react/scripts/error-codes
Luna Ruan 3278d24218
Add useOpaqueIdentifier Hook (#17322)
* Add useOpaqueIdentifier Hook

We currently use unique IDs in a lot of places. Examples are:
  * `<label for="ID">`
  * `aria-labelledby`

This can cause some issues:
  1. If we server side render and then hydrate, this could cause an
     hydration ID mismatch
  2. If we server side render one part of the page and client side
     render another part of the page, the ID for one part could be
     different than the ID for another part even though they are
     supposed to be the same
  3. If we conditionally render something with an ID ,  this might also
     cause an ID mismatch because the ID will be different on other
     parts of the page

This PR creates a new hook `useUniqueId` that generates a different
unique ID based on whether the hook was called on the server or client.
If the hook is called during hydration, it generates an opaque object
that will rerender the hook so that the IDs match.

Co-authored-by: Andrew Clark <git@andrewclark.io>
2020-04-06 17:17:27 -07:00
..
__tests__ Pass prod error messages directly to constructor (#17063) 2019-10-11 09:10:40 -07:00
codes.json Add useOpaqueIdentifier Hook (#17322) 2020-04-06 17:17:27 -07:00
extract-errors.js Use babel parser rather than Babylon in extract errors (#17988) 2020-02-06 12:46:32 +00:00
invertObject.js Drop the year from Facebook copyright headers and the LICENSE file. (#13593) 2018-09-07 15:11:23 -07:00
README.md Fix link on error-codes/README.md (#16595) 2019-08-28 15:49:45 +01:00
transform-error-messages.js Pass prod error messages directly to constructor (#17063) 2019-10-11 09:10:40 -07:00
Types.js Update Flow to 0.84 (#17805) 2020-01-09 14:50:44 +00:00

The error code system substitutes React's error messages with error IDs to provide a better debugging support in production. Check out the blog post here.

  • codes.json contains the mapping from IDs to error messages. This file is generated by the Gulp plugin and is used by both the Babel plugin and the error decoder page in our documentation. This file is append-only, which means an existing code in the file will never be changed/removed.
  • extract-errors.js is an node script that traverses our codebase and updates codes.json. You can test it by running yarn extract-errors.
  • transform-error-messages is a Babel pass that rewrites error messages to IDs for a production (minified) build.