DOM suggestion: customisable `history.state` type

Search Terms

dom lib window state history any unknown

Suggestion

Currently window.history.state has type any. Could we provide a way for users to customise this type? Perhaps by making it generic or allowing the type to be changed through declaration merging.

Failing that, could we replace the any type with unknown, so we have type safety and users are forced to validate/widen the type?

Another possible solution: if TypeScript provided a way to override any types (https://github.com/microsoft/TypeScript/issues/4062, https://github.com/microsoft/TypeScript/issues/26188).

Also related:

• https://github.com/DefinitelyTyped/DefinitelyTyped/pull/41568
• https://github.com/DefinitelyTyped/DefinitelyTyped/pull/41580

Use Cases

Examples

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

The issue names no files, tests, or concrete entry point. Start by locating the DOM declaration for window.history.state and reviewing the linked related issues; done would require a decided, documented typing design with examples and corresponding tests.