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

test/lib/setup.mjs

@@ -0,0 +1,34 @@
+import { execSync, spawn } from 'node:child_process';
+import { mkdtempSync, mkdirSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+
+const FA2JSON = new URL('../../fa2json', import.meta.url).pathname;
+
+export async function setup() {
+	// Create image file and format
+	const img = execSync('mktemp /tmp/fa2json-test-XXXXXX.img').toString().trim();
+	execSync(`truncate -s 10M ${img}`);
+	execSync(`mkfs.ext4 -q ${img}`);
+
+	// Create mount point and mount
+	const mnt = execSync('mktemp -d /tmp/fa2json-mnt-XXXXXX').toString().trim();
+	execSync(`sudo mount ${img} ${mnt}`);
+
+	// Hand ownership to current user, then sync before fa2json starts
+	execSync(`sudo chown ${process.getuid()} ${mnt}`);
+	execSync('sync');
+
+	async function teardown() {
+		try { execSync(`sudo umount ${mnt}`); } catch {}
+		try { execSync(`rm -f ${img}`); } catch {}
+		try { execSync(`rmdir ${mnt}`); } catch {}
+	}
+
+	return { img, mnt, teardown };
+}
+
+export function spawnFa2json(mnt) {
+	const proc = spawn('sudo', [FA2JSON, mnt], { stdio: ['ignore', 'pipe', 'inherit'] });
+	return proc;
+}