Merge branch 'develop' into na/web/message-read-notifs

Author: nabramow

app/backend/src/couchers/context.py

@@ -2,6 +2,8 @@
 
 import grpc
 
+from couchers import experimentation
+from couchers.config import config
 from couchers.i18n import LocalizationContext
 
 if TYPE_CHECKING:
@@ -179,6 +181,36 @@ def token(self) -> str:
     def localization(self) -> LocalizationContext:
         return self.__localization
 
+    # Feature-flag evaluation methods mirror the OpenFeature evaluation API. The in-code default is
+    # honored even for flags not yet set up in GrowthBook, since get_feature_value falls back to it.
+    def get_boolean_value(self, flag_key: str, default: bool) -> bool:
+        if config["EXPERIMENTATION_PASS_ALL_GATES"]:
+            return True
+        return self._get_feature_value(flag_key, default)
+
+    def get_string_value(self, flag_key: str, default: str) -> str:
+        return self._get_feature_value(flag_key, default)
+
+    def get_integer_value(self, flag_key: str, default: int) -> int:
+        return self._get_feature_value(flag_key, default)
+
+    def get_float_value(self, flag_key: str, default: float) -> float:
+        return self._get_feature_value(flag_key, default)
+
+    def get_object_value[T](self, flag_key: str, default: T) -> T:
+        return self._get_feature_value(flag_key, default)
+
+    def _get_feature_value[T](self, flag_key: str, default: T) -> T:
+        if not config["EXPERIMENTATION_ENABLED"]:
+            return default
+        return self._get_growthbook().get_feature_value(flag_key, default)  # type: ignore[no-any-return]
+
+    def _get_growthbook(self) -> GrowthBook:
+        if self._growthbook is None:
+            # _user_id is None when logged out: evaluate anonymously, falling through to defaults.
+            self._growthbook = experimentation._create_evaluator(self._user_id)
+        return self._growthbook
+
 
 def make_interactive_context(
     grpc_context: grpc.ServicerContext,

app/backend/src/couchers/db.py

@@ -6,6 +6,7 @@
 from contextlib import contextmanager
 from os import getpid
 from threading import get_ident
+from typing import TYPE_CHECKING
 
 from alembic import command
 from alembic.config import Config
@@ -19,7 +20,6 @@
 
 from couchers.config import config
 from couchers.constants import SERVER_THREADS, WORKER_THREADS
-from couchers.context import CouchersContext
 from couchers.models import (
     Cluster,
     ClusterRole,
@@ -33,6 +33,9 @@
 )
 from couchers.sql import where_users_column_visible
 
+if TYPE_CHECKING:
+    from couchers.context import CouchersContext
+
 # Register psycopg (psycopg3) as the default driver for postgresql:// URLs
 # This must happen before any engine is created
 registry.register("postgresql", "sqlalchemy.dialects.postgresql.psycopg", "PGDialect_psycopg")

app/backend/src/couchers/experimentation.py

@@ -2,12 +2,17 @@
 Experimentation framework for feature flags and experiments.
 
 Uses GrowthBook under the hood, but abstracts the implementation details.
+
+Don't evaluate flags by calling into this module directly - go through the CouchersContext methods
+(context.get_boolean_value, get_string_value, etc.), which own the per-request evaluator cache and
+the enabled / pass-all-gates gating. The underscore-prefixed helpers here are internal to that
+wiring; setup_experimentation() is the only public entry point, called once at process startup.
 """
 
 import json
 import logging
 import threading
-from typing import TYPE_CHECKING, Any
+from typing import Any
 
 import urllib3
 from growthbook import GrowthBook
@@ -18,9 +23,6 @@
 from couchers.db import session_scope
 from couchers.models.logging import ExperimentExposure
 
-if TYPE_CHECKING:
-    from couchers.context import CouchersContext
-
 logger = logging.getLogger(__name__)
 
