Add option --no_parallel

src/tribler-core/tribler_core/conftest.py

@@ -310,3 +310,21 @@ async def download_manager(tmp_path_factory):
     download_manager.initialize()
     yield download_manager
     await download_manager.shutdown()
+
+
+def pytest_addoption(parser):
+    # Documentation on pytest, "how to skip a test":
+    # https://docs.pytest.org/en/6.2.x/example/simple.html#control-skipping-of-tests-according-to-command-line-option
+    parser.addoption('--no_parallel', action='store_true', dest="no_parallel",
+                     default=False, help="run no_parallel tests")
+
+
+def pytest_collection_modifyitems(config, items):
+    # Documentation on pytest, "how to skip a test":
+    # https://docs.pytest.org/en/6.2.x/example/simple.html#control-skipping-of-tests-according-to-command-line-option
+    if config.getoption("--no_parallel"):
+        return
+    skip = pytest.mark.skip(reason="need --no_parallel option to run")
+    for item in items:
+        if "no_parallel" in item.keywords:
+            item.add_marker(skip)