feat: map the engine DEFAULT reason to STATIC

Signed-off-by: wadii <wadii.zaim@flagsmith.com>

Author: Zaimwa9

README.md

@@ -104,7 +104,7 @@ details = of_client.get_string_details(
 )
 ```
 
-The hook records an exposure only when the flag resolved with a variant and reason `SPLIT` — a multivariate percentage-split assignment (enabled, identified, not offline). With `flagsmith` ≥6.2 resolution reasons come from the Flagsmith engine verbatim (e.g. `SPLIT; weight=30`); on older SDKs or APIs the provider infers them. Repeated evaluations are safe: duplicate exposures are deduplicated downstream.
+The hook records an exposure only when the flag resolved with a variant and reason `SPLIT` — a multivariate percentage-split assignment (enabled, identified, not offline). With `flagsmith` ≥6.2 resolution reasons come from the Flagsmith engine (e.g. `SPLIT; weight=30`; the engine's `DEFAULT` maps to `STATIC`); on older SDKs or APIs the provider infers them. Repeated evaluations are safe: duplicate exposures are deduplicated downstream.
 
 **2. Explicit `track()`.** Use the reserved `feature_flag.exposure` event name when you need to record an exposure decoupled from evaluation:
 

openfeature_flagsmith/provider.py

@@ -337,10 +337,14 @@ def _parse_reason(
         # Offline documents may be arbitrarily old.
         if getattr(self._client, "offline_mode", False):
             return Reason.STALE
-        # Engine reason, verbatim ("SPLIT; weight=30"), on flagsmith >=6.2.
-        engine_reason = getattr(flag, "reason", None)
-        if engine_reason is not None:
-            return engine_reason
+        client_reason = getattr(flag, "reason", None)
+        if client_reason is not None:
+            # The Flagsmith client's DEFAULT means the environment default
+            # state was served; OpenFeature reserves DEFAULT for the code
+            # default.
+            if str(client_reason).split(";", 1)[0].strip() == "DEFAULT":
+                return Reason.STATIC
+            return client_reason
         if evaluation_context.targeting_key:
             # A variant means a percentage-split assignment (SPLIT);
             # TARGETING_MATCH is reserved for segment matches.

tests/test_provider.py

@@ -652,7 +652,7 @@ def test_track_drops_reserved_dollar_names(
 @requires_engine_reasons
 @pytest.mark.parametrize(
     "engine_reason",
-    ["SPLIT; weight=50.0", "TARGETING_MATCH; segment=premium", "DEFAULT"],
+    ["SPLIT; weight=50.0", "TARGETING_MATCH; segment=premium"],
 )
 def test_engine_reason_is_forwarded_verbatim(
     mock_flagsmith_client: MagicMock, engine_reason: str
@@ -684,6 +684,36 @@ def test_engine_reason_is_forwarded_verbatim(
     assert result.reason == engine_reason
 
 
+@requires_engine_reasons
+def test_engine_default_reason_maps_to_static(
+    mock_flagsmith_client: MagicMock,
+) -> None:
+    # Given
+    key = "my_feature"
+    mock_flagsmith_client.get_identity_flags.return_value = Flags(
+        {
+            key: Flag(
+                feature_id=1,
+                feature_name=key,
+                enabled=True,
+                value="v",
+                reason="DEFAULT",
+            )
+        }
+    )
+    provider = FlagsmithProvider(mock_flagsmith_client)
+
+    # When
+    result = provider.resolve_string_details(
+        key,
+        default_value="default",
+        evaluation_context=EvaluationContext(targeting_key="user-1"),
+    )
+
+    # Then
+    assert result.reason == Reason.STATIC
+
+
 @requires_engine_reasons
 def test_disabled_reason_wins_over_engine_reason(
     mock_flagsmith_client: MagicMock,