 _REFRESH_INTERVAL_SECONDS = 60
@@ -110,13 +112,6 @@ def setup_experimentation() -> None:
     logger.info(f"Experimentation integration test: gate 'test_growthbook_integration' = {test_gate_result}")
 
 
-def _check_initialized() -> None:
-    if config["EXPERIMENTATION_ENABLED"] and not _initialized:
-        raise ExperimentationNotInitializedError(
-            "Experimentation is not initialized - call setup_experimentation() first"
-        )
-
-
 def _record_exposure(user_id: int, experiment: Experiment, result: Result, **_: Any) -> None:
     data = {
         "experiment_name": experiment.name,
@@ -144,59 +139,34 @@ def _record_exposure(user_id: int, experiment: Experiment, result: Result, **_:
         session.execute(stmt)
 
 
-def _get_growthbook(context: CouchersContext) -> GrowthBook:
+def _create_evaluator(user_id: int | None) -> GrowthBook:
     """
-    Get or create a cached GrowthBook instance for the given context.
-
-    Reads the in-memory feature snapshot maintained by the background refresh
-    thread - never does HTTP from the request path. Constructing without
-    `client_key` keeps the GrowthBook a pure evaluator: no callback
-    registration on the library's process-wide singleton.
-    """
-    gb = context._growthbook
-    if gb is None:
-        with _state_lock:
-            features = _state["features"]
-            saved_groups = _state["savedGroups"]
-
-        user_id = context.user_id
-
-        def on_experiment_viewed(experiment: Experiment, result: Result, **kwargs: Any) -> None:
-            _record_exposure(user_id, experiment, result)
-
-        gb = GrowthBook(
-            attributes={"id": str(user_id)},
-            features=features,
-            savedGroups=saved_groups,
-            on_experiment_viewed=on_experiment_viewed,
-        )
-        context._growthbook = gb
-    return gb
+    Build a per-request GrowthBook evaluator over the current feature snapshot.
 
+    Pass user_id=None for an anonymous (logged-out) evaluation: with no `id` attribute GrowthBook
+    can't bucket the user, so experiments and percentage rollouts are skipped and flags fall
+    through to their defaults. No exposure is recorded without a user.
 
-def check_gate(context: CouchersContext, gate_name: str) -> bool:
+    Reads the in-memory snapshot maintained by the background refresh thread - never does HTTP
+    from the request path. Constructing without `client_key` keeps the GrowthBook a pure
+    evaluator: no callback registration on the library's process-wide singleton. The caller is
+    responsible for caching this for the lifetime of a request.
     """
-    Check if a feature gate is enabled for the user in this context.
-
-    Returns False if experimentation is disabled, True if EXPERIMENTATION_PASS_ALL_GATES is set.
-    """
-    _check_initialized()
-    if config["EXPERIMENTATION_PASS_ALL_GATES"]:
-        return True
-    if not config["EXPERIMENTATION_ENABLED"]:
-        return False
-    return _get_growthbook(context).is_on(gate_name)
-
+    if not _initialized:
+        raise ExperimentationNotInitializedError(
+            "Experimentation is not initialized - call setup_experimentation() first"
+        )
+    with _state_lock:
+        features = _state["features"]
+        saved_groups = _state["savedGroups"]
 
-def get_feature_value[T](context: CouchersContext, feature_name: str, default: T) -> T:
-    """
-    Get the value of a feature for the user in this context.
+    def on_experiment_viewed(experiment: Experiment, result: Result, **kwargs: Any) -> None:
+        if user_id is not None:
+            _record_exposure(user_id, experiment, result)
 
