parcel-bundler/lib/Pipeline.js

'use strict';

function _asyncToGenerator(fn) { return function () { var gen = fn.apply(this, arguments); return new Promise(function (resolve, reject) { function step(key, arg) { try { var info = gen[key](arg); var value = info.value; } catch (error) { reject(error); return; } if (info.done) { resolve(value); } else { return Promise.resolve(value).then(function (value) { step("next", value); }, function (err) { step("throw", err); }); } } return step("next"); }); }; }

const Parser = require('./Parser');
const path = require('path');
const md5 = require('./utils/md5');

/**
 * A Pipeline composes multiple Asset types together.
 */
class Pipeline {
  constructor(options) {
    this.options = options;
    this.parser = new Parser(options);
  }

  process(path, pkg, options) {
    var _this = this;

    return _asyncToGenerator(function* () {
      let asset = _this.parser.getAsset(path, pkg, options);
      let generated = yield _this.processAsset(asset);
      let generatedMap = {};
      var _iteratorNormalCompletion = true;
      var _didIteratorError = false;
      var _iteratorError = undefined;

      try {
        for (var _iterator = generated[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
          let rendition = _step.value;

          generatedMap[rendition.type] = rendition.value;
        }
      } catch (err) {
        _didIteratorError = true;
        _iteratorError = err;
      } finally {
        try {
          if (!_iteratorNormalCompletion && _iterator.return) {
            _iterator.return();
          }
        } finally {
          if (_didIteratorError) {
            throw _iteratorError;
          }
        }
      }

      return {
        dependencies: Array.from(asset.dependencies.values()),
        generated: generatedMap,
        hash: asset.hash,
        cacheData: asset.cacheData
      };
    })();
  }

  processAsset(asset) {
    var _this2 = this;

    return _asyncToGenerator(function* () {
      try {
        yield asset.process();
      } catch (err) {
        throw asset.generateErrorMessage(err);
      }

      let inputType = path.extname(asset.name).slice(1);
      let generated = [];

      var _iteratorNormalCompletion2 = true;
      var _didIteratorError2 = false;
      var _iteratorError2 = undefined;

      try {
        for (var _iterator2 = _this2.iterateRenditions(asset)[Symbol.iterator](), _step2; !(_iteratorNormalCompletion2 = (_step2 = _iterator2.next()).done); _iteratorNormalCompletion2 = true) {
          let rendition = _step2.value;
          let type = rendition.type,
              value = rendition.value;

          if (typeof value !== 'string' || rendition.final) {
            generated.push(rendition);
            continue;
          }

          // Find an asset type for the rendition type.
          // If the asset is not already an instance of this asset type, process it.
          let AssetType = _this2.parser.findParser(asset.name.slice(0, -inputType.length) + type);
          if (!(asset instanceof AssetType)) {
            let opts = Object.assign({ rendition }, asset.options);
            let subAsset = new AssetType(asset.name, asset.package, opts);
            subAsset.contents = value;
            subAsset.dependencies = asset.dependencies;

            let processed = yield _this2.processAsset(subAsset);
            generated = generated.concat(processed);
            Object.assign(asset.cacheData, subAsset.cacheData);
            asset.hash = md5(asset.hash + subAsset.hash);
          } else {
            generated.push(rendition);
          }
        }

        // Post process. This allows assets a chance to modify the output produced by sub-asset types.
      } catch (err) {
        _didIteratorError2 = true;
        _iteratorError2 = err;
      } finally {
        try {
          if (!_iteratorNormalCompletion2 && _iterator2.return) {
            _iterator2.return();
          }
        } finally {
          if (_didIteratorError2) {
            throw _iteratorError2;
          }
        }
      }

      asset.generated = generated;
      try {
        generated = yield asset.postProcess(generated);
      } catch (err) {
        throw asset.generateErrorMessage(err);
      }

      return generated;
    })();
  }

  *iterateRenditions(asset) {
    if (Array.isArray(asset.generated)) {
      return yield* asset.generated;
    }

    if (typeof asset.generated === 'string') {
      return yield {
        type: asset.type,
        value: asset.generated
      };
    }

    // Backward compatibility support for the old API.
    // Assume all renditions are final - don't compose asset types together.
    for (let type in asset.generated) {
      yield {
        type,
        value: asset.generated[type],
        final: true
      };
    }
  }
}

module.exports = Pipeline;