facebook
fix(types): incorrect <void> use in typescript
Summary
The use of void as a type parameter is semantically different in TS than Flow. Specifically, providing void in Flow will result in the use of the default type parameter value, while TS will treat it as an explicit use of void for the generic.
Original Issue: https://github.com/facebook/metro/issues/1491
Changelog:
[Fix] Bundler types (transformFile)
[Fix] IncrementalBundler types (OutputGraph, getDeltaBundler, getDependencies, buildGraph, initializeGraph and updateGraph)
[Fix] Worker types (transform)
[Fix] Metro.buildGraph return type
Test plan
Oof. This may be a larger discussion as keeping the TS and Flow types in-sync and correct may be a moving target as the project evolves. For now, the verification is "when consuming this code in a TS codebase, types are the same as if I was consuming the flow annotated code"
Thanks @nickhudkins!
Several Metro packages do now have automatic TS types, but there are a few patterns unsupported by the translator and/or TS itself so we've been refactoring and touching up package-by-package to get translations working (any PRs to get us closer would be appreciated as well!). metro-config for example is automatic and validated in CI, but metro isn't.
https://github.com/facebook/metro/blob/main/scripts/generateTypeScriptDefinitions.js#L29
I actually saw this and began down the path of doing type generation for metro, let me see if I can take an incremental approach here!
Alrighty... metro types are gonna take some more significant work, especially just trying to reconcile flow types with typescript, especially those that have spreads at the end