React 15.6 Umbrella

[flarnie]

Update: We just shipped 15.6.0 of react & react-dom! :)

Still ongoing;

• Fixes for React.addons and the 15.6.0 release of those modules.
• Follow-up work

---

React.addons fixes:

• Create a build step for UMD builds of addons
  • Update deprecation in prop-types library and check other add-ons for deprecation warnings. Release new versions. (Downgrade deprecation error to warning prop-types#63)
• Why doesn’t TransitionGroup have a deprecation warning? Let’s add if we forgot it. Make sure the wording says “moved” since moving is all that happened.
  • note: we should point to a specific version of the separate module, to make this future-proof against API changes to the transition group modules. Fixed in Use react-transition-group from npm #9937
• Update add-on versions in 15.6 and master branches.
• Fix create-react-class UMD module does not work in AMD environment #9689 and Set 'React' as dependency in AMD builds of addons #9765 (fixed by Add build process to all addons #9946 ?)
• Merge [#9627] Fix create-react-class isMounted ordering issue #9638
• Remove PropTypes dependency from ReactLink #9766
• Release new versions of add-ons
• Cherry-pick all these changes into 15.6

Other related items:

• Document the process for deprecating an API in React Moved to Document the process for deprecating an API in React #10057
• Can we remove junk code from PropTypes prod build? It doesn't use bundle-collapser so it ships all those method names (e.g. “fbjs/lib/invariant”). This is fixable if you add “-p bundle-collapser/plugin” to browserify call. Additionally, there seems to be some junk invariant() code which is easy to fix if we just turn this into an inlined error. https://unpkg.com/prop-types@15.5.6/prop-types.min.js
• Make sure deprecations are on master too

Follow-up issues:

• Find a solution for Backport input fix #8575 (we did merge this after all)
  • Which unblocks adding the tests from e29871e which depend on 'inputValueTracking'
• Further improvements to React warnings in general, specifically to adress Supporting all of v15 without warnings #9466

---

Steps we went through for React 15.6.0;

Preparing the RC:

Done! RC was released.

• Write a proper changelog for 15.5.x releases and 15.6 (Tag 15.5.{1,2,3,4}, update docs #9443)
• Cherry-pick React.createMixin deprecation (Cherry-pick Deprecate React.createMixin #8853)
• Maybe cherry-pick Adds CSS Grid properties to list of unitless numbers #9185? Needs confirmation this is the right way.
• Cherry-pick Use setProperty when setting style properties #9302 if it's merged by then.
• Cherry-pick this fix: Only attempt to clear measures if we created the measure #9451
• Cherry-pick Remove loose check on non-number controlled inputs. Fix trailing dot issue. #9584
• Deduplicate "unknown DOM property" warning so that people don't stay on React 15.1 (see discussion in Supporting all of v15 without warnings #9466) — We have not reached a consensus here and will instead revisit the whole warning system in the future
• Make sure we are using PropTypes.checkPropTypes rather than inlining it (like we did in 15.5)
• Deprecate React.DOM Factories (Merge and cherry-pick Create react-addons-dom-factories package #8356)
  • Include a codemod from React.DOM.stuff to React.createElement('stuff'
• Merge/cherry-pick Backport input fix #8575 :)
• Downgrade console.error to console.warn for deprecation notices
  • Create deprecation 'warning' helper. (Downgrade deprecation warnings from errors to warnings #9650) and (Improve low priority warning #9754)
  • Update all deprecation warnings on master branch. (Downgrade deprecation warnings from errors to warnings #9650)
  • Sync master branch(@flarnie: moved to 'prepping final release' section)
  • Update deprecation in prop-types library and check other add-ons for deprecation warnings. Release new versions. (@flarnie - moved to addons section)
  • Update deprecation warnings on 15.6 branch (Cherrypick commit to downgrade deprecations to warnings #9753)
  • Update add-on versions in 15.6 and master branches. (@flarnie - moved to addons section)
• Add specific version numbers to deprecation messages (“In React 16.0, ...”) (Improve deprecation warnings by more info and links #9768 and Cherrypick warning and removal of react create class #9771)
• Add a link to warning messages. Make it clear that those are not broken code but something that will be removed in React 16. Link to a dedicated page (a gist? a blog post? gists are nice because they have comments) but make sure that page touches on common confusion points:
  • What should lib maintainers do? Dependency or peer? (Improve deprecation warnings by more info and links #9768, Improve warning for React.createClass #9781, and Cherrypick warning and removal of react create class #9771)
  • What does this mean for context API? (Improve deprecation warnings by more info and links #9768, Improve warning for React.createClass #9781, and Cherrypick warning and removal of react create class #9771)
  • Is the warning firing on my code? Or on a dependency? How do I know? (Improve deprecation warnings by more info and links #9768, Improve warning for React.createClass #9781, and Cherrypick warning and removal of react create class #9771)
  • What exactly will happen in React 16? (Improve deprecation warnings by more info and links #9768, Improve warning for React.createClass #9781, and Cherrypick warning and removal of react create class #9771)
  • How to automatically migrate my code? (Improve deprecation warnings by more info and links #9768, Improve warning for React.createClass #9781 and Cherrypick warning and removal of react create class #9771)
  • Are we encouraging people to stop using createClass? What about PropTypes? Are we deprecating them as in “they're bad” (nope) or are we just moving them (yes)? Make it clearer. (Improve deprecation warnings by more info and links #9768, Improve warning for React.createClass #9781, and Cherrypick warning and removal of react create class #9771)
  • Use fb.me for links (just like we always did in deprecations). This lets us update links in the future. (Improve deprecation warnings by more info and links #9768, Improve warning for React.createClass #9781, and Cherrypick warning and removal of react create class #9771)
• Cherry-pick 646e786 to 15.6-dev (Cherrypick warning and removal of react create class #9771)
• Verify that any changes landed in 15-stable were also cherry-picked to 15.6-dev. (Pull all docs updates from 15-stable into 15.6-dev #9889)
• Cherry-pick the fix for Add 'DEV' flag #9569 (@gaearon: I don't think we need to)
• Make sure deprecations are on master too (@flarnie: moved to 'prepping final release' section.)
• Change react-dom-factories package to be named that consistently, and avoid react-addons-dom-factories. (rename react-addons-dom-factories to react-dom-factories #9780)
• Cherry pick Inputs should not mutate value on type conversion (when they stringify to the same thing) #9806 (double check with @nhunzaker)
• Release react-dom-factories on npm.

