[router] Add comprehensive E2E tests for Response API (#11988)

sgl-router/py_test/e2e_response_api/util.py

@@ -0,0 +1,82 @@
+"""
+Utility functions for Response API e2e tests.
+"""
+
+import os
+import signal
+import threading
+import unittest
+
+import psutil
+
+
+def kill_process_tree(parent_pid, include_parent: bool = True, skip_pid: int = None):
+    """
+    Kill the process and all its child processes.
+
+    Args:
+        parent_pid: PID of the parent process
+        include_parent: Whether to kill the parent process itself
+        skip_pid: Optional PID to skip during cleanup
+    """
+    # Remove sigchld handler to avoid spammy logs
+    if threading.current_thread() is threading.main_thread():
+        signal.signal(signal.SIGCHLD, signal.SIG_DFL)
+
+    if parent_pid is None:
+        parent_pid = os.getpid()
+        include_parent = False
+
+    try:
+        itself = psutil.Process(parent_pid)
+    except psutil.NoSuchProcess:
+        return
+
+    children = itself.children(recursive=True)
+    for child in children:
+        if child.pid == skip_pid:
+            continue
+        try:
+            child.kill()
+        except psutil.NoSuchProcess:
+            pass
+
+    if include_parent:
+        try:
+            itself.kill()
+        except psutil.NoSuchProcess:
+            pass
+
+
+class CustomTestCase(unittest.TestCase):
+    """
+    Custom test case base class with retry support.
+
+    This provides automatic test retry functionality based on environment variables.
+    """
+
+    def _callTestMethod(self, method):
+        """Override to add retry logic."""
+        max_retry = int(os.environ.get("SGLANG_TEST_MAX_RETRY", "0"))
+
+        if max_retry == 0:
+            # No retry, just run once
+            return super(CustomTestCase, self)._callTestMethod(method)
+
+        # Retry logic
+        for attempt in range(max_retry + 1):
+            try:
+                return super(CustomTestCase, self)._callTestMethod(method)
+            except Exception as e:
+                if attempt < max_retry:
+                    print(
+                        f"Test failed on attempt {attempt + 1}/{max_retry + 1}, retrying..."
+                    )
+                    continue
+                else:
+                    # Last attempt, re-raise the exception
+                    raise
+
+    def setUp(self):
+        """Print test method name at the start of each test."""
+        print(f"[Test Method] {self._testMethodName}", flush=True)