使用HttpTestingController拦截HTTP请求并检查查询参数是否正确。示例代码：

import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';
import { TestBed } from '@angular/core/testing';
import { HttpClient } from '@angular/common/http';

describe('my test', () => {
  let httpClient: HttpClient;
  let httpTestingController: HttpTestingController;

  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [HttpClientTestingModule],
      providers: [],
    });
    httpClient = TestBed.inject(HttpClient);
    httpTestingController = TestBed.inject(HttpTestingController);
  });

  afterEach(() => {
    httpTestingController.verify();
  });

  it('should send correct query params', () => {
    const searchText = 'test';
    const expectedParams = { q: 'test', limit: 10 };

    httpClient.get('http://example.com/search?q=test&limit=10').subscribe();

    const req = httpTestingController.expectOne((request) => {
      return (
        request.url === 'http://example.com/search' &&
        request.params.get('q') === searchText &&
        request.params.get('limit') === expectedParams.limit.toString()
      );
    });

    req.flush({});
  });
});

在此示例中，我们使用HttpClientTestingModule模块和HttpTestingController类来创建一个模拟的HttpClient实例，并拦截发出的HTTP请求，以检查查询参数是否正确。我们使用expectOne函数来请求HTTP请求，并使用参数谓词来检查请求的URL和查询参数。如果参数匹配，我们将使用req.flush函数来模拟HTTP响应。

请注意，HttpTestingController会自动管理用于拦截HTTP请求的模拟XHR。在每个测试之后，请使用httpTestingController.verify函数来验证没有未处理的请求。