msd-core/tests/settings-jsonc.test.cjs

// allow-test-rule: structural-regression-guard
// Reads hook .js or bin/install.js source to assert structural invariants
// (search array order, function wiring, path constants) that cannot be
// verified by observing runtime outputs alone. Per CONTRIBUTING.md exception matrix.

/**
 * GSD Tools Tests - settings.json JSONC (JSON with comments) support
 *
 * Validates that the installer's readSettings() correctly handles
 * settings.json files containing comments (line and block) without
 * silently overwriting them with empty objects.
 *
 * Closes: #1461
 */

const { test, describe } = require('node:test');
const assert = require('node:assert/strict');
const fs = require('fs');
const os = require('os');
const path = require('path');

// ─── load real install.js exports once ───────────────────────────────────────
//
// install.js prints a banner at module-load time (outside its GSD_TEST_MODE
// guard) — silence stdout for the duration of the require() so test output
// stays clean.  The main-logic block IS gated on GSD_TEST_MODE, so no
// installer side-effects run.
//
// Guard line (bin/install.js:12287):
//   if (require.main === module && !process.env.GSD_TEST_MODE) {
//
let installExports;
{
  process.env.GSD_TEST_MODE = '1';
  const _origWrite = process.stdout.write.bind(process.stdout);
  process.stdout.write = () => true; // suppress banner
  try {
    installExports = require('../bin/install.js');
  } finally {
    process.stdout.write = _origWrite;
  }
}
const { readSettings, stripJsonComments } = installExports;

// ─── tests ───────────────────────────────────────────────────────────────────

describe('stripJsonComments (#1461)', () => {

  test('strips line comments', () => {
    const input = `{
  // This is a comment
  "key": "value"
}`;
    const result = JSON.parse(stripJsonComments(input));
    assert.deepStrictEqual(result, { key: 'value' });
  });

  test('strips block comments', () => {
    const input = `{
  /* Block comment */
  "key": "value"
}`;
    const result = JSON.parse(stripJsonComments(input));
    assert.deepStrictEqual(result, { key: 'value' });
  });

  test('strips multi-line block comments', () => {
    const input = `{
  /*
   * Multi-line
   * block comment
   */
  "key": "value"
}`;
    const result = JSON.parse(stripJsonComments(input));
    assert.deepStrictEqual(result, { key: 'value' });
  });

  test('preserves comments inside string values', () => {
    const input = `{
  "url": "https://example.com/path",
  "description": "Use // for line comments"
}`;
    const result = JSON.parse(stripJsonComments(input));
    assert.strictEqual(result.url, 'https://example.com/path');
    assert.strictEqual(result.description, 'Use // for line comments');
  });

  test('handles trailing commas', () => {
    const input = `{
  "a": 1,
  "b": 2,
}`;
    const result = JSON.parse(stripJsonComments(input));
    assert.deepStrictEqual(result, { a: 1, b: 2 });
  });

  test('handles inline comments after values', () => {
    const input = `{
  "timeout": 5000, // milliseconds
  "retries": 3 // max attempts
}`;
    const result = JSON.parse(stripJsonComments(input));
    assert.strictEqual(result.timeout, 5000);
    assert.strictEqual(result.retries, 3);
  });

  test('handles standard JSON (no comments) unchanged', () => {
    const input = '{"key": "value", "num": 42}';
    const result = JSON.parse(stripJsonComments(input));
    assert.deepStrictEqual(result, { key: 'value', num: 42 });
  });

  test('handles empty object', () => {
    const result = JSON.parse(stripJsonComments('{}'));
    assert.deepStrictEqual(result, {});
  });

  test('handles real-world settings.json with comments', () => {
    const input = `{
  // My configuration
  "hooks": {
    "SessionStart": [
      {
        "matcher": "", /* match all */
        "hooks": [
          {
            "type": "command",
            "command": "node ~/.claude/hooks/gsd-statusline.js"
          }
        ]
      }
    ]
  },
  "statusLine": {
    "command": "node ~/.claude/hooks/gsd-statusline.js",
    "refreshInterval": 10
  }
}`;
    const result = JSON.parse(stripJsonComments(input));
    assert.ok(result.hooks, 'should have hooks');
    assert.ok(result.statusLine, 'should have statusLine');
    assert.strictEqual(result.statusLine.refreshInterval, 10);
  });
});

describe('readSettings null return on malformed files (#1461)', () => {
  test('install.js contains JSONC stripping in readSettings', () => {
    const installPath = path.join(__dirname, '..', 'bin', 'install.js');
    const content = fs.readFileSync(installPath, 'utf8');
    assert.ok(content.includes('stripJsonComments'),
      'install.js should use stripJsonComments in readSettings');
  });

  test('readSettings returns null on truly malformed files (not empty object)', () => {
    const installPath = path.join(__dirname, '..', 'bin', 'install.js');
    const content = fs.readFileSync(installPath, 'utf8');
    assert.ok(content.includes('return null'),
      'readSettings should return null on parse failure, not empty object');
  });

  test('callers guard against null readSettings return', () => {
    const installPath = path.join(__dirname, '..', 'bin', 'install.js');
    const content = fs.readFileSync(installPath, 'utf8');
    // Should have null guards at the settings configuration call sites
    assert.ok(
      content.includes('=== null') || content.includes('rawSettings === null'),
      'callers should check for null return from readSettings'
    );
  });
});

