algorithms/node_modules/source-map-resolve/source-map-resolve.js

// Copyright 2014, 2015, 2016, 2017 Simon Lydell
// X11 (“MIT”) Licensed. (See LICENSE.)

// Note: source-map-resolve.js is generated from source-map-resolve-node.js and
// source-map-resolve-template.js. Only edit the two latter files, _not_
// source-map-resolve.js!

void (function(root, factory) {
  if (typeof define === "function" && define.amd) {
    define(["source-map-url", "resolve-url"], factory)
  } else if (typeof exports === "object") {
    var sourceMappingURL = require("source-map-url")
    var resolveUrl = require("resolve-url")
    module.exports = factory(sourceMappingURL, resolveUrl)
  } else {
    root.sourceMapResolve = factory(root.sourceMappingURL, root.resolveUrl)
  }
}(this, function(sourceMappingURL, resolveUrl) {

  function callbackAsync(callback, error, result) {
    setImmediate(function() { callback(error, result) })
  }

  function parseMapToJSON(string, data) {
    try {
      return JSON.parse(string.replace(/^\)\]\}'/, ""))
    } catch (error) {
      error.sourceMapData = data
      throw error
    }
  }

  function readSync(read, url, data) {
    var readUrl = url
    try {
      return String(read(readUrl))
    } catch (error) {
      error.sourceMapData = data
      throw error
    }
  }



  function resolveSourceMap(code, codeUrl, read, callback) {
    var mapData
    try {
      mapData = resolveSourceMapHelper(code, codeUrl)
    } catch (error) {
      return callbackAsync(callback, error)
    }
    if (!mapData || mapData.map) {
      return callbackAsync(callback, null, mapData)
    }
    var readUrl = mapData.url
    read(readUrl, function(error, result) {
      if (error) {
        error.sourceMapData = mapData
        return callback(error)
      }
      mapData.map = String(result)
      try {
        mapData.map = parseMapToJSON(mapData.map, mapData)
      } catch (error) {
        return callback(error)
      }
      callback(null, mapData)
    })
  }

  function resolveSourceMapSync(code, codeUrl, read) {
    var mapData = resolveSourceMapHelper(code, codeUrl)
    if (!mapData || mapData.map) {
      return mapData
    }
    mapData.map = readSync(read, mapData.url, mapData)
    mapData.map = parseMapToJSON(mapData.map, mapData)
    return mapData
  }

  var dataUriRegex = /^data:([^,;]*)(;[^,;]*)*(?:,(.*))?$/
  var jsonMimeTypeRegex = /^(?:application|text)\/json$/

  function resolveSourceMapHelper(code, codeUrl) {
    var url = sourceMappingURL.getFrom(code)
    if (!url) {
      return null
    }

    var dataUri = url.match(dataUriRegex)
    if (dataUri) {
      var mimeType = dataUri[1]
      var lastParameter = dataUri[2] || ""
      var encoded = dataUri[3] || ""
      var data = {
        sourceMappingURL: url,
        url: null,
        sourcesRelativeTo: codeUrl,
        map: encoded
      }
      if (!jsonMimeTypeRegex.test(mimeType)) {
        var error = new Error("Unuseful data uri mime type: " + (mimeType || "text/plain"))
        error.sourceMapData = data
        throw error
      }
      data.map = parseMapToJSON(
        lastParameter === ";base64" ? atob(encoded) : decodeURIComponent(encoded),
        data
      )
      return data
    }

    var mapUrl = resolveUrl(codeUrl, url)
    return {
      sourceMappingURL: url,
      url: mapUrl,
      sourcesRelativeTo: mapUrl,
      map: null
    }
  }



  function resolveSources(map, mapUrl, read, options, callback) {
    if (typeof options === "function") {
      callback = options
      options = {}
    }
    var pending = map.sources ? map.sources.length : 0
    var result = {
      sourcesResolved: [],
      sourcesContent:  []
    }

    if (pending === 0) {
      callbackAsync(callback, null, result)
      return
    }

    var done = function() {
      pending--
      if (pending === 0) {
        callback(null, result)
      }
    }

    resolveSourcesHelper(map, mapUrl, options, function(fullUrl, sourceContent, index) {
      result.sourcesResolved[index] = fullUrl
      if (typeof sourceContent === "string") {
        result.sourcesContent[index] = sourceContent
        callbackAsync(done, null)
      } else {
        var readUrl = fullUrl
        read(readUrl, function(error, source) {
          result.sourcesContent[index] = error ? error : String(source)
          done()
        })
      }
    })
  }

