Review Provider

Review a Suggest Provider

Review the provider specified in $ARGUMENTS against Merino's patterns and best practices. If no provider is specified, ask which provider to review.

Step 1: Read the provider implementation

Read all files in apps/merino/merino/providers/suggest/{provider_name}/ including:

• provider.py
• backends/protocol.py (if exists)
• All backend implementations
• Any other files in the directory

Also read the provider's registration in apps/merino/merino/providers/suggest/manager.py (find the matching ProviderType and case block).

Read the provider's config section in apps/merino/merino/configs/default.toml.

Read tests in apps/merino/tests/unit/providers/suggest/{provider_name}/ and apps/merino/tests/integration/providers/suggest/{provider_name}/.

Step 2: Check against patterns

Review each of these areas and report findings. For each area, state PASS, WARN, or FAIL with an explanation.

Provider Class Structure

• Class is named Provider and extends BaseProvider
• __init__ stores self._name, self._enabled_by_default, self._query_timeout_sec
• __init__ calls super().__init__() (at end, without arguments, or with **kwargs)
• initialize() is async
• query() returns list[BaseSuggestion]
• shutdown() is implemented (even if no-op)
• logger = logging.getLogger(__name__) at module level

Error Handling

• query() catches backend errors and returns [] instead of crashing
• Errors are logged at warning level (not error unless truly fatal)
• If calling external APIs: does it need a circuit breaker? (check if Weather/FlightAware pattern applies)
• No bare except: clauses (should catch specific exceptions)

Query Normalization

• normalize_query() is implemented if the provider uses keyword matching
• At minimum strips whitespace and lowercases

Metrics

• Uses metrics_client for timing external calls (e.g., self.metrics_client.timeit(...))
• Provider-level metrics are tracked

Caching (if applicable)

• Uses RedisAdapter / NoCacheAdapter pattern from manager
• Cache TTLs are configurable via settings

Configuration

• Provider section exists in default.toml with type, backend, enabled_by_default, score, query_timeout_sec
• API keys/URLs in separate section (not under providers.*)
• Registered in ProviderType enum
• Has a case in _create_provider() factory

Custom Details

• If returning extra fields: uses CustomDetails pattern (not top-level fields on BaseSuggestion)
• Details model defined in custom_details.py

Backend Protocol (if applicable)

• Backend interface defined as a Protocol class
• Fake backend exists for testing
• Backend methods raise BackendError subclass on failures

Testing

• Unit tests exist for the provider
• Tests cover: initialization, happy path query, error handling, query normalization
• Backend mocked with mocker.AsyncMock(spec=BackendProtocol)
• All async tests have @pytest.mark.asyncio
• Tests use fixtures from conftest, not inline setup

Data Refresh (if applicable)

• Uses packages/merino-common/merino_common/utils/cron.py Job class for periodic refresh
• Cron task created with asyncio.create_task() in initialize()
• Has a _should_fetch() condition function
• Handles fetch failures gracefully (logs, doesn't crash)

Step 3: Report

Present findings as a checklist with PASS/WARN/FAIL for each area. Include:

• A summary of the provider's health (good / needs attention / significant issues)
• Specific actionable recommendations for any WARN or FAIL items
• Code snippets showing exactly what to fix, referencing existing providers as examples