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diff --git a/node_modules/@sindresorhus/is/readme.md b/node_modules/@sindresorhus/is/readme.md new file mode 100644 index 0000000..97c023b --- /dev/null +++ b/node_modules/@sindresorhus/is/readme.md @@ -0,0 +1,451 @@ +# is [![Build Status](https://travis-ci.org/sindresorhus/is.svg?branch=master)](https://travis-ci.org/sindresorhus/is) + +> Type check values: `is.string('🦄') //=> true` + +<img src="header.gif" width="182" align="right"> + + +## Install + +``` +$ npm install @sindresorhus/is +``` + + +## Usage + +```js +const is = require('@sindresorhus/is'); + +is('🦄'); +//=> 'string' + +is(new Map()); +//=> 'Map' + +is.number(6); +//=> true +``` + +When using `is` together with TypeScript, [type guards](http://www.typescriptlang.org/docs/handbook/advanced-types.html#type-guards-and-differentiating-types) are being used to infer the correct type inside if-else statements. + +```ts +import is from '@sindresorhus/is'; + +const padLeft = (value: string, padding: string | number) => { + if (is.number(padding)) { + // `padding` is typed as `number` + return Array(padding + 1).join(' ') + value; + } + + if (is.string(padding)) { + // `padding` is typed as `string` + return padding + value; + } + + throw new TypeError(`Expected 'padding' to be of type 'string' or 'number', got '${is(padding)}'.`); +} + +padLeft('🦄', 3); +//=> ' 🦄' + +padLeft('🦄', '🌈'); +//=> '🌈🦄' +``` + + +## API + +### is(value) + +Returns the type of `value`. + +Primitives are lowercase and object types are camelcase. + +Example: + +- `'undefined'` +- `'null'` +- `'string'` +- `'symbol'` +- `'Array'` +- `'Function'` +- `'Object'` + +Note: It will throw an error if you try to feed it object-wrapped primitives, as that's a bad practice. For example `new String('foo')`. + +### is.{method} + +All the below methods accept a value and returns a boolean for whether the value is of the desired type. + +#### Primitives + +##### .undefined(value) +##### .null(value) +##### .string(value) +##### .number(value) +##### .boolean(value) +##### .symbol(value) + +#### Built-in types + +##### .array(value) +##### .function(value) +##### .buffer(value) +##### .object(value) + +Keep in mind that [functions are objects too](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions). + +##### .numericString(value) + +Returns `true` for a string that represents a number. For example, `'42'` and `'-8'`. + +Note: `'NaN'` returns `false`, but `'Infinity'` and `'-Infinity'` return `true`. + +##### .regExp(value) +##### .date(value) +##### .error(value) +##### .nativePromise(value) +##### .promise(value) + +Returns `true` for any object with a `.then()` and `.catch()` method. Prefer this one over `.nativePromise()` as you usually want to allow userland promise implementations too. + +##### .generator(value) + +Returns `true` for any object that implements its own `.next()` and `.throw()` methods and has a function definition for `Symbol.iterator`. + +##### .generatorFunction(value) + +##### .asyncFunction(value) + +Returns `true` for any `async` function that can be called with the `await` operator. + +```js +is.asyncFunction(async () => {}); +// => true + +is.asyncFunction(() => {}); +// => false +``` + +##### .boundFunction(value) + +Returns `true` for any `bound` function. + +```js +is.boundFunction(() => {}); +// => true + +is.boundFunction(function () {}.bind(null)); +// => true + +is.boundFunction(function () {}); +// => false +``` + +##### .map(value) +##### .set(value) +##### .weakMap(value) +##### .weakSet(value) + +#### Typed arrays + +##### .int8Array(value) +##### .uint8Array(value) +##### .uint8ClampedArray(value) +##### .int16Array(value) +##### .uint16Array(value) +##### .int32Array(value) +##### .uint32Array(value) +##### .float32Array(value) +##### .float64Array(value) + +#### Structured data + +##### .arrayBuffer(value) +##### .sharedArrayBuffer(value) +##### .dataView(value) + +#### Emptiness + +##### .emptyString(value) + +Returns `true` if the value is a `string` and the `.length` is 0. + +##### .nonEmptyString(value) + +Returns `true` if the value is a `string` and the `.length` is more than 0. + +##### .emptyStringOrWhitespace(value) + +Returns `true` if `is.emptyString(value)` or if it's a `string` that is all whitespace. + +##### .emptyArray(value) + +Returns `true` if the value is an `Array` and the `.length` is 0. + +##### .nonEmptyArray(value) + +Returns `true` if the value is an `Array` and the `.length` is more than 0. + +##### .emptyObject(value) + +Returns `true` if the value is an `Object` and `Object.keys(value).length` is 0. + +Please note that `Object.keys` returns only own enumerable properties. Hence something like this can happen: + +```js +const object1 = {}; + +Object.defineProperty(object1, 'property1', { + value: 42, + writable: true, + enumerable: false, + configurable: true +}); + +is.emptyObject(object1); +// => true +``` + +##### .nonEmptyObject(value) + +Returns `true` if the value is an `Object` and `Object.keys(value).length` is more than 0. + +##### .emptySet(value) + +Returns `true` if the value is a `Set` and the `.size` is 0. + +##### .nonEmptySet(Value) + +Returns `true` if the value is a `Set` and the `.size` is more than 0. + +##### .emptyMap(value) + +Returns `true` if the value is a `Map` and the `.size` is 0. + +##### .nonEmptyMap(value) + +Returns `true` if the value is a `Map` and the `.size` is more than 0. + +#### Miscellaneous + +##### .directInstanceOf(value, class) + +Returns `true` if `value` is a direct instance of `class`. + +```js +is.directInstanceOf(new Error(), Error); +//=> true + +class UnicornError extends Error {} + +is.directInstanceOf(new UnicornError(), Error); +//=> false +``` + +##### .urlInstance(value) + +Returns `true` if `value` is an instance of the [`URL` class](https://developer.mozilla.org/en-US/docs/Web/API/URL). + +```js +const url = new URL('https://example.com'); + +is.urlInstance(url); +//=> true +``` + +### .url(value) + +Returns `true` if `value` is a URL string. + +Note: this only does basic checking using the [`URL` class](https://developer.mozilla.org/en-US/docs/Web/API/URL) constructor. + +```js +const url = 'https://example.com'; + +is.url(url); +//=> true + +is.url(new URL(url)); +//=> false +``` + +##### .truthy(value) + +Returns `true` for all values that evaluate to true in a boolean context: + +```js +is.truthy('🦄'); +//=> true + +is.truthy(undefined); +//=> false +``` + +##### .falsy(value) + +Returns `true` if `value` is one of: `false`, `0`, `''`, `null`, `undefined`, `NaN`. + +##### .nan(value) +##### .nullOrUndefined(value) +##### .primitive(value) + +JavaScript primitives are as follows: `null`, `undefined`, `string`, `number`, `boolean`, `symbol`. + +##### .integer(value) + +##### .safeInteger(value) + +Returns `true` if `value` is a [safe integer](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/isSafeInteger). + +##### .plainObject(value) + +An object is plain if it's created by either `{}`, `new Object()`, or `Object.create(null)`. + +##### .iterable(value) +##### .asyncIterable(value) +##### .class(value) + +Returns `true` for instances created by a class. + +##### .typedArray(value) + +##### .arrayLike(value) + +A `value` is array-like if it is not a function and has a `value.length` that is a safe integer greater than or equal to 0. + +```js +is.arrayLike(document.forms); +//=> true + +function foo() { + is.arrayLike(arguments); + //=> true +} +foo(); +``` + +##### .inRange(value, range) + +Check if `value` (number) is in the given `range`. The range is an array of two values, lower bound and upper bound, in no specific order. + +```js +is.inRange(3, [0, 5]); +is.inRange(3, [5, 0]); +is.inRange(0, [-2, 2]); +``` + +##### .inRange(value, upperBound) + +Check if `value` (number) is in the range of `0` to `upperBound`. + +```js +is.inRange(3, 10); +``` + +##### .domElement(value) + +Returns `true` if `value` is a DOM Element. + +##### .nodeStream(value) + +Returns `true` if `value` is a Node.js [stream](https://nodejs.org/api/stream.html). + +```js +const fs = require('fs'); + +is.nodeStream(fs.createReadStream('unicorn.png')); +//=> true +``` + +##### .observable(value) + +Returns `true` if `value` is an `Observable`. + +```js +const {Observable} = require('rxjs'); + +is.observable(new Observable()); +//=> true +``` + +##### .infinite(value) + +Check if `value` is `Infinity` or `-Infinity`. + +##### .even(value) + +Returns `true` if `value` is an even integer. + +##### .odd(value) + +Returns `true` if `value` is an odd integer. + +##### .any(predicate, ...values) + +Returns `true` if **any** of the input `values` returns true in the `predicate`: + +```js +is.any(is.string, {}, true, '🦄'); +//=> true + +is.any(is.boolean, 'unicorns', [], new Map()); +//=> false +``` + +##### .all(predicate, ...values) + +Returns `true` if **all** of the input `values` returns true in the `predicate`: + +```js +is.all(is.object, {}, new Map(), new Set()); +//=> true + +is.all(is.string, '🦄', [], 'unicorns'); +//=> false +``` + + +## FAQ + +### Why yet another type checking module? + +There are hundreds of type checking modules on npm, unfortunately, I couldn't find any that fit my needs: + +- Includes both type methods and ability to get the type +- Types of primitives returned as lowercase and object types as camelcase +- Covers all built-ins +- Unsurprising behavior +- Well-maintained +- Comprehensive test suite + +For the ones I found, pick 3 of these. + +The most common mistakes I noticed in these modules was using `instanceof` for type checking, forgetting that functions are objects, and omitting `symbol` as a primitive. + + +## Related + +- [ow](https://github.com/sindresorhus/ow) - Function argument validation for humans +- [is-stream](https://github.com/sindresorhus/is-stream) - Check if something is a Node.js stream +- [is-observable](https://github.com/sindresorhus/is-observable) - Check if a value is an Observable +- [file-type](https://github.com/sindresorhus/file-type) - Detect the file type of a Buffer/Uint8Array +- [is-ip](https://github.com/sindresorhus/is-ip) - Check if a string is an IP address +- [is-array-sorted](https://github.com/sindresorhus/is-array-sorted) - Check if an Array is sorted +- [is-error-constructor](https://github.com/sindresorhus/is-error-constructor) - Check if a value is an error constructor +- [is-empty-iterable](https://github.com/sindresorhus/is-empty-iterable) - Check if an Iterable is empty +- [is-blob](https://github.com/sindresorhus/is-blob) - Check if a value is a Blob - File-like object of immutable, raw data +- [has-emoji](https://github.com/sindresorhus/has-emoji) - Check whether a string has any emoji + + +## Created by + +- [Sindre Sorhus](https://github.com/sindresorhus) +- [Giora Guttsait](https://github.com/gioragutt) +- [Brandon Smith](https://github.com/brandon93s) + + +## License + +MIT |