  function resolveSourcesSync(map, mapUrl, read, options) {
    var result = {
      sourcesResolved: [],
      sourcesContent:  []
    }

    if (!map.sources || map.sources.length === 0) {
      return result
    }

    resolveSourcesHelper(map, mapUrl, options, function(fullUrl, sourceContent, index) {
      result.sourcesResolved[index] = fullUrl
      if (read !== null) {
        if (typeof sourceContent === "string") {
          result.sourcesContent[index] = sourceContent
        } else {
          var readUrl = fullUrl
          try {
            result.sourcesContent[index] = String(read(readUrl))
          } catch (error) {
            result.sourcesContent[index] = error
          }
        }
      }
    })

    return result
  }

  var endingSlash = /\/?$/

  function resolveSourcesHelper(map, mapUrl, options, fn) {
    options = options || {}
    var fullUrl
    var sourceContent
    var sourceRoot
    for (var index = 0, len = map.sources.length; index < len; index++) {
      sourceRoot = null
      if (typeof options.sourceRoot === "string") {
        sourceRoot = options.sourceRoot
      } else if (typeof map.sourceRoot === "string" && options.sourceRoot !== false) {
        sourceRoot = map.sourceRoot
      }
      // If the sourceRoot is the empty string, it is equivalent to not setting
      // the property at all.
      if (sourceRoot === null || sourceRoot === '') {
        fullUrl = resolveUrl(mapUrl, map.sources[index])
      } else {
        // Make sure that the sourceRoot ends with a slash, so that `/scripts/subdir` becomes
        // `/scripts/subdir/<source>`, not `/scripts/<source>`. Pointing to a file as source root
        // does not make sense.
        fullUrl = resolveUrl(mapUrl, sourceRoot.replace(endingSlash, "/"), map.sources[index])
      }
      sourceContent = (map.sourcesContent || [])[index]
      fn(fullUrl, sourceContent, index)
    }
  }



  function resolve(code, codeUrl, read, options, callback) {
    if (typeof options === "function") {
      callback = options
      options = {}
    }
    if (code === null) {
      var mapUrl = codeUrl
      var data = {
        sourceMappingURL: null,
        url: mapUrl,
        sourcesRelativeTo: mapUrl,
        map: null
      }
      var readUrl = mapUrl
      read(readUrl, function(error, result) {
        if (error) {
          error.sourceMapData = data
          return callback(error)
        }
        data.map = String(result)
        try {
          data.map = parseMapToJSON(data.map, data)
        } catch (error) {
          return callback(error)
        }
        _resolveSources(data)
      })
    } else {
      resolveSourceMap(code, codeUrl, read, function(error, mapData) {
        if (error) {
          return callback(error)
        }
        if (!mapData) {
          return callback(null, null)
        }
        _resolveSources(mapData)
      })
    }

    function _resolveSources(mapData) {
      resolveSources(mapData.map, mapData.sourcesRelativeTo, read, options, function(error, result) {
        if (error) {
          return callback(error)
        }
        mapData.sourcesResolved = result.sourcesResolved
        mapData.sourcesContent  = result.sourcesContent
        callback(null, mapData)
      })
    }
  }

  function resolveSync(code, codeUrl, read, options) {
    var mapData
    if (code === null) {
      var mapUrl = codeUrl
      mapData = {
        sourceMappingURL: null,
        url: mapUrl,
        sourcesRelativeTo: mapUrl,
        map: null
      }
      mapData.map = readSync(read, mapUrl, mapData)
      mapData.map = parseMapToJSON(mapData.map, mapData)
    } else {
      mapData = resolveSourceMapSync(code, codeUrl, read)
      if (!mapData) {
        return null
      }
    }
    var result = resolveSourcesSync(mapData.map, mapData.sourcesRelativeTo, read, options)
    mapData.sourcesResolved = result.sourcesResolved
    mapData.sourcesContent  = result.sourcesContent
    return mapData
  }



  return {
    resolveSourceMap:     resolveSourceMap,
    resolveSourceMapSync: resolveSourceMapSync,
    resolveSources:       resolveSources,
    resolveSourcesSync:   resolveSourcesSync,
    resolve:              resolve,
    resolveSync:          resolveSync,
    parseMapToJSON:       parseMapToJSON
  }

}));