ktg-plugin-marketplace/plugins/ms-ai-architect/tests/kb-update/test-atomic-write.test.mjs
Kjell Tore Guttormsen 4a615b10ce feat(ms-ai-architect): add lib/atomic-write for crash-safe state files [skip-docs]
Foundation lib for status-fil + lock-fil writes in v1.12.0 cron rewrite.
Pattern: writeFileSync to <path>.tmp.<pid>.<random> then renameSync to
target. Defends against half-written files; readers either see the
previous version or the new one, never a partial.

- atomicWriteSync(path, content) — string or Buffer
- atomicWriteJson(path, obj) — 2-space indent, trailing newline
- Windows EEXIST/EPERM defensive fallback (unlink target + rename)
- Best-effort tmp cleanup on writeFileSync failure
- crypto.randomInt(0, 2**32) two-arg form (unambiguous across Node)

9/9 tests pass including 50-way concurrent-write fuzzer (async-aware
withTmp helper).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-05 10:32:13 +02:00

115 lines
3.7 KiB
JavaScript

// tests/kb-update/test-atomic-write.test.mjs
// Unit tests for scripts/kb-update/lib/atomic-write.mjs
import { test } from 'node:test';
import assert from 'node:assert/strict';
import { mkdtempSync, rmSync, readFileSync, existsSync, readdirSync, writeFileSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import { atomicWriteSync, atomicWriteJson } from '../../scripts/kb-update/lib/atomic-write.mjs';
async function withTmp(fn) {
const dir = mkdtempSync(join(tmpdir(), 'aw-test-'));
try {
return await fn(dir);
} finally {
rmSync(dir, { recursive: true, force: true });
}
}
test('atomicWriteSync — writes string content to target', () => {
withTmp((dir) => {
const path = join(dir, 'state.txt');
atomicWriteSync(path, 'hello');
assert.equal(readFileSync(path, 'utf8'), 'hello');
});
});
test('atomicWriteSync — leaves no .tmp orphan after success', () => {
withTmp((dir) => {
const path = join(dir, 'state.txt');
atomicWriteSync(path, 'ok');
const orphans = readdirSync(dir).filter((f) => f.includes('.tmp.'));
assert.deepEqual(orphans, []);
});
});
test('atomicWriteSync — overwrites existing file', () => {
withTmp((dir) => {
const path = join(dir, 'state.txt');
writeFileSync(path, 'old');
atomicWriteSync(path, 'new');
assert.equal(readFileSync(path, 'utf8'), 'new');
});
});
test('atomicWriteSync — accepts Buffer content', () => {
withTmp((dir) => {
const path = join(dir, 'bin');
atomicWriteSync(path, Buffer.from([0x01, 0x02, 0x03]));
const data = readFileSync(path);
assert.equal(data.length, 3);
assert.equal(data[0], 0x01);
});
});
test('atomicWriteJson — round-trips object', () => {
withTmp((dir) => {
const path = join(dir, 'state.json');
const obj = { schema_version: 1, status: 'success', items: [1, 2, 3] };
atomicWriteJson(path, obj);
const read = JSON.parse(readFileSync(path, 'utf8'));
assert.deepEqual(read, obj);
});
});
test('atomicWriteJson — pretty-prints with 2-space indent', () => {
withTmp((dir) => {
const path = join(dir, 'state.json');
atomicWriteJson(path, { a: 1, b: { c: 2 } });
const text = readFileSync(path, 'utf8');
assert.match(text, /\n {2}"a": 1/);
assert.match(text, /\n {4}"c": 2/);
});
});
test('atomicWriteJson — leaves no .tmp orphan', () => {
withTmp((dir) => {
const path = join(dir, 'state.json');
atomicWriteJson(path, { ok: true });
const orphans = readdirSync(dir).filter((f) => f.includes('.tmp.'));
assert.deepEqual(orphans, []);
});
});
test('atomicWriteSync — concurrent writes do not corrupt', async () => {
await withTmp(async (dir) => {
const path = join(dir, 'concurrent.json');
const writes = [];
for (let i = 0; i < 50; i++) {
writes.push(
Promise.resolve().then(() => atomicWriteJson(path, { iter: i, payload: 'x'.repeat(100) }))
);
}
await Promise.all(writes);
// Final read must be valid JSON, regardless of which write won.
const text = readFileSync(path, 'utf8');
const obj = JSON.parse(text);
assert.equal(typeof obj.iter, 'number');
assert.ok(obj.iter >= 0 && obj.iter < 50);
assert.equal(obj.payload.length, 100);
// No .tmp orphans
const orphans = readdirSync(dir).filter((f) => f.includes('.tmp.'));
assert.deepEqual(orphans, []);
});
});
test('atomicWriteSync — tmp filename uses pid + random suffix', () => {
// Indirect verification: write then immediately check the only file in dir is the target.
withTmp((dir) => {
const path = join(dir, 'target.json');
atomicWriteSync(path, '{}');
const files = readdirSync(dir);
assert.deepEqual(files, ['target.json']);
});
});