-    Use this for non-boolean features: strings, numbers, dicts, experiment variations,
-    dynamic configs - anything other than a simple on/off gate. The default's type
-    determines the return type and is returned verbatim when experimentation is disabled.
-    """
-    _check_initialized()
-    if not config["EXPERIMENTATION_ENABLED"]:
-        return default
-    return _get_growthbook(context).get_feature_value(feature_name, default)  # type: ignore[no-any-return]
+    return GrowthBook(
+        attributes={"id": str(user_id)} if user_id is not None else {},
+        features=features,
+        savedGroups=saved_groups,
+        on_experiment_viewed=on_experiment_viewed,
+    )

app/backend/src/couchers/servicers/account.py

@@ -27,7 +27,6 @@
     verify_token,
 )
 from couchers.event_log import log_event
-from couchers.experimentation import check_gate
 from couchers.helpers.completed_profile import has_completed_profile
 from couchers.helpers.geoip import geoip_approximate_location
 from couchers.helpers.strong_verification import get_strong_verification_fields
@@ -169,7 +168,7 @@ def GetAccountInfo(
 
         # Test experimentation integration - check if user is in the test gate
         # Create 'test_growthbook_integration' in GrowthBook to test
-        test_gate = check_gate(context, "test_growthbook_integration")
+        test_gate = context.get_boolean_value("test_growthbook_integration", default=False)
         logger.info(f"Experimentation gate 'test_growthbook_integration' for user {user.id}: {test_gate}")
 
         should_show_donation_banner = DONATION_DRIVE_START is not None and (

app/backend/src/couchers/servicers/bugs.py

@@ -58,6 +58,7 @@ def ReportBug(
             f"**Backend version**: `{self._version()}`\n"
             f"**Frontend version**: `{request.frontend_version}`\n"
             f"**User Agent**: `{request.user_agent}`\n"
+            f"**Locale**: `{context.localization.locale}`\n"
             f"**Screen resolution**: {request.screen_resolution.width}x{request.screen_resolution.height}\n"
             f"**Page**: {request.page}\n"
             f"**User**: {user_details}"

app/backend/src/couchers/sql.py

@@ -4,7 +4,6 @@
 from sqlalchemy.orm import InstrumentedAttribute, aliased
 from sqlalchemy.sql import Select, exists, union
 
-from couchers.context import CouchersContext
 from couchers.models import (
     ModerationState,
     ModerationVisibility,
@@ -16,6 +15,7 @@
 from couchers.utils import is_valid_email, is_valid_user_id, is_valid_username
 
 if TYPE_CHECKING:
+    from couchers.context import CouchersContext
     from couchers.materialized_views import LiteUser
     from couchers.models.moderation import ModeratedContent
 

app/backend/src/tests/test_bugs.py

@@ -54,6 +54,7 @@ def dud_post(url, auth, json):
 **Backend version**: `{config["VERSION"]}`
 **Frontend version**: `frontend_version`
 **User Agent**: `user_agent`
+**Locale**: `en`
 **Screen resolution**: 1920x1080
 **Page**: page
 **User**: <not logged in>""".strip()
@@ -114,6 +115,7 @@ def dud_post(url, auth, json):
 **Backend version**: `{config["VERSION"]}`
 **Frontend version**: `frontend_version`
 **User Agent**: `user_agent`
+**Locale**: `en`
 **Screen resolution**: 390x844
 **Page**: page
 **User**: [@testing_user](http://localhost:3000/user/testing_user) (1)""".strip()

