convert-source-map 2.0.0

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify pkg:npm/convert-source-map@2.0.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/convert-source-map@2.0.0
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@10.9.8
  - runtime: node@22.23.2

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:ea77ca5ba5a7f7298fe4423f887787d9b1d65aa5a5dbe0bb6661db739e3d06e2","constraints":{"executionContext":"node"},"contract":["fromObject converts a source map object and returns new copy via toObject and JSON string via toJSON","fromJSON parses a source map JSON string and allows modifying properties via getProperty, setProperty, and addProperty","fromBase64 and toBase64 convert between base64-encoded strings and source map objects","fromComment and toComment parse and format inline base64 and URI-encoded sourceMappingURL comments","fromSource finds the last inline source map comment from source code or returns null if absent","removeComments and removeMapFileComments strip inline data URIs and external map file comments from source text","generateMapFileComment formats single-line and multi-line sourceMappingURL references to map files","fromMapFileComment reads map file content using a custom reader function"],"goal":"verify pkg:npm/convert-source-map@2.0.0","kind":"HOW","packages":["pkg:npm/convert-source-map@2.0.0"],"schemaVersion":1},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"cjs","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/convert-source-map@2.0.0"],"schemaVersion":1,"subject":"pkg:npm/convert-source-map@2.0.0","verifierAdapter":"node-typescript@1"}

{
  "name": "sample-convert-source-map",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-convert-source-map",
      "version": "1.0.0",
      "dependencies": {
        "convert-source-map": "2.0.0"
      }
    },
    "node_modules/convert-source-map": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/convert-source-map/-/convert-source-map-2.0.0.tgz",
      "integrity": "sha512-Kvp459HrV2FEJ1CAsi1Ku+MY3kasH19TFykTz2xWmMeq6bk2NU3XXvfJ+Q61m0xktWwt+1HSYf3JZsTms3aRJg==",
      "license": "MIT"
    }
  }
}

{
  "name": "sample-convert-source-map",
  "version": "1.0.0",
  "private": true,
  "dependencies": {
    "convert-source-map": "2.0.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/convert-source-map@2.0.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/convert-source-map@2.0.0"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

import assert from 'node:assert/strict';
import convert from 'convert-source-map';

const rawMap = {
  version: 3,
  file: 'min.js',
  names: ['bar', 'baz'],
  sources: ['one.js', 'two.js'],
  sourceRoot: 'http://example.com/www/js/',
  mappings: 'CAAC,IAAI,IAAM,SAAUA,GAClB,OAAOC,OAAU,GACrB',
};

// 1. fromObject converts a source map object and returns new copy via toObject and JSON string via toJSON
{
  const conv = convert.fromObject(rawMap);
  const obj = conv.toObject();
  assert.deepEqual(obj, rawMap);
  assert.notEqual(obj, rawMap);

  const jsonStr = conv.toJSON();
  assert.equal(typeof jsonStr, 'string');
  assert.deepEqual(JSON.parse(jsonStr), rawMap);
}

// 2. fromJSON parses a source map JSON string and allows modifying properties via getProperty, setProperty, and addProperty
{
  const json = JSON.stringify(rawMap);
  const conv = convert.fromJSON(json);
  assert.equal(conv.getProperty('file'), 'min.js');

  conv.setProperty('file', 'bundle.min.js');
  assert.equal(conv.getProperty('file'), 'bundle.min.js');

  conv.addProperty('x_custom', 'custom-value');
  assert.equal(conv.getProperty('x_custom'), 'custom-value');

  assert.throws(
    () => {
      conv.addProperty('file', 'other.js');
    },
    {
      name: 'Error',
      message: 'property "file" already exists on the sourcemap, use set property instead',
    }
  );
}

// 3. fromBase64 and toBase64 convert between base64-encoded strings and source map objects
{
  const conv = convert.fromObject(rawMap);
  const base64 = conv.toBase64();
  assert.equal(typeof base64, 'string');

  const parsed = convert.fromBase64(base64);
  assert.deepEqual(parsed.toObject(), rawMap);
}

// 4. fromComment and toComment parse and format inline base64 and URI-encoded sourceMappingURL comments
{
  const conv = convert.fromObject(rawMap);

  const singleLineComment = conv.toComment();
  assert.ok(singleLineComment.startsWith('//# sourceMappingURL=data:application/json;charset=utf-8;base64,'));
  const parsedFromSingle = convert.fromComment(singleLineComment);
  assert.deepEqual(parsedFromSingle.toObject(), rawMap);

  const multiLineComment = conv.toComment({ multiline: true });
  assert.ok(multiLineComment.startsWith('/*# sourceMappingURL=data:application/json;charset=utf-8;base64,'));
  assert.ok(multiLineComment.endsWith(' */'));
  const parsedFromMulti = convert.fromComment(multiLineComment);
  assert.deepEqual(parsedFromMulti.toObject(), rawMap);

  const uriComment = conv.toComment({ encoding: 'uri' });
  assert.ok(uriComment.startsWith('//# sourceMappingURL=data:application/json;charset=utf-8,'));
  const parsedFromUri = convert.fromComment(uriComment);
  assert.deepEqual(parsedFromUri.toObject(), rawMap);
}

// 5. fromSource finds the last inline source map comment from source code or returns null if absent
{
  const conv = convert.fromObject(rawMap);
  const comment = conv.toComment();
  const sourceCode = `function foo() { return 42; }\n${comment}`;

  const extracted = convert.fromSource(sourceCode);
  assert.ok(extracted);
  assert.deepEqual(extracted.toObject(), rawMap);

  const noCommentCode = 'function bar() { return 1; }';
  assert.equal(convert.fromSource(noCommentCode), null);
}

// 6. removeComments and removeMapFileComments strip inline data URIs and external map file comments from source text
{
  const inlineComment = convert.fromObject(rawMap).toComment();
  const codeWithInline = `console.log("hello");\n${inlineComment}\n`;
  const codeWithoutInline = convert.removeComments(codeWithInline);
  assert.equal(codeWithoutInline.trim(), 'console.log("hello");');

  const mapFileComment = convert.generateMapFileComment('bundle.js.map');
  const codeWithMapFile = `console.log("world");\n${mapFileComment}\n`;
  const codeWithoutMapFile = convert.removeMapFileComments(codeWithMapFile);
  assert.equal(codeWithoutMapFile.trim(), 'console.log("world");');
}

// 7. generateMapFileComment formats single-line and multi-line sourceMappingURL references to map files
{
  const single = convert.generateMapFileComment('app.min.js.map');
  assert.equal(single, '//# sourceMappingURL=app.min.js.map');

  const multi = convert.generateMapFileComment('app.min.js.map', { multiline: true });
  assert.equal(multi, '/*# sourceMappingURL=app.min.js.map */');
}

// 8. fromMapFileComment reads map file content using a custom reader function
{
  const comment = '//# sourceMappingURL=mapfile.json';
  const readFn = (filename) => {
    assert.equal(filename, 'mapfile.json');
    return JSON.stringify(rawMap);
  };

  const conv = convert.fromMapFileComment(comment, readFn);
  assert.deepEqual(conv.toObject(), rawMap);
}