GH-100192: add more `asyncio` subprocess tests (#100194)

Lib/test/test_asyncio/test_subprocess.py

@@ -686,6 +686,88 @@ class SubprocessMixin:
 
         self.assertIsNone(self.loop.run_until_complete(execute()))
 
+    async def check_stdout_output(self, coro, output):
+        proc = await coro
+        stdout, _ = await proc.communicate()
+        self.assertEqual(stdout, output)
+        self.assertEqual(proc.returncode, 0)
+        task = asyncio.create_task(proc.wait())
+        await asyncio.sleep(0)
+        self.assertEqual(task.result(), proc.returncode)
+
+    def test_create_subprocess_env_shell(self) -> None:
+        async def main() -> None:
+            cmd = f'''{sys.executable} -c "import os, sys; sys.stdout.write(os.getenv('FOO'))"'''
+            env = {"FOO": 'bar'}
+            proc = await asyncio.create_subprocess_shell(
+                cmd, env=env, stdout=subprocess.PIPE
+            )
+            return proc
+
+        self.loop.run_until_complete(self.check_stdout_output(main(), b'bar'))
+
+    def test_create_subprocess_env_exec(self) -> None:
+        async def main() -> None:
+            cmd = [sys.executable, "-c",
+                   "import os, sys; sys.stdout.write(os.getenv('FOO'))"]
+            env = {"FOO": 'baz'}
+            proc = await asyncio.create_subprocess_exec(
+                *cmd, env=env, stdout=subprocess.PIPE
+            )
+            return proc
+
+        self.loop.run_until_complete(self.check_stdout_output(main(), b'baz'))
+
+
+    def test_subprocess_concurrent_wait(self) -> None:
+        async def main() -> None:
+            proc = await asyncio.create_subprocess_exec(
+                *PROGRAM_CAT,
+                stdin=subprocess.PIPE,
+                stdout=subprocess.PIPE,
+            )
+            stdout, _ = await proc.communicate(b'some data')
+            self.assertEqual(stdout, b"some data")
+            self.assertEqual(proc.returncode, 0)
+            self.assertEqual(await asyncio.gather(*[proc.wait() for _ in range(10)]),
+                             [proc.returncode] * 10)
+
+        self.loop.run_until_complete(main())
+
+    def test_subprocess_consistent_callbacks(self):
+        events = []
+        class MyProtocol(asyncio.SubprocessProtocol):
+            def __init__(self, exit_future: asyncio.Future) -> None:
+                self.exit_future = exit_future
+
+            def pipe_data_received(self, fd, data) -> None:
+                events.append(('pipe_data_received', fd, data))
+
+            def pipe_connection_lost(self, fd, exc) -> None:
+                events.append('pipe_connection_lost')
+
+            def process_exited(self) -> None:
+                events.append('process_exited')
+                self.exit_future.set_result(True)
+
+        async def main() -> None:
+            loop = asyncio.get_running_loop()
+            exit_future = asyncio.Future()
+            code = 'import sys; sys.stdout.write("stdout"); sys.stderr.write("stderr")'
+            transport, _ = await loop.subprocess_exec(lambda: MyProtocol(exit_future),
+                                                      sys.executable, '-c', code, stdin=None)
+            await exit_future
+            transport.close()
+            self.assertEqual(events, [
+                ('pipe_data_received', 1, b'stdout'),
+                ('pipe_data_received', 2, b'stderr'),
+                'pipe_connection_lost',
+                'pipe_connection_lost',
+                'process_exited',
+            ])
+
+        self.loop.run_until_complete(main())
+
     def test_subprocess_communicate_stdout(self):
         # See https://github.com/python/cpython/issues/100133
         async def get_command_stdout(cmd, *args):