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