add pytest-xdist for running tests

Author: tylerhutcherson

conftest.py

@@ -8,27 +8,55 @@
 
 
 @pytest.fixture(scope="session", autouse=True)
-def redis_container():
-    # Set the default Redis version if not already set
+def redis_container(request):
+    """
+    Create a unique Compose project for each xdist worker by setting
+    COMPOSE_PROJECT_NAME. That prevents collisions on container/volume names.
+    """
+    # In xdist, the config has "workerid" in workerinput.  For the main (non-xdist)
+    # process, 'workerid' is often 'master' or something similar.
+    worker_id = request.config.workerinput.get("workerid", "master")
+
+    # Set the Compose project name so containers do not clash across workers
+    os.environ["COMPOSE_PROJECT_NAME"] = f"redis_test_{worker_id}"
     os.environ.setdefault("REDIS_VERSION", "edge")
 
-    compose = DockerCompose("tests", compose_file_name="docker-compose.yml", pull=True)
+    compose = DockerCompose(
+        context="tests",
+        compose_file_name="docker-compose.yml",
+        pull=True,
+    )
+
     compose.start()
 
+    # If you mapped the container port 6379:6379 in docker-compose.yml,
+    # you might have collisions across workers. If you rely on ephemeral
+    # host ports, remove the `ports:` block in docker-compose.yml and do:
     redis_host, redis_port = compose.get_service_host_and_port("redis", 6379)
-    redis_url = f"redis://{redis_host}:{redis_port}"
-    os.environ["REDIS_URL"] = redis_url
+    #redis_url = f"redis://{redis_host}:{redis_port}"
+    #os.environ["REDIS_URL"] = redis_url
 
     yield compose
 
     compose.stop()
+    # Optionally, clean up the COMPOSE_PROJECT_NAME you set:
+    os.environ.pop("COMPOSE_PROJECT_NAME", None)
+
 
 @pytest.fixture(scope="session")
-def redis_url():
-    return os.getenv("REDIS_URL", "redis://localhost:6379")
+def redis_url(redis_container):
+    """
+    Use the `DockerCompose` fixture to get host/port of the 'redis' service
+    on container port 6379 (mapped to an ephemeral port on the host).
+    """
+    host, port = redis_container.get_service_host_and_port("redis", 6379)
+    return f"redis://{host}:{port}"
 
 @pytest.fixture
 async def async_client(redis_url):
+    """
+    An async Redis client that uses the dynamic `redis_url`.
+    """
     client = await RedisConnectionFactory.get_async_redis_connection(redis_url)
     yield client
     try:
@@ -38,8 +66,11 @@ async def async_client(redis_url):
             raise
 
 @pytest.fixture
-def client():
-    conn = RedisConnectionFactory.get_redis_connection(os.environ["REDIS_URL"])
+def client(redis_url):
+    """
+    A sync Redis client that uses the dynamic `redis_url`.
+    """
+    conn = RedisConnectionFactory.get_redis_connection(redis_url)
     yield conn
     conn.close()