Fixed PreToolUse and Stop hook HTTP 502 errors (regression in claude-code 2.1.118)

CHANGELOG.md

@@ -1,3 +1,4 @@
+- Fixed PreToolUse and Stop hook HTTP 502 errors (regression in claude-code 2.1.118)
 - Fixed toolbar button focusing an existing session tab instead of opening a new one when all open tabs have active sessions
 
 # 0.21.54 (2026-04-22)

claude-launch-tests/test_hook_concurrent.py

@@ -0,0 +1,234 @@
+#!/usr/bin/env python3
+"""Verify that concurrent PreToolUse hook requests are all served without 502 errors.
+
+Regression test for the thread-exhaustion bug in HookServlet: when multiple
+Write hooks fire simultaneously (each blocking a Jetty thread waiting for
+user approval), subsequent hook or Stop hook requests were returned as HTTP 502.
+
+The test uses a mock hook server that delays each response by DELAY_SECONDS
+(simulating the user taking time to approve/reject in the diff dialog), then
+eventually responds with "allow". Claude is asked to write several files in one
+prompt; all hooks should get 200 responses and the PTY output must contain no
+"502" errors.
+
+Exit codes:
+    0 – PASS: all hooks received 200, no 502 in PTY output
+    1 – FAIL
+"""
+
+import http.server
+import json
+import os
+import pathlib
+import select
+import signal
+import socket
+import subprocess
+import sys
+import tempfile
+import threading
+import time
+import pty
+
+# ── tunables ──────────────────────────────────────────────────────────────────
+
+DELAY_SECONDS   = 3   # seconds each hook response is delayed (simulates user think-time)
+EXPECTED_HOOKS  = 3   # number of files claude is asked to write
+TIMEOUT_SECONDS = 90  # total test timeout
+
+# ── hook server ───────────────────────────────────────────────────────────────
+
+hooks_received  = []
+hooks_lock      = threading.Lock()
+
+ALLOW_JSON = json.dumps({
+    "hookSpecificOutput": {
+        "hookEventName": "PreToolUse",
+        "permissionDecision": "allow"
+    }
+}).encode()
+
+
+class DelayedHookHandler(http.server.BaseHTTPRequestHandler):
+    """Delays the allow response by DELAY_SECONDS to simulate pending user approval."""
+
+    def log_message(self, fmt, *args):
+        pass
+
+    def do_POST(self):
+        length = int(self.headers.get("Content-Length", 0))
+        raw = self.rfile.read(length)
+        try:
+            body = json.loads(raw)
+        except Exception:
+            body = {"raw": raw.decode(errors="replace")}
+
+        with hooks_lock:
+            idx = len(hooks_received) + 1
+            hooks_received.append(body)
+        tool = body.get("tool_name", "?")
+        print(f"[hook #{idx}] received: tool={tool}", flush=True)
+
+        # Simulate the user taking DELAY_SECONDS to click Accept in the diff dialog
+        time.sleep(DELAY_SECONDS)
+
+        self.send_response(200)
+        self.send_header("Content-Type", "application/json")
+        self.send_header("Content-Length", str(len(ALLOW_JSON)))
+        self.end_headers()
+        self.wfile.write(ALLOW_JSON)
+        print(f"[hook #{idx}] responded 200 allow", flush=True)
+
+
+class ThreadedHTTPServer(http.server.ThreadingHTTPServer):
+    """Serves each hook request in its own thread — mirrors the plugin's Jetty config."""
+    pass
+
+
+def free_port():
+    with socket.socket() as s:
+        s.bind(("127.0.0.1", 0))
+        return s.getsockname()[1]
+
+
+HOOK_PORT = free_port()
+hook_server = ThreadedHTTPServer(("127.0.0.1", HOOK_PORT), DelayedHookHandler)
+threading.Thread(target=hook_server.serve_forever, daemon=True).start()
+print(f"[test] hook server on port {HOOK_PORT}, delay={DELAY_SECONDS}s per hook", flush=True)
+
+# ── work directory ────────────────────────────────────────────────────────────
+
+workdir = tempfile.mkdtemp(prefix="hook_concurrent_")
