anchor.diff:      expect(matches, hasLength(1));
       return matches.first;
     }
  +
  +  void _assertNoErrorsInProjectFiles() {
  +    var errors = <AnalysisError>[];
  +    driver.filesErrors.forEach((file, fileErrors) {
  +      // Completion test files are likely to be incomplete and so may have
  +      // errors
  +      if (file != testFilePath) {
  +        errors.addAll(fileErrors);
  +      }
  +    });
  +    expect(errors, isEmpty);
  +  }
   }
   
   @reflectiveTest
  
positive.code:     await driver.waitForSetWithUri(uriStr);
    }
  
    Future<void> addTestFile(String content, {int offset}) async {
      driver.addTestFile(content, offset: offset);
      await getSuggestions();
    }
  
    void expectNoSuggestion({
  
negative.code:   ^
  }
  ''');
  
      expectSuggestion(
          completion: 'A',
  