✨(backend) allow static feature flags without an analytics backend

Feature flags are read from the analytics backend. Without one,
NoOpAnalytics returned no flag, so "summary-enabled" was always off and
a self-hosted instance could not get automatic summaries without PostHog.

NoOpAnalytics now accepts a static "feature_flags" mapping through the
existing ANALYTICS_BACKEND_SETTINGS, and get_analytics() passes the
settings to it. Nothing changes when no flag is declared.

Fixes #1610

src/backend/core/analytics/__init__.py

@@ -39,7 +39,7 @@ def get_analytics() -> AnalyticsBackend:
     options = getattr(settings, "ANALYTICS_BACKEND_SETTINGS", {}) or {}
 
     if not dotted_path:
-        return NoOpAnalytics()
+        return NoOpAnalytics(**options)
 
     backend_class = import_string(dotted_path)
     return backend_class(**options)

src/backend/core/analytics/base.py

@@ -53,7 +53,23 @@ class AnalyticsBackend(ABC):
 
 
 class NoOpAnalytics(AnalyticsBackend):
-    """Default backend: silently discards everything."""
+    """
+    Default backend: discards events and serves static feature flags.
+
+    Feature flags can be declared without any analytics provider, e.g.:
+
+        ANALYTICS_BACKEND_SETTINGS = {"feature_flags": {"summary-enabled": True}}
+    """
+
+    def __init__(
+        self,
+        *,
+        feature_flags: Mapping[str, bool | str | None] | None = None,
+        **_kwargs: Any,
+    ) -> None:
+        # Other settings are ignored, so that settings meant for another
+        # backend never break an instance running without one.
+        self._feature_flags = dict(feature_flags or {})
 
     def identify(self, user: User, properties=None) -> None:
         """No-op: discards identify calls."""
@@ -63,3 +79,10 @@ class NoOpAnalytics(AnalyticsBackend):
 
     def shutdown(self) -> None:
         """No-op: nothing to flush."""
+
+    def get_user_feature_flags(
+        self,
+        user: User,
+    ) -> Mapping[UserFeatureFlag, bool | str | None]:
+        """Return the feature flags declared in settings, for any user."""
+        return self._feature_flags

src/backend/core/tests/analytics/test_base.py

@@ -0,0 +1,124 @@
+"""
+Unit tests for NoOpAnalytics and the analytics backend loader.
+"""
+
+# pylint: disable=redefined-outer-name,unused-argument
+
+import pytest
+
+from core.analytics import get_analytics
+from core.analytics.base import NoOpAnalytics
+from core.analytics.user_feature_flags import UserFeatureFlag
+from core.factories import UserFactory
+
+pytestmark = pytest.mark.django_db
+
+
+@pytest.fixture(autouse=True)
+def clear_analytics_cache():
+    """Clear the cached backend before and after each test."""
+    get_analytics.cache_clear()
+    yield
+    get_analytics.cache_clear()
+
+
+# ==============================
+# NoOpAnalytics
+# ==============================
+
+
+def test_noop_has_no_feature_flags_by_default():
+    """Should keep every feature flag disabled when none is declared."""
+    backend = NoOpAnalytics()
+    user = UserFactory()
+
+    assert not backend.get_user_feature_flags(user)
+    assert (
+        backend.is_user_feature_enabled(
+            user, UserFeatureFlag.TRANSCRIPT_SUMMARY_ENABLED
+        )
+        is False
+    )
+
+
+def test_noop_enables_declared_feature_flags():
+    """Should enable a feature flag declared as True."""
+    backend = NoOpAnalytics(feature_flags={"summary-enabled": True})
+    user = UserFactory()
+
+    assert backend.get_user_feature_flags(user) == {"summary-enabled": True}
+    assert (
+        backend.is_user_feature_enabled(
+            user, UserFeatureFlag.TRANSCRIPT_SUMMARY_ENABLED
+        )
+        is True
+    )
+
+
+@pytest.mark.parametrize("value", [False, None, "true"])
+def test_noop_only_enables_feature_flags_set_to_true(value):
+    """Should keep a feature flag disabled unless its value is exactly True."""
+    backend = NoOpAnalytics(feature_flags={"summary-enabled": value})
+    user = UserFactory()
+
+    assert (
+        backend.is_user_feature_enabled(
+            user, UserFeatureFlag.TRANSCRIPT_SUMMARY_ENABLED
+        )
+        is False
+    )
+
+
+def test_noop_ignores_unrelated_settings():
+    """Should accept settings meant for another backend without failing."""
+    backend = NoOpAnalytics(api_key="my-key", host="https://eu.i.posthog.com")
+
+    assert not backend.get_user_feature_flags(UserFactory())
+
+
+# ==============================
+# get_analytics
+# ==============================
+
+
+def test_get_analytics_defaults_to_noop_without_feature_flags(settings):
+    """Should return a no-op backend with no feature flag by default."""
+    settings.ANALYTICS_BACKEND = None
+    settings.ANALYTICS_BACKEND_SETTINGS = {}
+
+    backend = get_analytics()
+
+    assert isinstance(backend, NoOpAnalytics)
+    assert not backend.get_user_feature_flags(UserFactory())
+
+
+def test_get_analytics_passes_feature_flags_to_noop(settings):
+    """Should forward the feature flags when no backend is configured."""
+    settings.ANALYTICS_BACKEND = None
+    settings.ANALYTICS_BACKEND_SETTINGS = {"feature_flags": {"summary-enabled": True}}
+
+    backend = get_analytics()
+
+    assert isinstance(backend, NoOpAnalytics)
+    assert (
+        backend.is_user_feature_enabled(
+            UserFactory(), UserFeatureFlag.TRANSCRIPT_SUMMARY_ENABLED
+        )
+        is True
+    )
+
+
+def test_get_analytics_instantiates_configured_backend_with_settings(settings):
+    """Should instantiate the configured backend with its settings."""
+    settings.ANALYTICS_BACKEND = "core.analytics.base.NoOpAnalytics"
+    settings.ANALYTICS_BACKEND_SETTINGS = {"feature_flags": {"summary-enabled": True}}
+
+    backend = get_analytics()
+
+    assert isinstance(backend, NoOpAnalytics)
+    assert (
+        backend.is_user_feature_enabled(
+            UserFactory(), UserFeatureFlag.TRANSCRIPT_SUMMARY_ENABLED
+        )
+        is True
+    )