update react & react-dom & react-test-renderer to 16.9.0

[senadir]

Updated some packages to the latest React version

changes in React includes:

• renaming deprecated lifecycle methods
  componentWillMount → UNSAFE_componentWillMount
componentWillReceiveProps → UNSAFE_componentWillReceiveProps
componentWillUpdate → UNSAFE_componentWillUpdate
• Async act() for Testing
• Performance Measurements with <React.Profiler>
  and some other stuff you can react in the changelog above

[senadir]

had to delete the node_modules folder because it was causing some cache problems with a core package from another PR, that's why the pacakge-lock is updated to this extend

[gziolo]

had to delete the node_modules folder because it was causing some cache problems with a core package from another PR, that's why the pacakge-lock is updated to this extend

I don't think this is the expected number of changes for the lock file. Can you try doing it again with the original lock file? It should be no more than dozens of lines updated. Did you follow: https://github.com/WordPress/gutenberg/tree/master/packages#production-dependencies?

[senadir]

@gziolo I will try again, the depencedy in question was stylelint-plugin, a package I introduced in another PR, it shouldn't even exist in master or the branch I created, yet npm kept saying he didn't find it, removing node_modules fixed the issue but caused this new lock file

[senadir]

@gziolo seems it worked, I should have kept the lock file & deleted the modules folder, not both

[gziolo]

I nearly forgot about react-native and that we need to wait until the new version is released which works with react 16.9.x.

@koke and @hypest, do you follow progress on the next version of RN?

[koke]

It looks like React Native only upgrades the React dependency on major versions, there's a tracking issue for the next minor one (0.60.5), but I don't know of a timeline for 0.61 yet.

[gziolo]

Great work @senadir. I tested and it all looks good. I rebased to master to ensure it still passes with the latest changes in the master branch.

Can we include a note in the changelog on @wordpress/element before we proceed?

Similar to:
https://github.com/WordPress/gutenberg/blob/master/packages/scripts/CHANGELOG.md#new-features-1

It's rather internal change as we don't introduce new features.

[gziolo]

It looks like React Native 0.61.0 is still not there. However, we'd like to move forward with the changes so we could properly test Gutenberg with React 16.9.0 in the upcoming release cycle of WordPress 5.3. Related RN issue: react-native-community/releases#140.

[gziolo]

I added CHANGELOG entry. Let's move forward with this PR.