diff options
author | cjihrig <cjihrig@gmail.com> | 2019-11-22 14:17:22 -0500 |
---|---|---|
committer | cjihrig <cjihrig@gmail.com> | 2019-11-25 11:55:40 -0500 |
commit | 90fb308de42575adeed82d864da57148049185b3 (patch) | |
tree | 79d362bf7f18f1088da78b8b3073252b059b7c3f /tools/node_modules/eslint/node_modules/type-fest | |
parent | 02d4c742369975fd7499bb242be61bbb1f8fc1ab (diff) | |
download | node-new-90fb308de42575adeed82d864da57148049185b3.tar.gz |
tools: update ESLint to 6.7.1
Update ESLint to 6.7.1
PR-URL: https://github.com/nodejs/node/pull/30598
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Diffstat (limited to 'tools/node_modules/eslint/node_modules/type-fest')
-rw-r--r-- | tools/node_modules/eslint/node_modules/type-fest/package.json | 11 | ||||
-rw-r--r-- | tools/node_modules/eslint/node_modules/type-fest/readme.md | 531 |
2 files changed, 530 insertions, 12 deletions
diff --git a/tools/node_modules/eslint/node_modules/type-fest/package.json b/tools/node_modules/eslint/node_modules/type-fest/package.json index a5a398048d..0164025631 100644 --- a/tools/node_modules/eslint/node_modules/type-fest/package.json +++ b/tools/node_modules/eslint/node_modules/type-fest/package.json @@ -11,14 +11,15 @@ "deprecated": false, "description": "A collection of essential TypeScript types", "devDependencies": { - "@sindresorhus/tsconfig": "^0.3.0", - "@typescript-eslint/eslint-plugin": "^1.8.0", - "eslint-config-xo-typescript": "^0.11.0", + "@sindresorhus/tsconfig": "^0.4.0", + "@typescript-eslint/eslint-plugin": "^2.2.0", + "@typescript-eslint/parser": "^2.2.0", + "eslint-config-xo-typescript": "^0.18.0", "tsd": "^0.7.3", "xo": "^0.24.0" }, "engines": { - "node": ">=6" + "node": ">=8" }, "files": [ "index.d.ts", @@ -45,7 +46,7 @@ "scripts": { "test": "xo && tsd" }, - "version": "0.5.2", + "version": "0.8.1", "xo": { "extends": "xo-typescript", "extensions": [ diff --git a/tools/node_modules/eslint/node_modules/type-fest/readme.md b/tools/node_modules/eslint/node_modules/type-fest/readme.md index 3f11c3c1ed..1824bdabed 100644 --- a/tools/node_modules/eslint/node_modules/type-fest/readme.md +++ b/tools/node_modules/eslint/node_modules/type-fest/readme.md @@ -36,14 +36,14 @@ $ npm install type-fest ## Usage ```ts -import {Omit} from 'type-fest'; +import {Except} from 'type-fest'; type Foo = { unicorn: string; rainbow: boolean; }; -type FooWithoutRainbow = Omit<Foo, 'rainbow'>; +type FooWithoutRainbow = Except<Foo, 'rainbow'>; //=> {unicorn: string} ``` @@ -64,13 +64,19 @@ Click the type names for complete docs. ### Utilities -- [`Omit`](source/omit.d.ts) - Create a type from an object type without certain keys. -- [`Mutable`](source/mutable.d.ts) - Convert an object with `readonly` properties into a mutable object. Inverse of `Readonly<T>`. +- [`Except`](source/except.d.ts) - Create a type from an object type without certain keys. This is a stricter version of [`Omit`](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-5.html#the-omit-helper-type). +- [`Mutable`](source/mutable.d.ts) - Convert an object with `readonly` keys into a mutable object. The inverse of `Readonly<T>`. - [`Merge`](source/merge.d.ts) - Merge