rm-hull / fuel-prices-api / 22810208105

46%

push

github

feat: add fuel price snapshot statistics API and metrics (#28)

* feat: add fuel price snapshot statistics API and metrics

- Introduced `/v1/fuel-prices/snapshot-stats` endpoint.
- Added Prometheus gauge collector for real-time fuel statistics.
- Implemented memoized repository caching for stats queries.
- Updated `.vscode/launch.json` with required build tags.

```mermaid
graph TD
    A[API Request] --> B[Routes: SnapshotStats]
    B --> C[Repository: SnapshotStats]
    C --> D{Cache?}
    D -- Hit --> E[Return Cached Data]
    D -- Miss --> F[SQL Query]
    F --> G[Update Cache]
    G --> E
    C -- Metrics Loop --> H[Prometheus Collector]
```

* feat: refactor metrics tracking and separation

- Separated client HTTP metrics from fuel price statistics.
- Simplified `fuelPricesGaugeCollector` implementation.
- Implemented `ClientFetchMetrics` to track API request
  latencies, status codes, and items fetched.

```mermaid
graph LR
    subgraph Metrics
        A[ClientFetchMetrics] --> B(HTTP Latency)
        A --> C(Status Codes)
        A --> D(Items Total)
    end
    subgraph Stats
        E[FuelPricesCollector] --> F(Price Statistics)
    end
```

* refactor: scope snapshot variable inside loop

Move the `snapshot` variable declaration inside the `rows.Next()` loop
to ensure a fresh instance is used for each iteration, preventing
potential data leaks or overwrite issues across rows.

1 of 81 new or added lines in 6 files covered. (1.23%)

204 of 1168 relevant lines covered (17.47%)

0.19 hits per line