Add Scheduler API types

[dislido]

⚙ Compilation target

ESNext

⚙ Library

["ESNext", "DOM", "DOM.Iterable"]

Missing / Incorrect Definition

globalThis.scheduler

Sample Code

scheduler.postTask(() => 123, { delay: 0 });

Documentation Link

https://developer.mozilla.org/en-US/docs/Web/API/Scheduler

[Milad93R]

I'll work on this!

For context: DOM type definitions for TypeScript are generated from the TypeScript-DOM-lib-generator repository. There's already an existing PR that adds the Scheduler API types: microsoft/TypeScript-DOM-lib-generator#1249

That PR was blocked in 2022 because only Chromium supported the API at the time. However, Firefox now supports the Scheduler API (version 142+), which means two major browser engines now support it - satisfying the lib-generator's requirement for inclusion.

I've commented on that PR to help move it forward. Once the types are added to the lib-generator, they'll be included in future TypeScript releases.

[Milad93R]

Update: After investigating further, I found that the Scheduler API types have already been added to the TypeScript-DOM-lib-generator baselines!

The types include:

• Scheduler interface with postTask() and yield() methods
• TaskSignal (extends AbortSignal)
• TaskController (extends AbortController)
• TaskPriority type ("user-blocking" | "user-visible" | "background")
• SchedulerPostTaskOptions and SchedulerPostTaskCallback
• Global scheduler variable

These types are not yet in TypeScript 5.9.3 but should be included in a future release once the lib-generator updates are merged into TypeScript.

As a workaround until then, you can use @types/web package which is also generated from the same lib-generator and may have these types available sooner.

[RyanCavanaugh]

🤖 This is an automated response. I looked for things that might help (duplicates, FAQ entries, etc) but didn't find anything. A human will take a look!

[RyanCavanaugh]

Fixed already in nightly