Add test harness: setup lib, dev mode, automated test runner

test/test.mjs

@@ -0,0 +1,119 @@
+#!/usr/bin/env node
+// Automated test runner. Exit 0 = pass, exit 1 = fail.
+// Requires root (sudo) for mount and fa2json.
+
+import { createInterface } from 'node:readline';
+import { promises as fs } from 'node:fs';
+import { join } from 'node:path';
+import { setup, spawnFa2json } from './lib/setup.mjs';
+
+// Fanotify mask flags
+const FAN_ATTRIB      = 0x4;
+const FAN_CLOSE_WRITE = 0x8;
+const FAN_CREATE      = 0x100;
+const FAN_DELETE      = 0x200;
+const FAN_RENAME      = 0x10000000;
+const FAN_ONDIR       = 0x40000000;
+
+const { mnt, teardown } = await setup();
+const fa2json = spawnFa2json(mnt);
+
+// Event buffer and marker machinery
+const events = [];
+let markerResolve = null;
+let markerName = null;
+let markerCounter = 0;
+
+const rl = createInterface({ input: fa2json.stdout });
+rl.on('line', line => {
+	const event = JSON.parse(line);
+	// Strip mount prefix from all path fields
+	for (const key of ['name', 'old', 'new']) {
+		if (event[key]) event[key] = event[key].slice(mnt.length);
+	}
+	events.push(event);
+	if (markerResolve && event.name === `/.marker_${markerName}` && (event.mask & FAN_CREATE)) {
+		markerResolve();
+		markerResolve = null;
+	}
+});
+
+// Perform a FS operation, drop a marker, collect events up to that marker
+async function doOp(label, fn) {
+	const id = markerCounter++;
+	await fn();
+	await fs.writeFile(join(mnt, `.marker_${id}`), '');
+	await new Promise(resolve => {
+		markerName = id;
+		markerResolve = resolve;
+	});
+	// Collect all events since previous marker (excluding marker events themselves)
+	const batch = events.splice(0).filter(e => !e.name?.startsWith('/.marker_'));
+	return { label, batch };
+}
+
+function assert(label, batch, check) {
+	if (!check(batch)) {
+		console.error(`FAIL: ${label}`);
+		console.error('Batch:', JSON.stringify(batch, null, 2));
+		throw new Error(`Assertion failed: ${label}`);
+	}
+}
+
+function hasEvent(batch, flags, path, field = 'name') {
+	return batch.some(e => (e.mask & flags) === flags && e[field] === path);
+}
+
+try {
+	let op;
+
+	op = await doOp('mkdir /dir_a', () => fs.mkdir(join(mnt, 'dir_a')));
+	assert(op.label, op.batch, b => hasEvent(b, FAN_CREATE | FAN_ONDIR, '/dir_a'));
+
+	op = await doOp('touch /file_a.txt', () => fs.writeFile(join(mnt, 'file_a.txt'), ''));
+	assert(op.label, op.batch, b => hasEvent(b, FAN_CREATE, '/file_a.txt'));
+
+	op = await doOp('write /file_a.txt', () => fs.writeFile(join(mnt, 'file_a.txt'), 'content'));
+	assert(op.label, op.batch, b => hasEvent(b, FAN_CLOSE_WRITE, '/file_a.txt'));
+
+	op = await doOp('mkdir /dir_b', () => fs.mkdir(join(mnt, 'dir_b')));
+	assert(op.label, op.batch, b => hasEvent(b, FAN_CREATE | FAN_ONDIR, '/dir_b'));
+
+	op = await doOp('touch /dir_b/nested.txt', () => fs.writeFile(join(mnt, 'dir_b', 'nested.txt'), ''));
+	assert(op.label, op.batch, b => hasEvent(b, FAN_CREATE, '/dir_b/nested.txt'));
+
+	op = await doOp('mv /file_a.txt /file_b.txt', () => fs.rename(join(mnt, 'file_a.txt'), join(mnt, 'file_b.txt')));
+	assert(op.label, op.batch, b => b.some(e => (e.mask & FAN_RENAME) && e.old === '/file_a.txt' && e.new === '/file_b.txt'));
+
+	op = await doOp('mv /dir_b /dir_a/dir_b_moved', () => fs.rename(join(mnt, 'dir_b'), join(mnt, 'dir_a', 'dir_b_moved')));
+	assert(op.label, op.batch, b => b.some(e => (e.mask & FAN_RENAME) && (e.mask & FAN_ONDIR) && e.old === '/dir_b' && e.new === '/dir_a/dir_b_moved'));
+
+	op = await doOp('chmod 600 /file_b.txt', () => fs.chmod(join(mnt, 'file_b.txt'), 0o600));
+	assert(op.label, op.batch, b => hasEvent(b, FAN_ATTRIB, '/file_b.txt'));
+
+	op = await doOp('touch -m /file_b.txt', () => fs.utimes(join(mnt, 'file_b.txt'), new Date(), new Date()));
+	assert(op.label, op.batch, b => hasEvent(b, FAN_ATTRIB, '/file_b.txt'));
+
+	op = await doOp('chmod 755 /dir_a', () => fs.chmod(join(mnt, 'dir_a'), 0o755));
+	assert(op.label, op.batch, b => hasEvent(b, FAN_ATTRIB | FAN_ONDIR, '/dir_a'));
+
+	op = await doOp('rm /file_b.txt', () => fs.unlink(join(mnt, 'file_b.txt')));
+	assert(op.label, op.batch, b => hasEvent(b, FAN_DELETE, '/file_b.txt'));
+
+	op = await doOp('rm /dir_a/dir_b_moved/nested.txt', () => fs.unlink(join(mnt, 'dir_a', 'dir_b_moved', 'nested.txt')));
+	assert(op.label, op.batch, b => hasEvent(b, FAN_DELETE, '/dir_a/dir_b_moved/nested.txt'));
+
+	op = await doOp('rmdir /dir_a/dir_b_moved', () => fs.rmdir(join(mnt, 'dir_a', 'dir_b_moved')));
+	assert(op.label, op.batch, b => hasEvent(b, FAN_DELETE | FAN_ONDIR, '/dir_a/dir_b_moved'));
+
+	op = await doOp('rmdir /dir_a', () => fs.rmdir(join(mnt, 'dir_a')));
+	assert(op.label, op.batch, b => hasEvent(b, FAN_DELETE | FAN_ONDIR, '/dir_a'));
+
+	console.log('PASS');
+} catch (e) {
+	console.error(e.message);
+	process.exitCode = 1;
+} finally {
+	fa2json.kill();
+	await teardown();
+}