two types into a new type. Keys of the second type overrides keys of the first type. -- [`MergeExclusive`](source/merge-exclusive.d.ts) - Create a type that has mutually exclusive properties. -- [`RequireAtLeastOne`](source/require-at-least-one.d.ts) - Create a type that requires at least one of the given properties. -- [`ReadonlyDeep`](source/readonly-deep.d.ts) - Create a deeply immutable version of a `object`/`Map`/`Set`/`Array` type. +- [`MergeExclusive`](source/merge-exclusive.d.ts) - Create a type that has mutually exclusive keys. +- [`RequireAtLeastOne`](source/require-at-least-one.d.ts) - Create a type that requires at least one of the given keys. +- [`RequireExactlyOne`](source/require-one.d.ts) - Create a type that requires exactly a single key of the given keys and disallows more. +- [`PartialDeep`](source/partial-deep.d.ts) - Create a deeply optional version of another type. Use [`Partial<T>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1401-L1406) if you only need one level deep. +- [`ReadonlyDeep`](source/readonly-deep.d.ts) - Create a deeply immutable version of an `object`/`Map`/`Set`/`Array` type. Use [`Readonly<T>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1415-L1420) if you only need one level deep. - [`LiteralUnion`](source/literal-union.d.ts) - Create a union type by combining primitive types and literal types without sacrificing auto-completion in IDEs for the literal type part of the union. Workaround for [Microsoft/TypeScript#29729](https://github.com/Microsoft/TypeScript/issues/29729). +- [`Promisable`](source/promisable.d.ts) - Create a type that represents either the value or the value wrapped in `PromiseLike`. +- [`Opaque`](source/opaque.d.ts) - Create an [opaque type](https://codemix.com/opaque-types-in-javascript/). +- [`SetOptional`](source/set-optional.d.ts) - Create a type that makes the given keys optional. +- [`SetRequired`](source/set-required.d.ts) - Create a type that makes the given keys required. ### Miscellaneous @@ -82,6 +88,7 @@ Click the type names for complete docs. *If we decline a type addition, we will make sure to document the better solution here.* - [`Diff` and `Spread`](https://github.com/sindresorhus/type-fest/pull/7) - The PR author didn't provide any real-world use-cases and the PR went stale. If you think this type is useful, provide some real-world use-cases and we might reconsider. +- [`Dictionary`](https://github.com/sindresorhus/type-fest/issues/33) - You only save a few characters (`Dictionary<number>` vs `Record<string, number>`) from [`Record`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1429-L1434), which is more flexible and well-known. Also, you shouldn't use an object as a dictionary. We have `Map` in JavaScript now. ## Tips @@ -91,17 +98,514 @@ Click the type names for complete docs. There are many advanced types most users don't know about. - [`Partial<T>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1401-L1406) - Make all properties in `T` optional. + <details> + <summary> + Example + </summary> + + [Playground](https://typescript-play.js.org/?target=6#code/KYOwrgtgBAMg9gcxsAbsANlA3gKClAeQDMiAaPKAEWACMwFz8BRAJxbhcagDEBDAF17ocAXxw4AliH7AWRXgGNgUAHJwAJsADCcEEQkJsFXgAcTK3hGAAuKAGd+LKQgDcFEx363wEGrLf46IjIaOi28EioGG5iOArovHZ2qhrAAIJmAEJgEuiaLEb4Jk4oAsoKuvoIYCwCErq2apo6egZQALyF+FCm5pY2UABETelmg1xFnrYAzAAM8xNQQZGh4cFR6AB0xEQUIm4UFa0IABRHVbYACrws-BJCADwjLVUAfACUXfhEHFBnug4oABrYAATygcCIhBoACtgAp+JsQaC7P9ju9Prhut0joCwCZ1GUAGpCMDKTrnAwAbWRPWSyMhKWalQMAF0Dtj8BIoSd8YSZCT0GSOu1OmAQJp9CBgOpPkc7uBgBzOfwABYSOybSnVWp3XQ0sF04FgxnPFkIVkdKB84mkpUUfCxbEsYD8GogKBqjUBKBiWIAen9UGut3u6CeqReBlePXQQQA7skwMl+HAoMU4CgJJoISB0ODeOmbvwIVC1cAcIGmdpzVApDI5IpgJscNL49WMiZsrl8id3lrzScsD0zBYrLZBgAVOCUOCdwa+95uIA) + + ```ts + interface NodeConfig { + appName: string; + port: number; + } + + class NodeAppBuilder { + private configuration: NodeConfig = { + appName: 'NodeApp', + port: 3000 + }; + + config(config: Partial<NodeConfig>) { + type NodeConfigKey = keyof NodeConfig; + + for (const key of Object.keys(config) as NodeConfigKey[]) { + const updateValue = config[key]; + + if (updateValue === undefined) { + continue; + } + + this.configuration[key] = updateValue; + } + + return this; + } + } + + // `Partial<NodeConfig>`` allows us to provide only a part of the + // NodeConfig interface. + new NodeAppBuilder().config({appName: 'ToDoApp'}); + ``` + </details> + - [`Required<T>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1408-L1413) - Make all properties in `T` required. + <details> + <summary> + Example + </summary> + + [Playground](https://typescript-play.js.org/?target=6#code/AQ4SwOwFwUwJwGYEMDGNgGED21VQGJZwC2wA3gFCjXAzFJgA2A-AFzADOUckA5gNxUaIYjA4ckvGG07c+g6gF8KQkAgCuEFFDA5O6gEbEwUbLm2ESwABQIixACJIoSdgCUYAR3Vg4MACYAPGYuFvYAfACU5Ko0APRxwADKMBD+wFAAFuh2Vv7OSBlYGdmc8ABu8LHKsRyGxqY4oQT21pTCIHQMjOwA5DAAHgACxAAOjDAAdChYxL0ANLHUouKSMH0AEmAAhJhY6ozpAJ77GTCMjMCiV0ToSAb7UJPPC9WRgrEJwAAqR6MwSRQPFGUFocDgRHYxnEfGAowh-zgUCOwF6KwkUl6tXqJhCeEsxDaS1AXSYfUGI3GUxmc0WSneQA) + + ```ts + interface ContactForm { + email?: string; + message?: string; + } + + function submitContactForm(formData: Required<ContactForm>) { + // Send the form data to the server. + } + + submitContactForm({ + email: 'ex@mple.com', + message: 'Hi! Could you tell me more about…', + }); + + // TypeScript error: missing property 'message' + submitContactForm({ + email: 'ex@mple.com', + }); + ``` + </details> + - [`Readonly<T>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1415-L1420) - Make all properties in `T` readonly. + <details> + <summary> + Example + </summary> + + [Playground](https://typescript-play.js.org/?target=6#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) + + ```ts + enum LogLevel { + Off, + Debug, + Error, + Fatal + }; + + interface LoggerConfig { + name: string; + level: LogLevel; + } + + class Logger { + config: Readonly<LoggerConfig>; + + constructor({name, level}: LoggerConfig) { + this.config = {name, level}; + Object.freeze(this.config); + } + } + + const config: LoggerConfig = { + name: 'MyApp', + level: LogLevel.Debug + }; + + const logger = new Logger(config); + + // TypeScript Error: cannot assign to read-only property. + logger.config.level = LogLevel.Error; + + // We are able to edit config variable as we please. + config.level = LogLevel.Error; + ``` + </details> + - [`Pick<T, K>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1422-L1427) - From `T`, pick a set of properties whose keys are in the union `K`. + <details> + <summary> + Example + </summary> + + [Playground](https://typescript-play.js.org/?target=6#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) + + ```ts + interface Article { + title: string; + thumbnail: string; + content: string; + } + + // Creates new type out of the `Article` interface composed + // from the Articles' two properties: `title` and `thumbnail`. + // `ArticlePreview = {title: string; thumbnail: string}` + type ArticlePreview = Pick<Article, 'title' | 'thumbnail'>; + + // Render a list of articles using only title and description. + function renderArticlePreviews(previews: ArticlePreview[]): HTMLElement { + const articles = document.createElement('div'); + + for (const preview of previews) { + // Append preview to the articles. + } + + return articles; + } + + const articles = renderArticlePreviews([ + { + title: 'TypeScript tutorial!', + thumbnail: '/assets/ts.jpg' + } + ]); + ``` + </details> + - [`Record<K, T>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1429-L1434) - Construct a type with a set of properties `K` of type `T`. + <details> + <summary> + Example + </summary> + + [Playground](https://typescript-play.js.org/?target=6#code/AQ4ejYAUHsGcCWAXBMB2dgwGbAKYC2ADgDYwCeeemCaWArgE7ADGMxAhmuQHQBQoYEnJE8wALKEARnkaxEKdMAC8wAOS0kstGuAAfdQBM8ANzxlRjXQbVaWACwC0JPB0NqA3HwGgIwAJJoWozYHCxixnAsjAhStADmwESMMJYo1Fi4HMCIaPEu+MRklHj8gpqyoeHAAKJFFFTAAN4+giDYCIxwSAByHAR4AFw5SDF5Xm2gJBzdfQPD3WPxE5PAlBxdAPLYNQAelgh4aOHDaPQEMowrIAC+3oJ+AMKMrlrAXFhSAFZ4LEhC9g4-0BmA4JBISXgiCkBQABpILrJ5MhUGhYcATGD6Bk4Hh-jNgABrPDkOBlXyQAAq9ngYmJpOAAHcEOCRjAXqwYODfoo6DhakUSph+Uh7GI4P0xER4Cj0OSQGwMP8tP1hgAlX7swwAHgRl2RvIANALSA08ABtAC6AD4VM1Wm0Kow0MMrYaHYJjGYLLJXZb3at1HYnC43Go-QHQDcvA6-JsmEJXARgCDgMYWAhjIYhDAU+YiMAAFIwex0ZmilMITCGF79TLAGRsAgJYAAZRwSEZGzEABFTOZUrJ5Yn+jwnWgeER6HB7AAKJrADpdXqS4ZqYultTG6azVfqHswPBbtauLY7fayQ7HIbAAAMwBuAEoYw9IBq2Ixs9h2eFMOQYPQObALQKJgggABeYhghCIpikkKRpOQRIknAsZUiIeCttECBEP8NSMCkjDDAARMGziuIYxHwYOjDCMBmDNnAuTxA6irdCOBB1Lh5Dqpqn66tISIykawBnOCtqqC0gbjqc9DgpGkxegOliyfJDrRkAA) + + ```ts + // Positions of employees in our company. + type MemberPosition = 'intern' | 'developer' | 'tech-lead'; + + // Interface describing properties of a single employee. + interface Employee { + firstName: string; + lastName: string; + yearsOfExperience: number; + } + + // Create an object that has all possible `MemberPosition` values set as keys. + // Those keys will store a collection of Employees of the same position. + const team: Record<MemberPosition, Employee[]> = { + intern: [], + developer: [], + 'tech-lead': [], + }; + + // Our team has decided to help John with his dream of becoming Software Developer. + team.intern.push({ + firstName: 'John', + lastName: 'Doe', + yearsOfExperience: 0 + }); + + // `Record` forces you to initialize all of the property keys. + // TypeScript Error: "tech-lead" property is missing + const teamEmpty: Record<MemberPosition, null> = { + intern: null, + developer: