parcel-bundler/lib/SourceMap.js

Blazing fast, zero configuration web application bundler

"use strict";

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

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

const _require = require('source-map'),
      SourceMapConsumer = _require.SourceMapConsumer,
      SourceMapGenerator = _require.SourceMapGenerator;

const lineCounter = require('./utils/lineCounter');

class SourceMap {
  constructor(mappings, sources) {
    this.mappings = this.purifyMappings(mappings);
    this.sources = sources || {};
    this.lineCount = null;
  }

  purifyMappings(mappings) {
    if (Array.isArray(mappings)) {
      return mappings.filter(mapping => mapping && typeof mapping.original === 'object' && (mapping.original === null || typeof mapping.original.line === 'number' && mapping.original.line > 0 && typeof mapping.original.column === 'number' && mapping.source) && mapping.generated && typeof mapping.generated.line === 'number' && mapping.generated.line > 0 && typeof mapping.generated.column === 'number');
    }

    return [];
  }

  getConsumer(map) {
    return (0, _asyncToGenerator2.default)(function* () {
      if (map instanceof SourceMapConsumer) {
        return map;
      }

      map = typeof map === 'string' ? JSON.parse(map) : map;
      if (map.sourceRoot) delete map.sourceRoot;
      return new SourceMapConsumer(map);
    })();
  }

  addMap(map, lineOffset = 0, columnOffset = 0) {
    var _this = this;

    return (0, _asyncToGenerator2.default)(function* () {
      if (typeof map === 'string' || typeof map === 'object' && map.version) {
        let consumer = yield _this.getConsumer(map);
        if (!consumer) return _this;
        consumer.eachMapping(mapping => {
          _this.addConsumerMapping(mapping, lineOffset, columnOffset);

          if (!_this.sources[mapping.source]) {
            _this.sources[mapping.source] = consumer.sourceContentFor(mapping.source, true);
          }
        });

        if (consumer.destroy) {
          // Only needs to happen in source-map 0.7
          consumer.destroy();
        }
      } else if (map.mappings && map.sources) {
        if (!map.eachMapping) {
          map = new SourceMap(map.mappings, map.sources);
        }

        if (lineOffset === 0 && columnOffset === 0) {
          _this.mappings = _this.mappings.concat(map.mappings);
        } else {
          map.eachMapping(mapping => {
            _this.addMapping(mapping, lineOffset, columnOffset);
          });
        }

        Object.keys(map.sources).forEach(sourceName => {
          if (!_this.sources[sourceName]) {
            _this.sources[sourceName] = map.sources[sourceName];
          }
        });
      }

      return _this;
    })();
  }

  addMapping(mapping, lineOffset = 0, columnOffset = 0) {
    this.mappings.push({
      source: mapping.source,
      name: mapping.name,
      original: mapping.original,
      generated: {
        line: mapping.generated.line + lineOffset,
        column: mapping.generated.column + columnOffset
      }
    });
  }

  addConsumerMapping(mapping, lineOffset = 0, columnOffset = 0) {
    let original = null;

    if (typeof mapping.originalLine === 'number' && mapping.originalLine > 0 && typeof mapping.originalColumn === 'number') {
      original = {
        line: mapping.originalLine,
        column: mapping.originalColumn
      };
    }

    this.mappings.push({
      source: original ? mapping.source : null,
      name: mapping.name,
      original,
      generated: {
        line: mapping.generatedLine + lineOffset,
        column: mapping.generatedColumn + columnOffset
      }
    });
  }

  eachMapping(callback) {
    this.mappings.forEach(callback);
  }

  generateEmptyMap(sourceName, sourceContent) {
    this.sources[sourceName] = sourceContent;
    this.lineCount = lineCounter(sourceContent);

    for (let line = 1; line < this.lineCount + 1; line++) {
      this.addMapping({
        source: sourceName,
        original: {
          line: line,
          column: 0
        },
        generated: {
          line: line,
          column: 0
        }
      });
    }

    return this;
  }

  extendSourceMap(original, extension) {
    var _this2 = this;

    return (0, _asyncToGenerator2.default)(function* () {
      if (!(extension instanceof SourceMap)) {
        extension = yield new SourceMap().addMap(extension);
      }

      if (!(original instanceof SourceMap)) {
        original = yield _this2.getConsumer(original);
      }

      extension.eachMapping(mapping => {
        let originalMapping = original.originalPositionFor({
          line: mapping.original.line,
          column: mapping.original.column
        });

