1#!/usr/bin/env node
2/**
3 * Copyright (c) Meta Platforms, Inc. and affiliates.
4 *
5 * This source code is licensed under the MIT license found in the
6 * LICENSE file in the root directory of this source tree.
7 *
8 * @format
9 */
10
11'use strict';
12
13const {composeSourceMaps} = require('metro-source-map');
14const fs = require('fs');
15
16const argv = process.argv.slice(2);
17let outputPath;
18for (let i = 0; i < argv.length; ) {
19  if (argv[i] === '-o') {
20    outputPath = argv[i + 1];
21    argv.splice(i, 2);
22    continue;
23  }
24  ++i;
25}
26if (!argv.length) {
27  process.stderr.write(
28    'Usage: node compose-source-maps.js <packager_sourcemap> <compiler_sourcemap> [-o output_file]\n',
29  );
30  process.exitCode = -1;
31} else {
32  const [packagerSourcemapPath, compilerSourcemapPath] = argv.splice(0, 2);
33  const packagerSourcemap = JSON.parse(
34    fs.readFileSync(packagerSourcemapPath, 'utf8'),
35  );
36  const compilerSourcemap = JSON.parse(
37    fs.readFileSync(compilerSourcemapPath, 'utf8'),
38  );
39
40  if (
41    packagerSourcemap.x_facebook_offsets != null ||
42    compilerSourcemap.x_facebook_offsets != null
43  ) {
44    throw new Error(
45      'Random Access Bundle (RAM) format is not supported by this tool; ' +
46        'it cannot process the `x_facebook_offsets` field provided ' +
47        'in the base and/or target source map(s)',
48    );
49  }
50
51  if (compilerSourcemap.x_facebook_segments != null) {
52    throw new Error(
53      'This tool cannot process the `x_facebook_segments` field provided ' +
54        'in the target source map.',
55    );
56  }
57
58  const composedMapJSON = JSON.stringify(
59    composeSourceMaps([packagerSourcemap, compilerSourcemap]),
60  );
61  if (outputPath) {
62    fs.writeFileSync(outputPath, composedMapJSON, 'utf8');
63  } else {
64    process.stdout.write();
65  }
66}
67