* Add iterable cases to MultiChildReconcile test
Stack currently supports rendering iterables, but Fiber does not.
Previously we didn't have any public API tests for iterables. We have tests for traverseAllChildren() which is shared between React.Children and Stack. However Fiber doesn't currently use it, and likely won't. So this commit is a first step towards actually testing iterable support via public API. The next step will be to port traverseAllChildren() tests to test React.Children API instead.
* Implement iterable reconciliation in Fiber
This uses the same exact algorithm as array reconciliation but uses iterator to step through.
This gets reconcile tests to pass again but introduces a regression in ReactMultiChildText case which uses Maps as children. It passed before because Maps were ignored, but now it's failing because this actually runs the Map code path in Fiber. We can throw early in this case when we want to follow up on this.
* Rewrite traverseAllChildren() tests against React.Children API
This function was used in React.Children and Stack.
The corresponding reconciliation functionality is being tested by ReactMultiChild tests.
So we can move these tests to ReactChildren and test its public API.
We need this to safely extract the current event listeners from the props.
Unfortunately, we are still not safe to use the return pointer since it
may not point to the current tree when the Fiber is reused. So this is not
fully done yet.
* Use the public ReactDOMServer in tests
We need this because it runs the injection.
* Let Fiber skip react data attributes and comments in SSR tests
This markup is testing implementation details rather than behavior.
I'll plan to change all of our console.error and component-tree expects to expectDev. It's a little annoying that we need to make sure tests don't throw (see my change to normalizeCodeLocInfo) but any alternative would seem to require two separate test runs or a much more cumbersome syntax.
Ben Alpert