fediversity.eu/node_modules/sucrase/dist/computeSourceMap.js

"use strict";Object.defineProperty(exports, "__esModule", {value: true});var _genmapping = require('@jridgewell/gen-mapping');



var _charcodes = require('./parser/util/charcodes');












/**
 * Generate a source map indicating that each line maps directly to the original line,
 * with the tokens in their new positions.
 */
 function computeSourceMap(
  {code: generatedCode, mappings: rawMappings},
  filePath,
  options,
  source,
  tokens,
) {
  const sourceColumns = computeSourceColumns(source, tokens);
  const map = new (0, _genmapping.GenMapping)({file: options.compiledFilename});
  let tokenIndex = 0;
  // currentMapping is the output source index for the current input token being
  // considered.
  let currentMapping = rawMappings[0];
  while (currentMapping === undefined && tokenIndex < rawMappings.length - 1) {
    tokenIndex++;
    currentMapping = rawMappings[tokenIndex];
  }
  let line = 0;
  let lineStart = 0;
  if (currentMapping !== lineStart) {
    _genmapping.maybeAddSegment.call(void 0, map, line, 0, filePath, line, 0);
  }
  for (let i = 0; i < generatedCode.length; i++) {
    if (i === currentMapping) {
      const genColumn = currentMapping - lineStart;
      const sourceColumn = sourceColumns[tokenIndex];
      _genmapping.maybeAddSegment.call(void 0, map, line, genColumn, filePath, line, sourceColumn);
      while (
        (currentMapping === i || currentMapping === undefined) &&
        tokenIndex < rawMappings.length - 1
      ) {
        tokenIndex++;
        currentMapping = rawMappings[tokenIndex];
      }
    }
    if (generatedCode.charCodeAt(i) === _charcodes.charCodes.lineFeed) {
      line++;
      lineStart = i + 1;
      if (currentMapping !== lineStart) {
        _genmapping.maybeAddSegment.call(void 0, map, line, 0, filePath, line, 0);
      }
    }
  }
  const {sourceRoot, sourcesContent, ...sourceMap} = _genmapping.toEncodedMap.call(void 0, map);
  return sourceMap ;
} exports.default = computeSourceMap;

/**
 * Create an array mapping each token index to the 0-based column of the start
 * position of the token.
 */
function computeSourceColumns(code, tokens) {
  const sourceColumns = new Array(tokens.length);
  let tokenIndex = 0;
  let currentMapping = tokens[tokenIndex].start;
  let lineStart = 0;
  for (let i = 0; i < code.length; i++) {
    if (i === currentMapping) {
      sourceColumns[tokenIndex] = currentMapping - lineStart;
      tokenIndex++;
      currentMapping = tokens[tokenIndex].start;
    }
    if (code.charCodeAt(i) === _charcodes.charCodes.lineFeed) {
      lineStart = i + 1;
    }
  }
  return sourceColumns;
}