我们具有这样的函数:
export function* postPermitApplicationRequest() {
try {
const uris = yield select(state => getUris(state));
.... (more yields hereafter)
我们用Jest和Chai测试此功能如下:
...
const action = { type: Action.POST_PERMIT_APPLICATION };
const generator = postPermitApplicationRequest(action);
it('must select uris from state', () => {
const nextCall = generator.next().value;
const uris = select(state => getUris(state));
expect(nextCall).to.deep.equal(uris);
});
但是期望失败:
AssertionError: expected { Object (@@redux-saga/IO, SELECT) } to deeply equal { Object (@@redux-saga/IO, SELECT) }
at Assertion.assertEqual (node_modules/chai/lib/chai/core/assertions.js:485:19)
at Assertion.ctx.(anonymous function) [as equal] (node_modules/chai/lib/chai/utils/addMethod.js:41:25)
at Object.<anonymous> (src/app/pa/PermitApplicationServiceSagas.test.js:20:43)
at process._tickCallback (internal/process/next_tick.js:109:7)
两个对象都看起来像:
{ '@@redux-saga/IO': true,
SELECT: { selector: [Function], args: [] } }
但是,选择器函数不同。gentator.next()的结果包含代码覆盖范围的提示:
function (state) {/* istanbul ignore next */cov_zrpq42gyn.f[12]++;cov_zrpq42gyn.s[19]++;return (/* istanbul ignore next */(0, _Selectors.getUris)(state));}
虽然原始功能没有:
function (state) {return (0, _Selectors.getUris)(state);}
看起来像Genertator.next()添加了这些提示,并且断言失败
我们在这里错了什么?
我们使用Redux-Saga 0.14.8
测试失败,因为在您的传奇和测试中,您每次执行代码时都会创建一个新功能。这两个功能将被比较,但不是同一实例。
您可以在传奇和测试中使用select(getUris)
,因为两者都会参考相同的功能。
您的传奇:
export function* postPermitApplicationRequest() {
try {
const uris = yield select(getUris);
.... (more yields hereafter)
您的测试:
...
const action = { type: Action.POST_PERMIT_APPLICATION };
const generator = postPermitApplicationRequest(action);
it('must select uris from state', () => {
const nextCall = generator.next().value;
const uris = select(getUris);
expect(nextCall).to.deep.equal(uris);
});