NestJS：如何在 canActivate 中模拟 ExecutionContext

我在模拟 Guard 中间件中的 ExecutionContext 时遇到问题。

这是我的 RoleGuard 扩展 JwtGuard

@Injectable()
export class RoleGuard extends JwtAuthGuard {
 ...
 async canActivate(context: ExecutionContext): Promise<boolean> {
    const request = context.switchToHttp().getRequest();
    const params = request.params;

    ...
 }
}

这就是我在单元测试中尝试的内容。

let context: ExecutionContext = jest.genMockFromModule('@nestjs/common');
  
context.switchToHttp = jest.fn().mockResolvedValue({
  getRequest: () => ({
   originalUrl: '/',
   method: 'GET',
   params: undefined,
   query: undefined,
   body: undefined,
  }),
  getResponse: () => ({
    statusCode: 200,
  }),
});
    
jest.spyOn(context.switchToHttp(), 'getRequest').mockImplementation(() => {
 return Promise.resolve(null);
});

我遇到了这种错误。

Cannot spy the getRequest property because it is not a function; undefined given instead

我希望您建议任何其他方式来模拟上下文。谢谢。

请检查这个库https://www.npmjs.com/package/@golevelup/ts-jest https://www.npmjs.com/package/@golevelup/ts-jest

然后您可以如下模拟 ExecutionContext。

import { createMock } from '@golevelup/ts-jest';
import { ExecutionContext } from '@nestjs/common';
 
describe('Mocked Execution Context', () => {
  it('should have a fully mocked Execution Context', () => {
    const mockExecutionContext = createMock<ExecutionContext>();
    expect(mockExecutionContext.switchToHttp()).toBeDefined();

    ...

  });
});

希望能帮助到你