// ─── seam-4 (#1191): real readSettings via exported function ─────────────────
//
// These tests exercise the REAL readSettings from bin/install.js (not a
// replica), using real temp files.  The structural grep below is a secondary
// belt-and-suspenders anchoring the source text; the primary assertions are
// the behavioural ones beneath it.

describe('readSettings: JSON null coalesced to empty, malformed warns (#1191)', () => {
  test('source contains the null-coalescing guard (parsed === null ? {})', () => {
    // Structural anchor: if someone removes the coalescing, this test catches it
    // before the behavioural test below even runs.
    const installPath = path.join(__dirname, '..', 'bin', 'install.js');
    const content = fs.readFileSync(installPath, 'utf8');
    assert.ok(
      content.includes('parsed === null ? {}'),
      'install.js readSettings must coalesce valid JSON null to {} (not malformed warning)'
    );
  });

  test('valid JSON null content returns empty object with no malformed warning (real function)', () => {
    // A settings file containing literally `null` is valid JSON.
    // readSettings must treat it as empty settings ({}) — no warning emitted.
    const tmpFile = path.join(os.tmpdir(), `gsd-settings-test-null-${process.pid}.json`);
    fs.writeFileSync(tmpFile, 'null');
    const warnCalls = [];
    const origWarn = console.warn;
    console.warn = (...args) => warnCalls.push(args.join(' '));
    let result;
    try {
      result = readSettings(tmpFile);
    } finally {
      console.warn = origWarn;
      fs.unlinkSync(tmpFile);
    }
    assert.deepStrictEqual(result, {}, 'JSON null must coalesce to {}');
    const malformedWarns = warnCalls.filter(w => w.includes('malformed') || w.includes('Could not parse'));
    assert.strictEqual(malformedWarns.length, 0, 'no malformed warning expected for valid JSON null');
  });

  test('malformed content returns null and emits malformed warning (real function)', () => {
    // A file containing `{ broken` is not valid JSON (even after comment-stripping).
    // readSettings must emit a malformed warning and return null.
    const tmpFile = path.join(os.tmpdir(), `gsd-settings-test-broken-${process.pid}.json`);
    fs.writeFileSync(tmpFile, '{ broken');
    const warnCalls = [];
    const origWarn = console.warn;
    console.warn = (...args) => warnCalls.push(args.join(' '));
    let result;
    try {
      result = readSettings(tmpFile);
    } finally {
      console.warn = origWarn;
      fs.unlinkSync(tmpFile);
    }
    assert.strictEqual(result, null, 'malformed JSON must return null');
    const malformedWarns = warnCalls.filter(w => w.includes('malformed') || w.includes('Could not parse'));
    assert.strictEqual(malformedWarns.length, 1, 'exactly one malformed warning expected');
  });

  test('valid object content returns parsed object with no warning (real function)', () => {
    const tmpFile = path.join(os.tmpdir(), `gsd-settings-test-valid-${process.pid}.json`);
    fs.writeFileSync(tmpFile, '{"hooks":{}}');
    const warnCalls = [];
    const origWarn = console.warn;
    console.warn = (...args) => warnCalls.push(args.join(' '));
    let result;
    try {
      result = readSettings(tmpFile);
    } finally {
      console.warn = origWarn;
      fs.unlinkSync(tmpFile);
    }
    assert.deepStrictEqual(result, { hooks: {} }, 'valid object must be returned as-is');
    const malformedWarns = warnCalls.filter(w => w.includes('malformed') || w.includes('Could not parse'));
    assert.strictEqual(malformedWarns.length, 0, 'no warning expected for valid JSON object');
  });

  test('absent file returns empty object with no warning (real function)', () => {
    const tmpFile = path.join(os.tmpdir(), `gsd-settings-test-absent-${process.pid}.json`);
    // ensure file does NOT exist
    try { fs.unlinkSync(tmpFile); } catch { /* already absent */ }
    const warnCalls = [];
    const origWarn = console.warn;
    console.warn = (...args) => warnCalls.push(args.join(' '));
    let result;
    try {
      result = readSettings(tmpFile);
    } finally {
      console.warn = origWarn;
    }
    assert.deepStrictEqual(result, {}, 'absent file must return {}');
    assert.strictEqual(warnCalls.length, 0, 'no warning expected for absent file');
  });
});