fix(AIC-3572): treat a variation without _ldMeta.enabled as disabled

packages/client/src/launchdarkly_ai_server/lifecycle.py

@@ -532,13 +532,13 @@ async def extract_variation(
             f"Variation '{config_key}' returned None (flag may be disabled)."
         )
 
-    if isinstance(raw, dict) and raw.get("_ldMeta", {}).get("enabled") is False:
+    # Only an explicit ``_ldMeta.enabled`` counts as enabled (spec §3.10, as in JS and Go).
+    ld_meta = (raw.get("_ldMeta") or {}) if isinstance(raw, dict) else {}
+    if not isinstance(ld_meta, dict) or not ld_meta.get("enabled"):
         raise RuntimeError(f"Variation '{config_key}' is disabled.")
 
-    # Extract meta from _ldMeta if present
-    ld_meta = raw.get("_ldMeta", {}) if isinstance(raw, dict) else {}
     meta = {
-        "enabled": ld_meta.get("enabled", True),
+        "enabled": True,
         "variationKey": ld_meta.get("variationKey", ""),
         "version": ld_meta.get("version", 1),
         "mode": ld_meta.get("mode"),

packages/client/tests/test_lifecycle.py

@@ -967,3 +967,35 @@ async def test_never_raises_when_variation_throws(self) -> None:
         assert result["enabled"] is False
         assert result["config"] is None
         assert result["meta"] is None
+
+
+# ---------------------------------------------------------------------------
+# extract_variation — missing enabled flag
+# ---------------------------------------------------------------------------
+
+
+class TestExtractVariationMissingEnabled:
+    # Spec §3.10: only ``_ldMeta.enabled: true`` is enabled, as in JS and Go.
+    @pytest.mark.parametrize("ld_meta", [None, {}], ids=["no_ldMeta", "empty_ldMeta"])
+    async def test_raises_when_enabled_is_missing(
+        self, ld_meta: dict[str, Any] | None
+    ) -> None:
+        raw: dict[str, Any] = {
+            "model": {"name": "claude-3-5"},
+            "provider": {"name": "Anthropic"},
+            "instructions": "You are helpful.",
+        }
+        if ld_meta is not None:
+            raw["_ldMeta"] = ld_meta
+        stub = _make_stub_client()
+        stub.variation = AsyncMock(return_value=raw)
+        with patch.object(lifecycle_module, "_setup_telemetry", return_value=None):
+            await init_client(client=stub)
+        ctx = {"kind": "user", "key": "user-1"}
+        with patch(
+            "launchdarkly_ai_server.utils.to_ld_context",
+            side_effect=lambda _c, ctx: ctx,
+        ):
+            with pytest.raises(RuntimeError, match="'my-flag' is disabled"):
+                await lifecycle_module.extract_variation("my-flag", ctx)
+            assert (await inspect_config("my-flag", ctx))["enabled"] is False