test: Add test for capturing output from multiple asyncio tasks in parallel

tests/test_capture_output.py

@@ -16,6 +16,33 @@ def test_sync_capture_line_by_line():
     assert "[stdout] Line 2" in output
     assert "[stderr] Error!" in output
 
+@pytest.mark.asyncio
+async def test_async_capture_parallel_tasks():
+    output = []
+    def callback(data):
+        output.append(data)
+
+    async def task1():
+        async with CaptureOutput(callback).async_context():
+            print("Task 1 - Line 1")
+            print("Task 1 - Line 2")
+            print("Task 1 - Error!", file=sys.stderr)
+
+    async def task2():
+        async with CaptureOutput(callback).async_context():
+            print("Task 2 - Line 1")
+            print("Task 2 - Line 2")
+            print("Task 2 - Error!", file=sys.stderr)
+
+    await asyncio.gather(task1(), task2())
+
+    assert "[stdout] Task 1 - Line 1" in output
+    assert "[stdout] Task 1 - Line 2" in output
+    assert "[stderr] Task 1 - Error!" in output
+    assert "[stdout] Task 2 - Line 1" in output
+    assert "[stdout] Task 2 - Line 2" in output
+    assert "[stderr] Task 2 - Error!" in output
+
 @pytest.mark.asyncio
 async def test_async_capture_line_by_line():
     output = []