Skip to content

docs: add minimal docs page for type-utils package #9294

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 4 commits into from
Jun 17, 2024
Merged

docs: add minimal docs page for type-utils package #9294

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
744a2d5
docs: add minimal docs page for type-utils package
JoshuaKGoldberg Jun 6, 2024
54bc492
Updated mentions of ts-api-utils and utils
JoshuaKGoldberg Jun 7, 2024
eadcd77
Update docs/packages/Type_Utils.mdx
JoshuaKGoldberg Jun 17, 2024
83cfb48
Merge branch 'main' into docs-page-type-utils
kirkwaiblinger Jun 17, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 20 additions & 0 deletions docs/packages/Type_Utils.mdx
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,20 @@
---
id: type-utils
sidebar_label: type-utils
---

# `@typescript-eslint/type-utils`

<PackageLink packageName="type-utils" scope="@typescript-eslint" />

> Type utilities for working with TypeScript within ESLint rules. ✨

This package contains public utilities for working with TypeScript types that ESLint rules often use.
Rules declared in [`@typescript-eslint/eslint-plugin`](./ESLint_Plugin.mdx) use these utility functions.

The utilities in this package are both:

- More generally ESLint-focused than the broad TypeScript utilities in [`ts-api-utils`](https://npmjs.com/package/ts-api-utils)
- Separated from [`@typescript-eslint/utils`](./Utils.mdx) so that that package does not require a dependency on `typescript`

> See [Custom Rules](../developers/Custom_Rules.mdx) for documentation on creating your own custom ESLint rules for TypeScript code.
33 changes: 24 additions & 9 deletions packages/type-utils/src/builtinSymbolLikes.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,18 +3,24 @@ import * as ts from 'typescript';
import { isSymbolFromDefaultLibrary } from './isSymbolFromDefaultLibrary';

/**
* class Foo extends Promise<number> {}
* Foo.reject
* ^ PromiseLike
* @example
* ```ts
* class DerivedClass extends Promise<number> {}
* DerivedClass.reject
* // ^ PromiseLike
* ```
*/
export function isPromiseLike(program: ts.Program, type: ts.Type): boolean {
return isBuiltinSymbolLike(program, type, 'Promise');
}

/**
* const foo = Promise
* foo.reject
* ^ PromiseConstructorLike
* @example
* ```ts
* const value = Promise
* value.reject
* // ^ PromiseConstructorLike
* ```
*/
export function isPromiseConstructorLike(
program: ts.Program,
Expand All @@ -24,17 +30,23 @@ export function isPromiseConstructorLike(
}

/**
* @example
* ```ts
* class Foo extends Error {}
* new Foo()
* ^ ErrorLike
* // ^ ErrorLike
* ```
*/
export function isErrorLike(program: ts.Program, type: ts.Type): boolean {
return isBuiltinSymbolLike(program, type, 'Error');
}

/**
* @example
* ```ts
* type T = Readonly<Error>
* ^ ReadonlyErrorLike
* // ^ ReadonlyErrorLike
* ```
*/
export function isReadonlyErrorLike(
program: ts.Program,
Expand All @@ -50,8 +62,11 @@ export function isReadonlyErrorLike(
}

/**
* @example
* ```ts
* type T = Readonly<{ foo: 'bar' }>
* ^ ReadonlyTypeLike
* // ^ ReadonlyTypeLike
* ```
*/
export function isReadonlyTypeLike(
program: ts.Program,
Expand Down
1 change: 1 addition & 0 deletions packages/website/sidebars/sidebar.base.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -84,6 +84,7 @@ module.exports = {
'packages/parser',
'packages/rule-tester',
'packages/scope-manager',
'packages/type-utils',
'packages/typescript-estree',
'packages/typescript-eslint',
'packages/utils',
Expand Down