测试Redux-Saga的“收益率电话”

Question

I'm trying to write a unit test to the following saga :

 function * verifyCode(api){ let action = yield take(LoginTypes.VERIFY_CODE) const phoneNumber = yield select(phoneNumberSelector) try{ const response = yield call(api.verifyCode, phoneNumber, action.code) if (response.ok){ let token = response.data.token yield put(LoginActions.verifyCodeSuccess(response.data.token)) } else { yield put(LoginActions.verifyCodeFailure(response.error)) } } catch(error){ yield put(LoginActions.verifyCodeFailure(error)) } } 

All the tests pass up until the 'yield call' part, using the following (using test from 'tape'):

 test('verify code flow', (assert) => { let number = '0000000' let code = '00000' const gen = verifyCode(api) assert.deepEqual( gen.next({code: code}).value, take(LoginTypes.VERIFY_CODE), 'wait for verify code action from user', ) assert.deepEqual( gen.next().value, select(phoneNumberSelector), 'get phoneNumber from login state' ) assert.deepEqual( gen.next().value, call(api.verifyCode, number, code), 'call verify code' ) assert.end() }) 

The error I get for the failure of this test is

   operator: deepEqual
expected: |-
  { '@@redux-saga/IO': true, CALL: { context: null, fn: [Function: verifyCode], args: [ '0000000', '00000' ] } }
actual: |-
  { '@@redux-saga/IO': true, PUT: { channel: null, action: { type: 'VERIFY_CODE_FAILURE', error: [TypeError: Cannot read property 'code' of undefined] } } }

1. What is the correct way to write to an api call using the 'call' effect?
2. How can I test the different possible flows depending on the ''response I get?

Answer 1

1. This is the correct way to use the call effect on an API
2. To test different flows (Success | Failure) you can use the following pattern (in Jest):

 expect(generator.next().value.PUT.action).toMatchObject({type: types.VERIFY_CODE_SUCCESS, payload: {}, meta: { section }}); expect(generator.throw('error').value.PUT.action).toMatchObject({ type: VERIFY_CODE_FAILURE, payload: 'error'}); 

BTW: It seems that your test fails due to an error thrown when you called your API endpoint. Make sure you get the desired response from your endpoint.

Good Luck!