Fixes capitalized I's when emojiis are present after the text being edited.

[dchersey]

Fixes #21243.
Fixes #20908.

Credit goes to @superandrew213 who provided the patch based on 0.56; this commit merges and resolved the conflict introduced in 0.57.

Test Plan:

When you have an emoji as the last character of your text input and then move the text cursor back (still with emoji as last character) and enter new letters somewhere in the middle of the string, the TextInput begins to capitalize all letter I's without this PR.

Without this PR in place:

1. Create a TextInput on a View
2. Run it on IOS in development or release build in a simulator or on a device
3. Type "Test with emoji 😃"
4. Move the curser back before the emojii
5. Type "edited". The text will appear as "edIted".
6. Apply this PR
7. Run it again
8. Type "Test with emoji 😃"
9. Move the curser back before the emojii
10. Type "edited". The text will now appear as "edited".

Release Notes:

Help reviewers and the release process by writing your own release notes. See below for an example.

[IOS] [BUGFIX] [TextInput] - Fixes bug where letter I's are permanently capitalized when editing text that appears before emojiis

[matthargett]

Can you add an e2e test for this?

[dchersey]

@matthargett I'm game to do so; I've been able to build and run RNTester and I see the TextInputExample ... I guess I just need to add an example showing my emojii bug & testing the fix.

This is my first contribution to RN and I haven't been able to figure out how to actually add the test ... the doc is not super-helpful unfortunately. Can you point me in a direction?

[mikefogg]

Hey guys, any update on getting this fix in there?

[matthargett]

I tried extending the current RNTester e2e tests to exercise things in this way, but had some trouble once the keyboard changes locales. GOing to mark this as approve and follow up with other folks. Thanks!

[kelset]

@facebook-github-bot shipit

[facebook-github-bot]

@kelset is landing this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[facebook-github-bot]

I tried to merge this pull request into the Facebook internal repo but some checks failed. To unblock yourself please check the following: Does this pull request pass all open source tests on GitHub? If not please fix those. Does the code still apply cleanly on top of GitHub master? If not can please rebase. In all other cases this means some internal test failed, for example a part of a fb app won't work with this pull request. I've added the Import Failed label to this pull request so it is easy for someone at fb to find the pull request and check what failed. If you don't see anyone comment in a few days feel free to comment mentioning one of the core contributors to the project so they get a notification.

[cpojer]

Thank you!

[facebook-github-bot]

@cpojer is landing this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[react-native-bot]

@dchersey merged commit f307ac7 into facebook:master.