A new module has been added (ReactFiberErrorLogger). This logs error information (call stack and component stack) to the console to make errors easier to debug. It also prompts users to use error boundaries if they are not already using them.
In the future, perhaps this will be injectable, enabling users to provide their own handler for custom processing/logging. For the time being, this should help with issues like this / #2461.
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.
We currently write all our tests against the DOM implementation.
I need a way to run the Fiber tests against it. But I don't want
to take on any package dependencies on Fiber modules yet.
There's a problem with jest right now where you can't globally
mock modules that already exist. So I have to add a global call
to jest.mock.
Luckily we already have a way to test the useCreateElement paths
using a feature flag. I won't activate this flag in travis until
it passes, but the idea is to run all three variants in travis.
I'm not sure that invoking rAF and rIC synchronously is the best
way to test this since it doesn't capture the backwards
compatibility aspect. I.e. the fact that people might be relying
on the synchronous nature in real apps too. It's a start.
Ideally, jest would have these built-in.
Andrew Clark
