用node / js在第三方js库中模拟HTTP请求的最简单或惯用的方法是什么

Question

When I've coded in Ruby or Python, I've been able to use libraries like VCR that intercept HTTP requests, and record them, so when for example I'm hitting an 3rd party API in tests, I can save that response as a fixture instead of manually building a huge mock objects to check behaviour against.

It's not perfect, but it has saved a load of time when I've been exploring which API requests to make against a third party API, (often wrapping a 3rd party library), then writing tests to check this behaviour.

What's the closest thing in JS these days to this?

I'm looking for an open source tool I can require in my test files, so when I run tests where I might call methods on third party APIs, I don't make expensive, slow HTTP requests. I imagine the code might look a bit like:

it('does something I expect it to', () {

  // set up some state I care about
  let someVar = someSetupCode()

  let library = thirdPartyLib({creds: 'somecreds'})
  library.someMethod()

  // check state has changed 
  expect(someVar.value).toBe('what I Expect after calling someMethod')

})

Where here, when I call library.someMethod() , instead of hitting actual servers, I'm checking against the values the server would be returning, that I've saved previously.

Monkey patching an existing library or function

I see things fetch-vcr , or axios-vcr , but these seem to rely on explicitly reaching into a library to replace say, a call to fetch with the http-intercepting version instead, be reading a 'cassette' file containing the canned response.

I'm looking for a way to avoid patching 3rd party code if I can help it, a this is how I understand VCR works for other languages.

Presumably, if there's an HTTP client built somewhere into node then that would be the place you'd patch a function - I haven't come across a specific library that does this.

Running an entire HTTP server

Alternatively I can see libraries like vcr.js , or yakbak , which essentially set up an HTTP server which serves JSON blobs you define, at various urls, like serving a saved users.json file at http://localhost:8100/users/

This is okay, but again, if I don't need to spin up a whole HTTP server, and make actual HTTP requests, that would be wonderful.

Answer 1

Oh, hang on, it looks like sepia from linkedin works well for nodejs at least.

I haven't looked into it too much, but I'd welcome comments if you have been using it.

Answer 2

Probably SoapUI works for you. Although its name, it also works with REST API.