    expect(directive.keyword, isNotNull);
  -    expect(directive.uri, isNotNull);
  -    expect(directive.combinators, hasLength(1));
  -    expect(directive.semicolon, isNotNull);
  -  }
  -
  -  void test_parseExportDirective_show_hide() {
  -    createParser("export 'lib/lib.dart' show B hide A;");
  -    ExportDirective directive = parseFullDirective();
  -    expectNotNullIfNoErrors(directive);
  -    listener.assertNoErrors();
  -    expect(directive.keyword, isNotNull);
  -    expect(directive.uri, isNotNull);
  -    expect(directive.combinators, hasLength(2));
  -    expect(directive.semicolon, isNotNull);
     }
   
     void test_parseExpression_assign() {
  
positive.code:     expect(literal.isSynthetic, isTrue);
    }
  
    void test_function_literal_allowed_at_toplevel() {
      parseCompilationUnit("var x = () {};");
    }
  
    void
        test_function_literal_allowed_in_ArgumentList_in_ConstructorFieldInitializer() {
      parseCompilationUnit("class C { C() : a = f(() {}); }");
    }
  
    void
        test_function_literal_allowed_in_IndexExpression_in_ConstructorFieldInitializer() {
      parseCompilationUnit("class C { C() : a = x[() {}]; }");
    }
  
    void
        test_function_literal_allowed_in_ListLiteral_in_ConstructorFieldInitializer() {
      parseCompilationUnit("class C { C() : a = [() {}]; }");
    }
  
    void
        test_function_literal_allowed_in_MapLiteral_in_ConstructorFieldInitializer() {
      parseCompilationUnit("class C { C() : a = {'key': () {}}; }");
    }
  
    void
        test_function_literal_allowed_in_ParenthesizedExpression_in_ConstructorFieldInitializer() {
      parseCompilationUnit("class C { C() : a = (() {}); }");
    }
  
    void
        test_function_literal_allowed_in_StringInterpolation_in_ConstructorFieldInitializer() {
      parseCompilationUnit("class C { C() : a = \"\${(){}}\"; }");
    }
  
    void test_import_as_show() {
      parseCompilationUnit("import 'dart:math' as M show E;");
    }
  
    void test_import_show_hide() {
      parseCompilationUnit(
          "import 'import1_lib.dart' show hide, show hide ugly;");
    }
  
    void test_isFunctionDeclaration_nameButNoReturn_block() {
      expect(_isFunctionDeclaration("f() {}"), isTrue);
    }
  
negative.code:     listener.assertNoErrors();
      expect(configuration.ifKeyword, isNotNull);
      expect(configuration.leftParenthesis, isNotNull);
      expectDottedName(configuration.name, ["a", "b"]);
      expect(configuration.equalToken, isNotNull);
      expect(configuration.value, isNotNull);
      expect(configuration.rightParenthesis, isNotNull);
  