test(falkordb): skip when the port answers but is not FalkorDB

tests/test_falkordb_integration.py

@@ -5,8 +5,10 @@
     docker run -d -p 6379:6379 falkordb/falkordb:latest
     uv run pytest tests/test_falkordb_integration.py -q
 
-The test auto-skips when the `falkordb` SDK is not installed or no FalkorDB is
-reachable, so it is a no-op in the default CI (which runs no external services).
+The test auto-skips when the `falkordb` SDK is not installed, no server is
+reachable, or the server that answers is not FalkorDB, so it is a no-op in the
+default CI (which runs no external services) and on a dev box that already has
+a plain Redis on 6379.
 Host/port are overridable via FALKORDB_HOST / FALKORDB_PORT.
 """
 from __future__ import annotations
@@ -26,13 +28,25 @@
 
 
 def _connect():
-    """Return a connected FalkorDB client, or skip if none is reachable."""
+    """Return a connected FalkorDB client, or skip if none is reachable.
+
+    ``ping()`` only proves *something* answers on the port. A plain Redis -- or
+    an SSH tunnel forwarding one -- replies to PING but has no graph module, so
+    the guard passed and the tests FAILED on `unknown command 'GRAPH.QUERY'`
+    instead of skipping. ``GRAPH.LIST`` identifies the service rather than mere
+    liveness: it is read-only, creates no keys, and anything that is not
+    FalkorDB/RedisGraph rejects it as an unknown command.
+    """
     try:
         db = falkordb.FalkorDB(host=HOST, port=PORT)
         db.connection.ping()
-        return db
     except Exception as e:  # pragma: no cover - depends on local environment
-        pytest.skip(f"no FalkorDB reachable at {HOST}:{PORT} ({e})")
+        pytest.skip(f"no server reachable at {HOST}:{PORT} ({e})")
+    try:
+        db.connection.execute_command("GRAPH.LIST")
+    except Exception as e:  # pragma: no cover - depends on local environment
+        pytest.skip(f"server at {HOST}:{PORT} is not FalkorDB, no graph module ({e})")
+    return db
 
 
 @pytest.fixture()