parcel-bundler/lib/utils/loadSourceMap.js

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

var _asyncToGenerator2 = _interopRequireDefault(require("@babel/runtime/helpers/asyncToGenerator"));

const logger = require('@parcel/logger');

const path = require('path');

const fs = require('@parcel/fs');

const SOURCEMAP_RE = /(?:\/\*|\/\/)\s*[@#]\s*sourceMappingURL\s*=\s*([^\s*]+)(?:\s*\*\/)?/;
const DATA_URL_RE = /^data:[^;]+(?:;charset=[^;]+)?;base64,(.*)/;

function loadSourceMap(_x) {
  return _loadSourceMap.apply(this, arguments);
}

function _loadSourceMap() {
  _loadSourceMap = (0, _asyncToGenerator2.default)(function* (asset) {
    // Get original sourcemap if there is any
    let match = asset.contents.match(SOURCEMAP_RE);
    let sourceMap;

    if (match) {
      asset.contents = asset.contents.replace(SOURCEMAP_RE, '');
      let url = match[1];
      let dataURLMatch = url.match(DATA_URL_RE);

      try {
        let json, filename;

        if (dataURLMatch) {
          filename = asset.name;
          json = Buffer.from(dataURLMatch[1], 'base64').toString();
        } else {
          filename = path.join(path.dirname(asset.name), url);
          json = yield fs.readFile(filename, 'utf8'); // Add as a dep so we watch the source map for changes.

          asset.addDependency(filename, {
            includedInParent: true
          });
        }

        sourceMap = JSON.parse(json); // Attempt to read missing source contents

        if (!sourceMap.sourcesContent) {
          sourceMap.sourcesContent = [];
        }

        let missingSources = sourceMap.sources.slice(sourceMap.sourcesContent.length);

        if (missingSources.length) {
          let contents = yield Promise.all(missingSources.map(
          /*#__PURE__*/
          function () {
            var _ref = (0, _asyncToGenerator2.default)(function* (source) {
              try {
                let sourceFile = path.join(path.dirname(filename), sourceMap.sourceRoot || '', source);
                let result = yield fs.readFile(sourceFile, 'utf8');
                asset.addDependency(sourceFile, {
                  includedInParent: true
                });
                return result;
              } catch (err) {
                logger.warn(`Could not load source file "${source}" in source map of "${asset.relativeName}".`);
              }
            });

            return function (_x2) {
              return _ref.apply(this, arguments);
            };
          }()));
          sourceMap.sourcesContent = sourceMap.sourcesContent.concat(contents);
        }
      } catch (e) {
        logger.warn(`Could not load existing sourcemap of "${asset.relativeName}".`);
        sourceMap = undefined;
      }
    }

    return sourceMap;
  });
  return _loadSourceMap.apply(this, arguments);
}

module.exports = loadSourceMap;