Add pi-browser-harness ext (vendored 0.11.0, sharp dropped)

extensions/pi-browser-harness/src/daemon/spawn.ts

@@ -0,0 +1,120 @@
+import { spawn, type ChildProcess } from "node:child_process";
+import { access, unlink } from "node:fs/promises";
+import { existsSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+import { dirname, join } from "node:path";
+import { createConnection } from "node:net";
+import { DAEMON_SOCKET_PATH, serialize, type WireControl } from "./protocol";
+
+const moduleDir = dirname(fileURLToPath(import.meta.url));
+
+const isWindows = process.platform === "win32";
+
+// No-op on Windows: a named pipe is not a filesystem entry and unlinking a pipe path throws.
+const cleanupStaleSocket = (): void => {
+  if (isWindows) return;
+  unlink(DAEMON_SOCKET_PATH).catch(() => {});
+};
+
+export const daemonSocketMayExist = async (
+  platform: NodeJS.Platform = process.platform,
+  socketPath: string = DAEMON_SOCKET_PATH,
+): Promise<boolean> => {
+  if (platform === "win32") return true;
+  try {
+    await access(socketPath);
+    return true;
+  } catch {
+    return false;
+  }
+};
+
+export const isDaemonRunning = async (timeoutMs = 2_000): Promise<boolean> => {
+  if (!(await daemonSocketMayExist())) return false;
+
+  return new Promise((resolve) => {
+    let settled = false;
+    const done = (alive: boolean): void => {
+      if (settled) return;
+      settled = true;
+      resolve(alive);
+    };
+
+    const sock = createConnection(DAEMON_SOCKET_PATH);
+    const timer = setTimeout(() => {
+      sock.destroy();
+      cleanupStaleSocket();
+      done(false);
+    }, timeoutMs);
+
+    sock.on("connect", () => {
+      const regMsg: WireControl = { type: "control", action: "register", clientId: "_liveness_probe" };
+      sock.write(serialize(regMsg) + "\n");
+    });
+
+    sock.on("data", (chunk: Buffer) => {
+      const text = chunk.toString();
+      if (text.includes('"registered"')) {
+        clearTimeout(timer);
+        const deregMsg: WireControl = { type: "control", action: "deregister", clientId: "_liveness_probe" };
+        try { sock.write(serialize(deregMsg) + "\n"); } catch {}
+        sock.destroy();
+        done(true);
+      }
+    });
+
+    sock.on("error", () => {
+      clearTimeout(timer);
+      sock.destroy();
+      cleanupStaleSocket();
+      done(false);
+    });
+
+    // Closed without a 'registered' ack: the daemon is alive but rejected us, so do NOT unlink its socket.
+    sock.on("close", () => {
+      clearTimeout(timer);
+      done(false);
+    });
+  });
+};
+
+export const spawnDaemon = (): ChildProcess | null => {
+  const daemonScript = join(moduleDir, "index.ts");
+
+  // Windows npm binaries are `.cmd` shims, which only launch through a shell — spawning one directly yields EINVAL.
+  const tsxBinBase = join(moduleDir, "..", "..", "node_modules", ".bin", "tsx");
+  const tsxBin = isWindows ? `${tsxBinBase}.cmd` : tsxBinBase;
+  const hasLocalTsx = existsSync(tsxBin);
+
+  const cmd = hasLocalTsx ? tsxBin : isWindows ? "npx.cmd" : "npx";
+  const args = hasLocalTsx ? [daemonScript] : ["tsx", daemonScript];
+
+  // With shell: true Node passes the command line verbatim, so a path containing spaces must be quoted or it splits into tokens.
+  const quote = (s: string): string => (isWindows ? `"${s}"` : s);
+
+  const child = spawn(quote(cmd), args.map(quote), {
+    detached: true,
+    stdio: "ignore",
+    env: { ...process.env },
+    shell: isWindows,
+    windowsVerbatimArguments: isWindows,
+  });
+
+  child.unref();
+  return child;
+};
+
+export const ensureDaemon = async (timeoutMs = 10_000): Promise<boolean> => {
+  if (await isDaemonRunning()) return true;
+
+  const child = spawnDaemon();
+  if (!child) return false;
+
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    if (await isDaemonRunning()) return true;
+    await new Promise((r) => setTimeout(r, 200));
+  }
+
+  return false;
+};