34 lines
843 B
JavaScript
34 lines
843 B
JavaScript
'use strict'
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const { sep: DEFAULT_SEPARATOR } = require('path')
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const determineSeparator = paths => {
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for (const path of paths) {
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const match = /(\/|\\)/.exec(path)
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if (match !== null) return match[0]
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}
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return DEFAULT_SEPARATOR
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}
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module.exports = function commonPathPrefix (paths, sep = determineSeparator(paths)) {
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const [first = '', ...remaining] = paths
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if (first === '' || remaining.length === 0) return ''
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const parts = first.split(sep)
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let endOfPrefix = parts.length
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for (const path of remaining) {
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const compare = path.split(sep)
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for (let i = 0; i < endOfPrefix; i++) {
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if (compare[i] !== parts[i]) {
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endOfPrefix = i
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}
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}
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if (endOfPrefix === 0) return ''
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}
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const prefix = parts.slice(0, endOfPrefix).join(sep)
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return prefix.endsWith(sep) ? prefix : prefix + sep
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}
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