[CI] Fix test_javascript Snapshot Test failure

[hramos]

• I have reviewed the documentation
• I have searched existing issues
• I am using the latest React Native version

The test_javascript job started failing on master recently: https://circleci.com/gh/facebook/react-native/42926

This is due to failing snapshot tests, mostly in VirtualizedList (expand details below to see an example).

Details

● VirtualizedList › handles nested lists

expect(value).toMatchSnapshot()

Received value does not match stored snapshot "VirtualizedList handles nested lists 1".

- Snapshot
+ Received

@@ -12,11 +12,10 @@
    disableVirtualization={false}
    getItem={[Function]}
    getItemCount={[Function]}
    horizontal={false}
    initialNumToRender={10}
-   invertStickyHeaders={undefined}
    keyExtractor={[Function]}
    maxToRenderPerBatch={10}
    onContentSizeChange={[Function]}
    onEndReachedThreshold={2}
    onLayout={[Function]}
@@ -49,11 +48,10 @@
          disableVirtualization={false}
          getItem={[Function]}
          getItemCount={[Function]}
          horizontal={false}
          initialNumToRender={10}
-         invertStickyHeaders={undefined}
          keyExtractor={[Function]}
          maxToRenderPerBatch={10}
          onContentSizeChange={[Function]}
          onEndReachedThreshold={2}
          onLayout={[Function]}
@@ -103,11 +101,10 @@
          disableVirtualization={false}
          getItem={[Function]}
          getItemCount={[Function]}
          horizontal={true}
          initialNumToRender={10}
-         invertStickyHeaders={undefined}
          keyExtractor={[Function]}
          maxToRenderPerBatch={10}
          onContentSizeChange={[Function]}
          onEndReachedThreshold={2}
          onLayout={[Function]}

  158 |       />,
  159 |     );
> 160 |     expect(component).toMatchSnapshot();
      |                       ^
  161 |   });
  162 | 
  163 |   it('returns the viewableItems correctly in the onViewableItemsChanged callback after changing the data', () => {
  
  at Object.<anonymous> (Libraries/Lists/__tests__/VirtualizedList-test.js:160:23)

This does not repro on a clean local checkout on my laptop, but after some investigation, I narrowed this down to Jest v23.0.0-charlie.2 being used in CI. While our own package.json specifies jest v23.0.0-charlie.1, the metro package v0.37 depends on jest v23.0.0-charlie.2 and thus this version wins out.

The test started failing once metro was bumped to v0.37 in 803afd8.

You can reproduce the failure locally by following the repro steps below.

Environment

CircleCI

Steps to Reproduce

1. Checkout master
2. yarn add --dev jest@23.0.0-charlie.2
3. yarn test

Expected Behavior

Tests should pass.

Actual Behavior

Snapshot tests fail due to non-matching snapshots.

[SimenB]

Your failing test is due to jestjs/jest#6162

[hramos]

@SimenB thanks, seems safe to update these snapshots then. Landing in #19414

Still have one more failure to address:

$ JEST_JUNIT_OUTPUT="reports/junit/js-test-results.xml" jest --maxWorkers=2 --ci --testResultsProcessor="jest-junit"
 FAIL  Libraries/Animated/src/__tests__/AnimatedNative-test.js
  ● Native Animated › Animated Value › proxies `setValue` correctly

    TypeError: jest.genMockFunction is not a function

      82 |       c.refs = {
      83 |         node: {
    > 84 |           setNativeProps: jest.genMockFunction(),
         |                                ^
      85 |         },
      86 |       };
      87 | 

      at Object.<anonymous> (Libraries/Animated/src/__tests__/AnimatedNative-test.js:84:32)

[hramos]

Found your PR, jestjs/jest#6173 - I'll change these to jest.fn.

[hramos]

Now looking at:

Summary of all failing tests
 FAIL  Libraries/Animated/src/__tests__/Animated-test.js
  ● Animated tests › Animated › send toValue when an underdamped spring stops

    Ran 100000 timers, and there are still more! Assuming we've hit an infinite recursion and bailing out...

      140 |       anim.addListener(listener);
      141 |       Animated.spring(anim, {toValue: 15}).start();
    > 142 |       jest.runAllTimers();
          |            ^
      143 |       const lastValue =
      144 |         listener.mock.calls[listener.mock.calls.length - 2][0].value;
      145 |       expect(lastValue).not.toBe(15);

      at FakeTimers.runAllTimers (node_modules/jest-util/build/fake_timers.js:194:13)
      at Object.<anonymous> (Libraries/Animated/src/__tests__/Animated-test.js:142:12)

[SimenB]

That last one I don't know, we haven't changed timers

[hramos]

Agree, seems unrelated. I'm just using this issue to track my progress getting back to green.

The snapshot update has not landed yet as it looks like we're still using 23.0.0-charlie.1 in the internal monorepo, and therefore the new snapshots cause the internal jest snapshot tests to fail.

I've started the process of updating the repo to charlie.2, but that seems like something that @brunotavares might already be planning to do. I'll see if we can just make sure the use of jest in OSS Circle CI matches the internal Sandcastle test behavior.

[SimenB]

charlie.4 is the latest, fwiw. How you do things internally, I have no clue (although I might learn tomorrow! :D)

[hramos]

Bumping the version to charlie.4 is quite straightforward, but I'd need to codemod the rest of the codebase to handle the breaking change in jestjs/jest#6173 as well. Seeing @brunotavares has already done some of this work in another one of our internal repos, I'll let him or his team tackle this.

RN OSS is using jest@23.0.0-charlie.1 but from I recall, some charlie.2 and charlie.4 modules are getting pulled by Yarn. We use an offline repository internally where charlie.1 is the latest cached version, so we don't have this issue.

[hramos]

Jest 23 is now publicly available. I'll wait for our codebase to move to 23, at which point these should be resolved.

[hramos]

SHA-1 issue may be fixed by jestjs/jest#6264

Jest 23 has not yet been configured in the internal monorepo, issue should remain open.