From 3a4f4dc5b678117a6adb84099094ee8d5a71aa67 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sun, 30 Mar 2025 15:25:31 +0530
Subject: [PATCH] Add unit test for listener IPC

---
 src/calibre/gui2/listener.py   | 66 +++++++++++++++++++++++++++-------
 src/calibre/utils/run_tests.py |  2 ++
 2 files changed, 56 insertions(+), 12 deletions(-)

diff --git a/src/calibre/gui2/listener.py b/src/calibre/gui2/listener.py
index 0de7299bcd..c2903d5d00 100644
--- a/src/calibre/gui2/listener.py
+++ b/src/calibre/gui2/listener.py
@@ -11,7 +11,7 @@ from itertools import count
 
 from qt.core import QAbstractSocket, QLocalServer, pyqtSignal
 
-from calibre.utils.ipc import gui_socket_address
+from calibre.utils.ipc import gui_socket_address, socket_address
 
 
 def unix_socket(timeout=10):
@@ -90,25 +90,67 @@ def send_message_in_process(msg, address=None, timeout=5):
         ps.close()
 
 
-def send_message_via_worker(msg, address=None, timeout=5, wait_till_sent=False):
+def send_message_in_worker(address, timeout):
+    msg = sys.stdin.buffer.read()
+    send_message_in_process(msg, address, timeout)
+
+
+def send_message_via_worker(msg, address=None, timeout=5, wait_till_sent=True):
     # On Windows sending a message in a process that also is listening on the
     # same named pipe in a different thread deadlocks, so we do the actual sending in
     # a simple worker process
-    import json
-    import subprocess
-
-    from calibre.startup import get_debug_executable
-    cmd = get_debug_executable() + [
-        '-c', 'from calibre.gui2.listener import *; import sys, json;'
-        'send_message_in_process(sys.stdin.buffer.read(), address=json.loads(sys.argv[-2]), timeout=float(sys.argv[-1]))',
-        json.dumps(address), str(timeout)]
-    p = subprocess.Popen(cmd, stdin=subprocess.PIPE)
+    from calibre.utils.ipc.simple_worker import start_pipe_worker
     if isinstance(msg, str):
         msg = msg.encode('utf-8')
+    p = start_pipe_worker(f'from calibre.gui2.listener import *; send_message_in_worker({address!r}, {timeout!r})')
     with closing(p.stdin):
         p.stdin.write(msg)
     if wait_till_sent:
-        return p.wait(timeout=timeout) == 0
+        return p.wait(timeout=timeout + 2) == 0
+
+
+def listener_for_test(address):
+    from qt.core import QCoreApplication, QTimer
+    app = QCoreApplication([])
+    s = Listener(address=address, parent=app)
+    s.start_listening()
+    def got_message(msg):
+        if msg == b'quit':
+            app.quit()
+            return
+        sys.stdout.buffer.write(msg)
+        sys.stdout.buffer.write(os.linesep.encode())
+        sys.stdout.buffer.flush()
+    s.message_received.connect(got_message)
+    QTimer.singleShot(0, lambda: print('started', flush=True))
+    app.exec()
+
+
+def find_tests():
+    import unittest
+    class TestIPC(unittest.TestCase):
+
+        def test_listener_ipc(self):
+            from calibre.utils.ipc.simple_worker import start_pipe_worker
+            address = socket_address('test')
+            server = start_pipe_worker(f'from calibre.gui2.listener import *; listener_for_test({address!r})')
+            try:
+                self.assertEqual(server.stdout.readline().rstrip(), b'started')
+                for msg in 'one', 'two', 'three':
+                    send_message_in_process(msg, address=address)
+                    self.assertEqual(server.stdout.readline().rstrip(), msg.encode())
+                self.assertTrue(send_message_via_worker('hello, world!', address=address))
+                self.assertEqual(server.stdout.readline().rstrip(), b'hello, world!')
+                msg = '123456789' * 8192 * 10
+                send_message_in_process(msg, address=address)
+                self.assertEqual(server.stdout.readline().rstrip(), msg.encode())
+                send_message_in_process('quit', address=address)
+                server.wait(2)
+            finally:
+                server.kill()
+                server.wait()
+
+    return unittest.defaultTestLoader.loadTestsFromTestCase(TestIPC)
 
 
 def test():
diff --git a/src/calibre/utils/run_tests.py b/src/calibre/utils/run_tests.py
index acf3d56695..b13f2deacf 100644
--- a/src/calibre/utils/run_tests.py
+++ b/src/calibre/utils/run_tests.py
@@ -310,6 +310,8 @@ def find_tests(which_tests=None, exclude_tests=None):
         a(find_tests())
         from calibre.utils.safe_atexit import find_tests
         a(find_tests())
+        from calibre.gui2.listener import find_tests
+        a(find_tests())
         if iswindows:
             from calibre.utils.windows.wintest import find_tests
             a(find_tests())