'use strict'let { existsSync, readFileSync } = require('fs')let { dirname, join } = require('path')let mozilla = require('source-map')function fromBase64(str) {  if (Buffer) {    return Buffer.from(str, 'base64').toString()  } else {    // istanbul ignore next    return window.atob(str)  }}class PreviousMap {  constructor(css, opts) {    if (opts.map === false) return    this.loadAnnotation(css)    this.inline = this.startWith(this.annotation, 'data:')    let prev = opts.map ? opts.map.prev : undefined    let text = this.loadMap(opts.from, prev)    if (!this.mapFile && opts.from) {      this.mapFile = opts.from    }    if (this.mapFile) this.root = dirname(this.mapFile)    if (text) this.text = text  }  consumer() {    if (!this.consumerCache) {      this.consumerCache = new mozilla.SourceMapConsumer(this.text)    }    return this.consumerCache  }  withContent() {    return !!(      this.consumer().sourcesContent &&      this.consumer().sourcesContent.length > 0    )  }  startWith(string, start) {    if (!string) return false    return string.substr(0, start.length) === start  }  getAnnotationURL(sourceMapString) {    return sourceMapString      .match(/\/\*\s*# sourceMappingURL=(.*)\s*\*\//)[1]      .trim()  }  loadAnnotation(css) {    // BUG: NVD-CWE-noinfo Insufficient Information    // let annotations = css.match(/\/\*\s*# sourceMappingURL=.*\s*\*\//gm)    // FIXED:    let annotations = css.match(/\/\*\s*# sourceMappingURL=.*\*\//gm)    if (annotations && annotations.length > 0) {      // Locate the last sourceMappingURL to avoid picking up      // sourceMappingURLs from comments, strings, etc.      let lastAnnotation = annotations[annotations.length - 1]      if (lastAnnotation) {        this.annotation = this.getAnnotationURL(lastAnnotation)      }    }  }  decodeInline(text) {    let baseCharsetUri = /^data:application\/json;charset=utf-?8;base64,/    let baseUri = /^data:application\/json;base64,/    let charsetUri = /^data:application\/json;charset=utf-?8,/    let uri = /^data:application\/json,/    if (charsetUri.test(text) || uri.test(text)) {      return decodeURIComponent(text.substr(RegExp.lastMatch.length))    }    if (baseCharsetUri.test(text) || baseUri.test(text)) {      return fromBase64(text.substr(RegExp.lastMatch.length))    }    let encoding = text.match(/data:application\/json;([^,]+),/)[1]    throw new Error('Unsupported source map encoding ' + encoding)  }  loadFile(path) {    this.root = dirname(path)    if (existsSync(path)) {      this.mapFile = path      return readFileSync(path, 'utf-8').toString().trim()    }  }  loadMap(file, prev) {    if (prev === false) return false    if (prev) {      if (typeof prev === 'string') {        return prev      } else if (typeof prev === 'function') {        let prevPath = prev(file)        if (prevPath) {          let map = this.loadFile(prevPath)          if (!map) {            throw new Error(              'Unable to load previous source map: ' + prevPath.toString()            )          }          return map        }      } else if (prev instanceof mozilla.SourceMapConsumer) {        return mozilla.SourceMapGenerator.fromSourceMap(prev).toString()      } else if (prev instanceof mozilla.SourceMapGenerator) {        return prev.toString()      } else if (this.isMap(prev)) {        return JSON.stringify(prev)      } else {        throw new Error(          'Unsupported previous source map format: ' + prev.toString()        )      }    } else if (this.inline) {      return this.decodeInline(this.annotation)    } else if (this.annotation) {      let map = this.annotation      if (file) map = join(dirname(file), map)      return this.loadFile(map)    }  }  isMap(map) {    if (typeof map !== 'object') return false    return (      typeof map.mappings === 'string' ||      typeof map._mappings === 'string' ||      Array.isArray(map.sections)    )  }}module.exports = PreviousMapPreviousMap.default = PreviousMap