+claude_dir = os.path.join(workdir, ".claude")
+os.makedirs(claude_dir, exist_ok=True)
+
+settings = {
+    "hooks": {
+        "PreToolUse": [{
+            "matcher": "Edit|Write|MultiEdit",
+            "hooks": [{"type": "http", "url": f"http://127.0.0.1:{HOOK_PORT}/hook"}]
+        }]
+    }
+}
+settings_path = os.path.join(claude_dir, "settings.local.json")
+with open(settings_path, "w") as f:
+    json.dump(settings, f, indent=2)
+
+print(f"[test] workdir: {workdir}", flush=True)
+
+# ── spawn Claude in TUI mode ──────────────────────────────────────────────────
+
+master_fd, slave_fd = pty.openpty()
+env = os.environ.copy()
+env["TERM"] = "xterm-256color"
+proc = subprocess.Popen(
+    ["claude", "--dangerously-skip-permissions"],
+    cwd=workdir,
+    stdin=slave_fd,
+    stdout=slave_fd,
+    stderr=slave_fd,
+    env=env,
+    preexec_fn=os.setsid,
+    close_fds=True,
+)
+os.close(slave_fd)
+
+pty_output_parts = []
+pty_lock = threading.Lock()
+stop_reader = threading.Event()
+
+
+def reader():
+    while not stop_reader.is_set():
+        try:
+            r, _, _ = select.select([master_fd], [], [], 0.5)
+            if r:
+                chunk = os.read(master_fd, 4096).decode("utf-8", errors="replace")
+                with pty_lock:
+                    pty_output_parts.append(chunk)
+                print(chunk, end="", flush=True)
+        except OSError:
+            break
+
+
+reader_thread = threading.Thread(target=reader, daemon=True)
+reader_thread.start()
+
+# Wait for initial prompt (trust warning / input ready)
+time.sleep(5)
+os.write(master_fd, b"2")   # accept bypass warning if present
+time.sleep(3)
+
+# Ask Claude to write three files in a single prompt so hooks fire concurrently
+prompt = (
+    "Write three files: file1.txt containing 'alpha', "
+    "file2.txt containing 'beta', "
+    "file3.txt containing 'gamma'. "
+    "Just create them, no explanation."
+)
+print(f"\n[test] sending prompt", flush=True)
+os.write(master_fd, prompt.encode() + b"\r")
+
+# Wait long enough for all DELAY_SECONDS-delayed hooks to complete
+deadline = time.time() + TIMEOUT_SECONDS
+while time.time() < deadline:
+    with hooks_lock:
+        n = len(hooks_received)
+    if n >= EXPECTED_HOOKS:
+        break
+    time.sleep(1)
+
+# Give claude a moment to finish writing
+time.sleep(5)
+
+# ── teardown ──────────────────────────────────────────────────────────────────
+
+stop_reader.set()
+proc.send_signal(signal.SIGTERM)
+time.sleep(1)
+hook_server.shutdown()
+reader_thread.join(timeout=3)
+
+with pty_lock:
+    pty_output = "".join(pty_output_parts)
+
+# ── verdict ───────────────────────────────────────────────────────────────────
+
+print("\n" + "=" * 60, flush=True)
+
+with hooks_lock:
+    n_hooks = len(hooks_received)
+
+# Check for 502 error text in PTY output
+error_patterns = ["HTTP 502", "502 Bad Gateway", "hook error"]
+found_errors = [p for p in error_patterns if p.lower() in pty_output.lower()]
+
+passed = True
+
+if n_hooks < EXPECTED_HOOKS:
+    print(f"FAIL: only {n_hooks}/{EXPECTED_HOOKS} hooks received within {TIMEOUT_SECONDS}s")
+    passed = False
+else:
+    print(f"OK: {n_hooks}/{EXPECTED_HOOKS} hooks received")
+
+if found_errors:
+    print(f"FAIL: PTY output contains error pattern(s): {found_errors}")
+    passed = False
+else:
+    print("OK: no 502/hook errors in PTY output")
+
+# Verify the files were actually written
+for fname in ("file1.txt", "file2.txt", "file3.txt"):
+    fpath = pathlib.Path(workdir) / fname
+    if fpath.exists():
+        print(f"OK: {fname} exists")
+    else:
+        print(f"WARN: {fname} not found (hook may have been delayed past claude timeout)")
+
+print("=" * 60, flush=True)
+if passed:
+    print("\nRESULT: PASS")
+    sys.exit(0)
+else:
+    print("\nRESULT: FAIL")
+    sys.exit(1)