Testing the RC:

Done! [React 15.6.0 is out.](https://github.com/facebook/react/releases/tag/v15.6.0)

- [X] Inspect the UMD builds - [x] Share RC and proposed release date with library authors several weeks in advance - [x] Publish release notes early

Preparing the final release:

Done! [React 15.6.0 is out.](https://github.com/facebook/react/releases/tag/v15.6.0)

- [x] Update https://github.com/facebook/react/blob/master/scripts/print-warnings/print-warnings.js (https://github.com//pull/9756) - [x] Share RC with library authors and get folks to try it. - [x] Post a target date for the release. - [x] Triage any issues reported with RC. - [x] https://github.com//issues/9830 - [x] Sync master branch (to test the deprecation downgrade internally at FB)

Doing the release:

• Release on a Mon-Thur. day

[aweary]

Deprecate React.DOM Factories

For reference, there is existing work on this at #8356

Can we remove junk code from PropTypes prod build? It doesn't use bundle-collapser so it ships all those method names (e.g. “fbjs/lib/invariant”). This is fixable if you add “-p bundle-collapser/plugin” to browserify call. Additionally, there seems to be some junk invariant() code which is easy to fix if we just turn this into an inlined error. https://unpkg.com/prop-types@15.5.6/prop-types.min.js

I created an issue for this in the new prop-types repo: facebook/prop-types#16

[timdorr]

Are we encouraging people to stop using createClass? What about PropTypes? Are we deprecating them as in “they're bad” (nope) or are we just moving them (yes)? Make it clearer.

You'll want to be crystal clear about this. In other projects where they've removed stuff like this, it usually means a death sentence for those features (Responders in Rails come to mind). The important part is noting that those features aren't going away, just how you access them is changing. Maybe drop the "depreciation" wording and replace it with "moving"? And that's not because you're not deprecating those imports, but it's about the kind of message you want to send.

[markspolakovs]

👍 on not calling it "deprecation". The common intuition for "deprecated" is "stuff that we're no longer maintaining and only keeping around to avoid API incompatibilities, and you shouldn't use it anymore" (see https://en.wikipedia.org/wiki/Deprecation#Software_deprecation). "Moving" sounds a bit better.

[jeremenichelli]

Awesome suggestions by @flarnie, happy to see that more of the bullet points touch communication topics which are way more difficult to embrace than technical stuff sometimes when managing a library that a lot of people uses.

Though I like warnings, I don't know if I prefer the red and error look of a deprecation to catch better the developer's attention.

[aweary]

Awesome suggestions by @flarnie, happy to see that more of the bullet points touch communication topics which are way more difficult to embrace than technical stuff sometimes when managing a library that a lot of people uses.

I completely agree. I think it's especially difficult since most of the React team's core decisions are made via internal discussions at FB, and there hasn't been a sustained effort to communicate these to the OSS community.

I would love to see some work towards making this less opaque (maybe start publishing meeting notes again?), both for consumers, library maintainers, and contributors to the project.

[timdorr]

Though I like warnings, I don't know if I prefer the red and error look of a deprecation to catch better the developer's attention.

This is a complete hack and totally should not be what actually is done here, but you can sorta do that with console message styles:

Silly, but it could be an idea to pursue to make them visually distinct.

[gaearon]

Unfortunately won't work in other browsers or Node afaik.