null, + }; + ``` + </details> + - [`Exclude<T, U>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1436-L1439) - Exclude from `T` those types that are assignable to `U`. + <details> + <summary> + Example + </summary> + + [Playground](https://typescript-play.js.org/?target=6#code/JYOwLgpgTgZghgYwgAgMrQG7QMIHsQzADmyA3gFDLIAOuUYAXMiAK4A2byAPsgM5hRQJHqwC2AI2gBucgF9y5MAE9qKAEoQAjiwj8AEnBAATNtGQBeZAAooWphu26wAGmS3e93bRC8IASgsAPmRDJRlyAHoI5ABRAA8ENhYjFFYOZGVVZBgoXFFkAAM0zh5+QRBhZhYJaAKAOkjogEkQZAQ4X2QAdwALCFbaemRgXmQtFjhOMFwq9K6ULuB0lk6U+HYwZAxJnQaYFhAEMGB8ZCIIMAAFOjAANR2IK0HGWISklIAedCgsKDwCYgAbQA5M9gQBdVzFQJ+JhiSRQMiUYYwayZCC4VHPCzmSzAspCYEBWxgFhQAZwKC+FpgJ43VwARgADH4ZFQSWSBjcZPJyPtDsdTvxKWBvr8rD1DCZoJ5HPopaYoK4EPhCEQmGKcKriLCtrhgEYkVQVT5Nr4fmZLLZtMBbFZgT0wGBqES6ghbHBIJqoBKFdBWQpjfh+DQbhY2tqiHVsbjLMVkAB+ZAAZiZaeQTHOVxu9ySjxNaujNwDVHNvzqbBGkBAdPoAfkQA) + + ```ts + interface ServerConfig { + port: null | string | number; + } + + type RequestHandler = (request: Request, response: Response) => void; + + // Exclude `null` type from `null | string | number`. + // In case the port is equal to `null`, we will use default value. + function getPortValue(port: Exclude<ServerConfig['port'], null>): number { + if (typeof port === 'string') { + return parseInt(port, 10); + } + + return port; + } + + function startServer(handler: RequestHandler, config: ServerConfig): void { + const server = require('http').createServer(handler); + + const port = config.port === null ? 3000 : getPortValue(config.port); + server.listen(port); + } + ``` + </details> + - [`Extract<T, U>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1441-L1444) - Extract from `T` those types that are assignable to `U`. + <details> + <summary> + Example + </summary> + + [Playground](https://typescript-play.js.org/?target=6#code/CYUwxgNghgTiAEAzArgOzAFwJYHtXzSwEdkQBJYACgEoAueVZAWwCMQYBuAKDDwGcM8MgBF4AXngBlAJ6scESgHIRi6ty5ZUGdoihgEABXZ888AN5d48ANoiAuvUat23K6ihMQ9ATE0BzV3goPy8GZjZOLgBfLi4Aejj4AEEICBwAdz54MAALKFQQ+BxEeAAHY1NgKAwoIKy0grr4DByEUpgccpgMaXgAaxBerCzi+B9-ZulygDouFHRsU1z8kKMYE1RhaqgAHkt4AHkWACt4EAAPbVRgLLWNgBp9gGlBs8uQa6yAUUuYPQwdgNpKM7nh7mMML4CgA+R5WABqUAgpDeVxuhxO1he0jsXGh8EoOBO9COx3BQPo2PBADckaR6IjkSA6PBqTgsMBzPsicdrEC7OJWXSQNwYvFEgAVTS9JLXODpeDpKBZFg4GCoWa8VACIJykAKiQWKy2YQOAioYikCg0OEMDyhRSy4DyxS24KhAAMjyi6gS8AAwjh5OD0iBFHAkJoEOksC1mnkMJq8gUQKDNttKPlnfrwYp3J5XfBHXqoKpfYkAOI4ansTxaeDADmoRSCCBYAbxhC6TDx6rwYHIRX5bScjA4bLJwoDmDwDkfbA9JMrVMVdM1TN69LgkTgwgkchUahqIA) + + ```ts + declare function uniqueId(): number; + + const ID = Symbol('ID'); + + interface Person { + [ID]: number; + name: string; + age: number; + } + + // Allows changing the person data as long as the property key is of string type. + function changePersonData< + Obj extends Person, + Key extends Extract<keyof Person, string>, + Value extends Obj[Key] + > (obj: Obj, key: Key, value: Value): void { + obj[key] = value; + } + + // Tiny Andrew was born. + const andrew = { + [ID]: uniqueId(), + name: 'Andrew', + age: 0, + }; + + // Cool, we're fine with that. + changePersonData(andrew, 'name', 'Pony'); + + // Goverment didn't like the fact that you wanted to change your