Upgrade to RN v0.59

[gnprice]

React Native 0.59 is out!
https://facebook.github.io/react-native/blog/2019/03/12/releasing-react-native-059

We should upgrade.

This is a big release with a lot of changes. Major things I'm eager to get include (details in above-linked post):

• updated JS implementation on Android, which has been ancient (should help perf; and blocks Meet 64-bit requirement, by 2019-08 deadline #3323)
• React Hooks
• CLI improvements

[gnprice]

Update from a chat with @borisyankov today: there are two areas of work remaining to complete this:

• The Android build changes in android/. Boris will take this on, for the sake of alternation/cross-training because I've done most of the Android build work in recent months.
• Flow type errors. These break down as:
  • Three open PRs:
    • Add Flow types required for RN 0.59 migration #3442 (merged Apr 26 next step: @borisyankov reply to my previous review)
    • Fix type of connect to fully work, and to work with newer Flow. #3450
    • More type fixes for RN v0.59 / Flow v0.92 #3453
  • Some places that need a SelectorProps annotation; see comment on #3450. (Done in e7ee1c9.)
  • Possibly a handful of stragglers? We'll see when those are all done.

[gnprice]

OK, reviewing current status, referring to the latest version of the draft PR #3422:

• Still the Android build changes in android/. These are on my plate now.
• We're down to a handful of type errors:
  • The screen: HomeTab, screen: PmConversationsCard, etc., in MainTabs.js and StreamTabs.js, give errors. I'm kind of tired of trying to untangle the maze of similarly-named types in the react-navigation libdef -- I think I'm going to just mark these with FlowFixMe and write these off as a react-navigation issue that we can live with.
  • Unused suppression comment 🎉 in AppWithNavigation.js. We can do the same dance we've done before where we disable errors on unused such comments; do the upgrade; remove the now-unused comment; then re-enable the errors. (The enabling and disabling is a one-line change in .flowconfig.)
• I get an error on running jest: Preset react-native not found. Not sure offhand if we had that error on previous versions of the PR. Probably something easy to fix, but investigation needed.
• I'll want to go through the sequence of things in the PR and answer the questions I asked in my original review feedback. Most likely I'll end up pulling some pieces out into separate preceding commits, like upgrading various ancillary dependencies, and upgrading libdefs.

[gnprice]

A few more notes:

• The recommended tool these days for driving these upgrades is rn-diff-purge.
  • Basically you get a diff between a fresh hello-world app generated from upstream's templates at the two different versions. This is a pretty great technique!
  • For these two versions, it looks like

$ git diff --stat=92 version/{0.57.8,0.59.8}
 RnDiffApp/.babelrc                                         |  3 ---
 RnDiffApp/.flowconfig                                      |  3 +--
 RnDiffApp/__tests__/App-test.js                            | 14 +++++++++++++
 RnDiffApp/android/app/BUCK                                 | 18 ++++------------
 RnDiffApp/android/app/build.gradle                         | 13 ++++++------
 RnDiffApp/android/app/build_defs.bzl                       | 19 +++++++++++++++++
 RnDiffApp/android/app/src/debug/AndroidManifest.xml        |  8 +++++++
 RnDiffApp/android/app/src/main/AndroidManifest.xml         |  4 ++--
 RnDiffApp/android/build.gradle                             | 16 +++++---------
 RnDiffApp/android/gradle/wrapper/gradle-wrapper.properties |  2 +-
 RnDiffApp/babel.config.js                                  |  3 +++
 RnDiffApp/index.js                                         |  4 +++-
 RnDiffApp/ios/RnDiffApp.xcodeproj/project.pbxproj          |  8 +++++++
 RnDiffApp/ios/RnDiffApp/AppDelegate.h                      |  5 +++--
 RnDiffApp/ios/RnDiffApp/AppDelegate.m                      | 29 ++++++++++++++------------
 RnDiffApp/ios/RnDiffApp/main.m                             |  2 +-
 RnDiffApp/ios/RnDiffAppTests/RnDiffAppTests.m              |  2 +-
 RnDiffApp/metro.config.js                                  | 17 +++++++++++++++
 RnDiffApp/package.json                                     | 16 +++++++-------
 19 files changed, 122 insertions(+), 64 deletions(-)

(The number after --stat= is just the width to tell git diff to print at; that's what it takes to avoid an ellipsis on the long gradle-wrapper pathname.)

• I'll want to go through that diff -- it'll be quite helpful in answering the questions I mentioned above, and probably separating out some pieces.

• There's a v0.59.9 now, so we'll want that instead of v0.59.8.

• There's also a v0.60.0-rc.0 and v0.60.0-rc.1. So, almost time for the next upgrade -- we'll aim to do that one faster 😉

[gnprice]

Bumping to P0 to follow #3323, which this blocks.

[gnprice]

A couple of miscellaneous links -- things that looked likely useful when I was digging into this for the comments just above -- so I can close those tabs:
react-native-community/discussions-and-proposals#68 (comment)
https://brucelefebvre.com/blog/2019/04/03/react-native-upgrade-by-example/

[gnprice]

Done! Details in dfbdd97; in more detail in #3561; and more detail in the many commits mentioned in dfbdd97, including the majority of the 58 commits in git log 1c86488ce^..ed490db13.

A few post-upgrade followups remain to do. I'll post those separately, with references to here.