63 lines
1.2 KiB
JavaScript
63 lines
1.2 KiB
JavaScript
/**
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* Takes any input and guarantees an array back.
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*
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* - Converts array-like objects (e.g. `arguments`, `Set`) to a real array.
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* - Converts `undefined` to an empty array.
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* - Converts any another other, singular value (including `null`, objects and iterables other than `Set`) into an array containing that value.
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* - Ignores input which is already an array.
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*
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* @module array-back
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* @example
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* > const arrayify = require('array-back')
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*
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* > arrayify(undefined)
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* []
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*
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* > arrayify(null)
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* [ null ]
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*
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* > arrayify(0)
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* [ 0 ]
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*
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* > arrayify([ 1, 2 ])
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* [ 1, 2 ]
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*
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* > arrayify(new Set([ 1, 2 ]))
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* [ 1, 2 ]
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*
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* > function f(){ return arrayify(arguments); }
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* > f(1,2,3)
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* [ 1, 2, 3 ]
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*/
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function isObject (input) {
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return typeof input === 'object' && input !== null
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}
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function isArrayLike (input) {
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return isObject(input) && typeof input.length === 'number'
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}
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/**
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* @param {*} - The input value to convert to an array
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* @returns {Array}
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* @alias module:array-back
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*/
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function arrayify (input) {
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if (Array.isArray(input)) {
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return input
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}
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if (input === undefined) {
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return []
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}
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if (isArrayLike(input) || input instanceof Set) {
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return Array.from(input)
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}
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return [input]
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}
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export default arrayify
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