app/backend/src/tests/test_experimentation.py

@@ -0,0 +1,43 @@
+import pytest
+
+from couchers import experimentation
+from couchers.config import config
+from couchers.context import make_background_user_context, make_logged_out_context
+from couchers.i18n import LocalizationContext
+
+
+@pytest.fixture
+def experimentation_snapshot(monkeypatch):
+    """Enable experimentation with an in-memory feature snapshot for evaluation."""
+    monkeypatch.setattr(experimentation, "_initialized", True)
+    features = {
+        # A rollout with explicit coverage: bucketing needs a hash, so anonymous (logged-out) users
+        # are excluded even at 100% coverage and get the feature's default value instead.
+        "rollout_flag": {"defaultValue": "control", "rules": [{"force": "treatment", "coverage": 1.0}]},
+        # A global force with no coverage: applies to everyone, including anonymous users.
+        "global_flag": {"defaultValue": False, "rules": [{"force": True}]},
+    }
+    monkeypatch.setattr(experimentation, "_state", {"features": features, "savedGroups": {}})
+    monkeypatch.setitem(config, "EXPERIMENTATION_ENABLED", True)
+    monkeypatch.setitem(config, "EXPERIMENTATION_PASS_ALL_GATES", False)
+
+
+def test_logged_in_user_is_bucketed_into_rollout(experimentation_snapshot):
+    context = make_background_user_context(123)
+    assert context.get_string_value("rollout_flag", "fallback") == "treatment"
+
+
+def test_anonymous_user_excluded_from_rollout_gets_feature_default(experimentation_snapshot):
+    context = make_logged_out_context(LocalizationContext.en_utc())
+    # Previously this raised NotLoggedInContextException via context.user_id.
+    assert context.get_string_value("rollout_flag", "fallback") == "control"
+
+
+def test_anonymous_user_still_gets_global_force_on_flag(experimentation_snapshot):
+    context = make_logged_out_context(LocalizationContext.en_utc())
+    assert context.get_boolean_value("global_flag", default=False) is True
+
+
+def test_unknown_feature_returns_in_code_default(experimentation_snapshot):
+    context = make_logged_out_context(LocalizationContext.en_utc())
+    assert context.get_string_value("does_not_exist", "my_default") == "my_default"

docs/meetings/dev/2026-05-22.md

@@ -0,0 +1,25 @@
+# Weekly Dev meeting
+
+When: 22/5/26, 12:30 UTC.
+Present: Aapeli, Bruna V, Chris K, Dale, Darren, Jesse, Kevin, Nick, Nicole, Valeriia
+Scribe: Nicole
+
+# Notes
+- Nicole is looking into US/EU/UK grant options for Couchers.
+- 2100+ downloads on Android, 1300+ on iOS, good reviews so far in the app stores
+- Our growth rate per day has tripled since Couchsurfing's update
+- Intros - welcome Bruna V!
+- We really need messaging rate limiting
+- Yay or Nay: Confirmation dialog for friend requests. Vote: Yay.
+- Aapeli is comparing GrowthBook to Statsig for the purpose of feature flags and feature experiments
+- How to handle people not noticing "My Home" section to fill out - combine them to one page? Add a reminder? Let's start with a reminder and see if it helps.
+
+* What everyone's working on:
+- Jesse: Working closely with Aapeli on improving moderation tooling stuff, especially making it more scalable.  Funnel feedback from support and Reddit about bugs and feature requests to us. Next: Working with Nick a lot to train him on our moderation tooling.
+- Chris K: Translations, feature testing, merchandise. Next: Same things.
+- Kevin: Helped replicate some bugs, tested decline flow feature. Next: Will pick up UI fix bug.
+- Valeriia: Was sick. Will find a new ticket next.
+- Aapeli: Working on moderation and support infrastructure and experiments. Got mobile dev environment running and has a mobile fix. Next: Will iron out moderation tools with Jesse and Nick, metrics for mobile app, wants to measure who is push request reachable.
+- Nick: Will meet with Jesse to go over moderation stuff.
+- Bruna: Will read the READMEs and familiarize herself with the codebase.
+- Nicole: Non-tech: Writing newsletters, blog posts, social media and LinkedIn posts about mobile release. Opened draft for spring release newsletter to go out this weekend, started looking in grants and funding options for Couchers, business verified our TikTok account. Tech: Merged backend and frontend for dashboard discussions widget, removed event `maybe_going` from backend and frontend, added mobile app badges to landing page and footer, PR open to improve decline flow, pushed some changes to update and edit discussions/replies, UI fixes. Next: Will start next mobile version bug fixes v1.1.20, try and get decline flow and edit/update discussions merged, do social media graphics and send out release v1.3.0 newsletter. If I finish all that, go back to public trips.