        if (!originalMapping || !originalMapping.line) {
          return;
        }

        _this2.addMapping({
          source: originalMapping.source,
          name: originalMapping.name,
          original: {
            line: originalMapping.line,
            column: originalMapping.column
          },
          generated: {
            line: mapping.generated.line,
            column: mapping.generated.column
          }
        });

        if (!_this2.sources[originalMapping.source]) {
          _this2.sources[originalMapping.source] = original.sourceContentFor(originalMapping.source, true);
        }
      });

      if (original.destroy) {
        // Only needs to happen in source-map 0.7
        original.destroy();
      }

      return _this2;
    })();
  }

  findClosestGenerated(line, column) {
    if (line < 1) {
      throw new Error('Line numbers must be >= 1');
    }

    if (column < 0) {
      throw new Error('Column numbers must be >= 0');
    }

    if (this.mappings.length < 1) {
      return undefined;
    }

    let startIndex = 0;
    let stopIndex = this.mappings.length - 1;
    let middleIndex = stopIndex + startIndex >>> 1;

    while (startIndex < stopIndex && this.mappings[middleIndex].generated.line !== line) {
      let mid = this.mappings[middleIndex].generated.line;

      if (line < mid) {
        stopIndex = middleIndex - 1;
      } else if (line > mid) {
        startIndex = middleIndex + 1;
      }

      middleIndex = stopIndex + startIndex >>> 1;
    }

    let mapping = this.mappings[middleIndex];

    if (!mapping || mapping.generated.line !== line) {
      return this.mappings.length - 1;
    }

    while (middleIndex >= 1 && this.mappings[middleIndex - 1].generated.line === line) {
      middleIndex--;
    }

    while (middleIndex < this.mappings.length - 1 && this.mappings[middleIndex + 1].generated.line === line && column > this.mappings[middleIndex].generated.column) {
      middleIndex++;
    }

    return middleIndex;
  }

  findClosest(line, column, key) {
    if (line < 1) {
      throw new Error('Line numbers must be >= 1');
    }

    if (column < 0) {
      throw new Error('Column numbers must be >= 0');
    }

    if (this.mappings.length < 1) {
      return undefined;
    }

    let startIndex = 0;
    let stopIndex = this.mappings.length - 1;
    let middleIndex = Math.floor((stopIndex + startIndex) / 2);

    while (startIndex < stopIndex && this.mappings[middleIndex][key].line !== line) {
      if (line < this.mappings[middleIndex][key].line) {
        stopIndex = middleIndex - 1;
      } else if (line > this.mappings[middleIndex][key].line) {
        startIndex = middleIndex + 1;
      }

      middleIndex = Math.floor((stopIndex + startIndex) / 2);
    }

    var mapping = this.mappings[middleIndex];

    if (!mapping || mapping[key].line !== line) {
      return this.mappings.length - 1;
    }

    while (middleIndex >= 1 && this.mappings[middleIndex - 1][key].line === line) {
      middleIndex--;
    }

    while (middleIndex < this.mappings.length - 1 && this.mappings[middleIndex + 1][key].line === line && column > this.mappings[middleIndex][key].column) {
      middleIndex++;
    }

    return middleIndex;
  }

  originalPositionFor(generatedPosition) {
    let index = this.findClosestGenerated(generatedPosition.line, generatedPosition.column);
    let mapping = this.mappings[index];

    if (!mapping || !mapping.original) {
      return null;
    }

    return {
      source: mapping.source,
      name: mapping.name,
      line: mapping.original.line,
      column: mapping.original.column
    };
  }

  generatedPositionFor(originalPosition) {
    let index = this.findClosest(originalPosition.line, originalPosition.column, 'original');
    let mapping = this.mappings[index];
    return {
      source: mapping.source,
      name: mapping.name,
      line: mapping.generated.line,
      column: mapping.generated.column
    };
  }

  sourceContentFor(fileName) {
    return this.sources[fileName];
  }

  offset(lineOffset = 0, columnOffset = 0) {
    this.mappings.map(mapping => {
      mapping.generated.line = mapping.generated.line + lineOffset;
      mapping.generated.column = mapping.generated.column + columnOffset;
      return mapping;
    });

    if (this.lineCount != null) {
      this.lineCount += lineOffset;
    }
  }

  stringify(file, sourceRoot) {
    let generator = new SourceMapGenerator({
      file,
      sourceRoot
    });
    this.eachMapping(mapping => generator.addMapping(mapping));
    Object.keys(this.sources).forEach(sourceName => generator.setSourceContent(sourceName, this.sources[sourceName]));
    return generator.toString();
  }

}

module.exports = SourceMap;