identity. + changePersonData(andrew, ID, uniqueId()); + ``` + </details> + - [`NonNullable<T>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1446-L1449) - Exclude `null` and `undefined` from `T`. + <details> + <summary> + Example + </summary> + Works with <code>strictNullChecks</code> set to <code>true</code>. (Read more <a href="https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-0.html">here</a>) + + [Playground](https://typescript-play.js.org/?target=6#code/C4TwDgpgBACg9gJ2AOQK4FsBGEFQLxQDOwCAlgHYDmUAPlORtrnQwDasDcAUFwPQBU-WAEMkUOADMowqAGNWwwoSgATCBIqlgpOOSjAAFsOBRSy1IQgr9cKJlSlW1mZYQA3HFH68u8xcoBlHA8EACEHJ08Aby4oKDBUTFZSWXjEFEYcAEIALihkXTR2YSSIAB54JDQsHAA+blj4xOTUsHSACkMzPKD3HHDHNQQAGjSkPMqMmoQASh7g-oihqBi4uNIpdraxPAI2VhmVxrX9AzMAOm2ppnwoAA4ABifuE4BfKAhWSyOTuK7CS7pao3AhXF5rV48E4ICDAVAIPT-cGQyG+XTEIgLMJLTx7CAAdygvRCA0iCHaMwarhJOIQjUBSHaACJHk8mYdeLwxtdcVAAOSsh58+lXdr7Dlcq7A3n3J4PEUdADMcspUE53OluAIUGVTx46oAKuAIAFZGQwCYAKIIBCILjUxaDHAMnla+iodjcIA) + + ```ts + type PortNumber = string | number | null; + + /** Part of a class definition that is used to build a server */ + class ServerBuilder { + portNumber!: NonNullable<PortNumber>; + + port(this: ServerBuilder, port: PortNumber): ServerBuilder { + if (port == null) { + this.portNumber = 8000; + } else { + this.portNumber = port; + } + + return this; + } + } + + const serverBuilder = new ServerBuilder(); + + serverBuilder + .port('8000') // portNumber = '8000' + .port(null) // portNumber = 8000 + .port(3000); // portNumber = 3000 + + // TypeScript error + serverBuilder.portNumber = null; + ``` + </details> + - [`Parameters<T>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1451-L1454) - Obtain the parameters of a function type in a tuple. + <details> + <summary> + Example + </summary> + + [Playground](https://typescript-play.js.org/?target=6#code/GYVwdgxgLglg9mABAZwBYmMANgUwBQxgAOIUAXIgIZgCeA2gLoCUFAbnDACaIDeAUIkQB6IYgCypSlBxUATrMo1ECsJzgBbLEoipqAc0J7EMKMgDkiHLnU4wp46pwAPHMgB0fAL58+oSLARECEosLAA5ABUYG2QAHgAxJGdpVWREPDdMylk9ZApqemZEAF4APipacrw-CApEgBogkKwAYThwckQwEHUAIxxZJl4BYVEImiIZKF0oZRwiWVdbeygJmThgOYgcGFYcbhqApCJsyhtpWXcR1cnEePBoeDAABVPzgbTixFeFd8uEsClADcIxGiygIFkSEOT3SmTc2VydQeRx+ZxwF2QQ34gkEwDgsnSuFmMBKiAADEDjIhYk1Qm0OlSYABqZnYka4xA1DJZHJYkGc7yCbyeRA+CAIZCzNAYbA4CIAdxg2zJwVCkWirjwMswuEaACYmCCgA) + + ```ts + function shuffle(input: any[]): void { + // Mutate array randomly changing its' elements indexes. + } + + function callNTimes<Fn extends (...args: any[]) => any> (func: Fn, callCount: number) { + // Type that represents the type of the received function parameters. + type FunctionParameters = Parameters<Fn>; + + return function (...args: FunctionParameters) { + for (let i = 0; i < callCount; i++) { + func(...args); + } + } + } + + const shuffleTwice = callNTimes(shuffle, 2); + ``` + </details> + - [`ConstructorParameters<T>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1456-L1459) - Obtain the parameters of a constructor function type in a tuple. + <details> + <summary> + Example + </summary> + + [Playground](https://typescript-play.js.org/?target=6#code/MYGwhgzhAECCBOAXAlqApgWQPYBM0mgG8AoaaFRENALmgkXmQDsBzAblOmCycTV4D8teo1YdO3JiICuwRFngAKClWENmLAJRFOZRAAtkEAHQq00ALzlklNBzIBfYk+KhIMAJJTEYJsDQAwmDA+mgAPAAq0GgAHnxMODCKTGgA7tCKxllg8CwQtL4AngDaALraFgB80EWa1SRkAA6MAG5gfNAB4FABPDJyCrQR9tDNyG0dwMGhtBhgjWEiGgA00F70vv4RhY3hEZXVVinpc42KmuJkkv3y8Bly8EPaDWTkhiZd7r3e8LK3llwGCMXGQWGhEOsfH5zJlsrl8p0+gw-goAAo5MAAW3BaHgEEilU0tEhmzQ212BJ0ry4SOg+kg+gBBiMximIGA0nAfAQLGk2N4EAAEgzYcYcnkLsRdDTvNEYkYUKwSdCme9WdM0MYwYhFPSIPpJdTkAAzDKxBUaZX+aAAQgsVmkCTQxuYaBw2ng4Ok8CYcotSu8pMur09iG9vuObxZnx6SN+AyUWTF8MN0CcZE4Ywm5jZHK5aB5fP4iCFIqT4oRRTKRLo6lYVNeAHpG50wOzOe1zHr9NLQ+HoABybsD4HOKXXRA1JCoKhBELmI5pNaB6Fz0KKBAodDYPAgSUTmqYsAALx4m5nC6nW9nGq14KtaEUA9gR9PvuNCjQ9BgACNvcwNBtAcLiAA) + + ```ts + class ArticleModel { + title: string; + content?: string; + + constructor(title: string) { + this.title = title; + } + } + + class InstanceCache<T extends (new (...args: any[]) => any)> { + private ClassConstructor: T; + private cache: Map<string, InstanceType<T>> = new Map(); + + constructor (ctr: T) { + this.ClassConstructor = ctr; + } + + getInstance (...args: ConstructorParameters<T>): InstanceType<T> { + const hash = this.calculateArgumentsHash(...args); + + const existingInstance = this.cache.get(hash); + if (existingInstance !== undefined) { + return existingInstance; + } + + return new this.ClassConstructor(...args); + } + + private calculateArgumentsHash(...args: any[]): string { + // Calculate hash. + return 'hash'; + } + } + + const articleCache = new InstanceCache(ArticleModel); + const amazonArticle = articleCache.getInstance('Amazon forests burining!'); + ``` + </details> + - [`ReturnType<T>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1461-L1464) – Obtain the return type of a function type. + <details> + <summary> + Example + </summary> + + [Playground](https://typescript-play.js.org/?target=6#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-YhAA+qegAAYLKQLQj3ZsEsdccmnGcLor2Dn8xGedHGpEIBzEzspfsfMHDNAANTQACMVaIljV5GQkRA5DYmIpVKQAgAJARO9le33BDXIyi0YuLW2nJFGLqkOvxFB0YPdBSaLZ0IwNzyPkO8-xkGgsLh8Al427a3hWAhXwwHA8EHT5PmgAB1bAQBAANJ24adKWpft72RaBUTgRBUCAj89HAM8xCTaBjggABRQx0DuHJv25P9dCkWRZVIAAiBjoFImpmjlFBgA0NpsjadByDacgIDAEAIAAQmYpjoGYgAZSBsmGPw6DtZiiFA8CoJguDmAQmoZ2QvtUKQLdoAYmBTwgdEiCAA) + + ```ts + /** Provides every element of the iterable `iter` into the `callback` function and stores the results in an array. */ + function mapIter< + Elem, + Func extends (elem: Elem) => any, + Ret extends ReturnType<Func> + >(iter: Iterable<Elem>, callback: Func): Ret[] { + const mapped: Ret[] = []; + + for (const elem of iter) { + mapped.push(callback(elem)); + } + + return mapped; + } + + const setObject: Set<string> = new Set(); + const mapObject: Map<number, string> = new Map(); + + mapIter(setObject, (value: string) => value.indexOf('Foo')); // number[] + + mapIter(mapObject, ([key, value]: [number, string]) => { + return key % 2 === 0 ? value : 'Odd'; + }); // string[] + ``` + </details> + - [`InstanceType<T>`](https://github.com/Microsoft/TypeScript/blob/2961bc3fc0ea1117d4e53bc8e97fa76119bc33e3/src/lib/es5.d.ts#L1466-L1469) – Obtain the instance type of a constructor function type. + <details> + <summary> + Example + </summary> + + [Playground](https://typescript-play.js.org/?target=6#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-YhAA+qegAAYLKQLQj3ZsEsdccmnGcLor2Dn8xGedHGpEIBzEzspfsfMHDNAANTQACMVaIljV5GQkRA5DYmIpVKQAgAJARO9le33BDXIyi0YuLW2nJFGLqkOvxFB0YPdBSaLZ0IwNzyPkO8-xkGgsLh8Al427a3hWAhXwwHA8EHT5PmgAB1bAQBAANJ24adKWpft72RaBUTgRBUCAj89HAM8xCTaBjggABRQx0DuHJv25P9dCkWRZVIAAiBjoFImpmjlFBgA0NpsjadByDacgIDAEAIAAQmYpjoGYgAZSBsmGPw6DtZiiFA8CoJguDmAQmoZ2QvtUKQLdoAYmBTwgdEiCAA) + + ```ts + class IdleService { + doNothing (): void {} + } + + class News { + title: string; + content: string; + + constructor(title: string, content: string) { + this.title = title; + this.content = content; + } + } + + const instanceCounter: Map<Function, number> = new Map(); + + interface Constructor { + new(...args: any[]): any; + } + + // Keep track how many instances of `Constr` constructor have been created. + function getInstance< + Constr extends Constructor, + Args extends ConstructorParameters<Constr> + >(constructor: Constr, ...args: Args): InstanceType<Constr> { + let count = instanceCounter.get(constructor) || 0; + + const instance = new constructor(...args); + + instanceCounter.set(constructor, count + 1); + + console.log(`Created ${count + 1} instances of ${Constr.name} class`); + + return instance; + } + + + const idleService = getInstance(IdleService); + // Will log: `Created 1 instances of IdleService class` + const newsEntry = getInstance(News, 'New ECMAScript proposals!', 'Last month...'); + // Will log: `Created 1 instances of News class` + ``` + </details> + +- [`Omit<T, K>`](https://github.com/microsoft/TypeScript/blob/71af02f7459dc812e85ac31365bfe23daf14b4e4/src/lib/es5.d.ts#L1446) – Constructs a type by picking all properties from T and then removing K. + <details> + <summary> + Example + </summary> + + [Playground](https://typescript-play.js.org/?target=6#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-SgfXlHqVUE4xiAA) + + ```ts + interface Animal { + imageUrl: string; + species: string; + images: string[]; + paragraphs: string[]; + } + + // Creates new type with all properties of the `Animal` interface + // except 'images' and 'paragraphs' properties. We can use this + // type to render small hover tooltip for a wiki entry list. + type AnimalShortInfo = Omit<Animal, 'images' | 'paragraphs'>; + + function renderAnimalHoverInfo (animals: AnimalShortInfo[]): HTMLElement { + const container = document.createElement('div'); + // Internal implementation. + return container; + } + ``` + </details> You can find some examples in the [TypeScript docs](https://www.typescriptlang.org/docs/handbook/advanced-types.html#predefined-conditional-types). @@ -116,3 +620,16 @@ You can find some examples in the [TypeScript docs](https://www.typescriptlang.o ## License (MIT OR CC0-1.0) + + +--- + +<div align="center"> + <b> + <a href="https://tidelift.com/subscription/pkg/npm-type-fest?utm_source=npm-type-fest&utm_medium=referral&utm_campaign=readme">Get professional support for this package with a Tidelift subscription</a> + </b> + <br> + <sub> + Tidelift helps make open source sustainable for maintainers while giving companies<br>assurances about security, maintenance, and licensing for their dependencies. + </sub> +</div> |