[Proposal] Use the testing framework assertion library for better integration

The current behavior is unmet expectation is to throw an error with a formatted string of unmet expectations.

For small examples it is not an issue, however, when you have nested objects to assert (e.g. 2 level deep objects) or many effects to except the error message becomes very unreadable. It is hard to find what exactly didn’t match.

If we use the testing framework, for example jest, assertion library (expect) errors will be printed using the library’s reporter.

In my case, they will be formatted by WebStorm reporter which have a nice diff view which I missing when using redux-saga-test-plan.

What do you think about this proposal?

[mike1808]

@borrascador it’s the built-in expect in Jest. Try to use it in https://github.com/jfairbank/redux-saga-test-plan/blob/master/src/expectSaga/expectations.js file instead of throw

[mike1808]

For those who are interested. Unfortunately, I didn’t have time to make the code more organized, however, Jest integration works perfectly. I tested my previous project which had a lot of saga tests using this library.

The code is available in my forked repo on this branch https://github.com/mike1808/redux-saga-test-plan/tree/beta-jest

You can try on your projects by installing jest-redux-saga-test-plan@4.0.0-beta.5

Few caveats:

1. This branch is created from upgrade-to-babel7 as its new versions of babel was required to use the new Jest version.
2. The compatibility for old Node.js might be broken because I upgraded Babel and removed some polyfills in the code (like Map), so my fork might not work on Node.js < 8
3. The main code changes are in src/shared/serializeEffect.js file. There you can find that some effects like CANCELLED, FLUSH, CANCEL, JOIN are not implemented.
4. The changes are only for expectSaga. I didn’t touch the unit testing API.

If you have any question about code, feel free to write here, or, if you want to continue my work, we can set up a zoom/skype call and I’ll share all context I have.

cc @dbartholomae @vov462 @Taguhi