feat: allow configurable news upstream

Author: AlisinaDevelo

.env.example

@@ -6,6 +6,7 @@ PORT=3000
 # Optional operations (see docs/OPERATIONS.md)
 # NODE_ENV=production
 # LOG_LEVEL=info
+# GNEWS_BASE_URL=https://gnews.io/api/v4
 # HTTP_TIMEOUT_MS=15000
 # SHUTDOWN_TIMEOUT_MS=10000
 # RATE_LIMIT_MAX=120

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Optional search filters for `lang`, `country`, `from`, `to`, and `sortBy`, with validation and normalized cache keys.
 - Prometheus metrics for article-search cache hit/miss behavior and upstream provider request latency/outcomes.
 - Curl-based `npm run smoke` check for a running instance.
+- Configurable `GNEWS_BASE_URL` for deterministic local integration tests and benchmarks.
 
 ### Security
 

README.md

@@ -1,6 +1,6 @@
 # news-api
 
-**Express + TypeScript** service that searches news through the [GNews API](https://gnews.io/). Searches support provider-backed filters for language, country, date range, and sort order. Identical normalized searches are cached (in-memory by default, or **Redis** when `REDIS_URL` is set) to protect quota and latency.
+**Express + TypeScript** service that searches news through the [GNews API](https://gnews.io/). Searches support provider-backed filters for language, country, date range, and sort order. Identical normalized searches are cached (in-memory by default, or **Redis** when `REDIS_URL` is set) to protect quota and latency. The upstream base URL is injectable for deterministic local integration tests and benchmarks.
 
 ## Production-oriented features
 

docs/OPERATIONS.md

@@ -8,6 +8,7 @@
 | `PORT` | `3000` | HTTP listen port. |
 | `NODE_ENV` | — | Use `production` in deployed environments. |
 | `LOG_LEVEL` | `info` (non-test) | Pino level (`trace`–`fatal`, or `silent`). |
+| `GNEWS_BASE_URL` | `https://gnews.io/api/v4` | Upstream provider base URL. Override only for local integration tests, benchmarks, or compatible provider mocks. |
 | `HTTP_TIMEOUT_MS` | `15000` | Outbound GNews request timeout (max `60000`). |
 | `SHUTDOWN_TIMEOUT_MS` | `10000` | Force-exit if `server.close` does not finish. |
 | `RATE_LIMIT_MAX` | `120` | Max requests per IP per window. |

src/config/upstream.ts

@@ -2,3 +2,15 @@ const raw = Number(process.env.HTTP_TIMEOUT_MS ?? 15_000);
 
 export const UPSTREAM_TIMEOUT_MS =
   Number.isFinite(raw) && raw > 0 ? Math.min(raw, 60_000) : 15_000;
+
+const DEFAULT_UPSTREAM_BASE_URL = "https://gnews.io/api/v4";
+
+export function resolveUpstreamBaseUrl(rawUrl = process.env.GNEWS_BASE_URL): string {
+  const value = rawUrl?.trim();
+  if (!value) {
+    return DEFAULT_UPSTREAM_BASE_URL;
+  }
+  return value.replace(/\/+$/, "");
+}
+
+export const UPSTREAM_BASE_URL = resolveUpstreamBaseUrl();

src/services/newsService.ts

@@ -2,7 +2,7 @@ import axios from "axios";
 import { Article } from "../types/article";
 import { HttpError } from "../errors/HttpError";
 import { getCacheStore } from "../cache/store";
-import { UPSTREAM_TIMEOUT_MS } from "../config/upstream";
+import { UPSTREAM_BASE_URL, UPSTREAM_TIMEOUT_MS } from "../config/upstream";
 import { ArticleSearchFilters, ArticleSearchOptions } from "../types/search";
 import {
   cacheEventsTotal,
@@ -11,7 +11,6 @@ import {
 } from "../metrics/register";
 
 const API_KEY = process.env.GNEWS_API_KEY;
-const BASE_URL = "https://gnews.io/api/v4";
 
 function normalizeArticles(data: unknown): Article[] {
   if (
@@ -63,7 +62,7 @@ export const fetchArticles = async (options: ArticleSearchOptions): Promise<Arti
   const stopUpstreamTimer = upstreamRequestDurationSeconds.startTimer();
   let articles: Article[];
   try {
-    const response = await axios.get<{ articles: Article[] }>(`${BASE_URL}/search`, {
+    const response = await axios.get<{ articles: Article[] }>(`${UPSTREAM_BASE_URL}/search`, {
       params: toProviderParams(options),
       timeout: UPSTREAM_TIMEOUT_MS,
       validateStatus: (s) => s >= 200 && s < 300,

test/upstream.test.ts

@@ -0,0 +1,15 @@
+import { describe, expect, it } from "vitest";
+import { resolveUpstreamBaseUrl } from "../src/config/upstream";
+
+describe("resolveUpstreamBaseUrl", () => {
+  it("defaults to GNews", () => {
+    expect(resolveUpstreamBaseUrl("")).toBe("https://gnews.io/api/v4");
+    expect(resolveUpstreamBaseUrl(undefined)).toBe("https://gnews.io/api/v4");
+  });
+
+  it("trims trailing slashes from custom upstreams", () => {
+    expect(resolveUpstreamBaseUrl(" http://127.0.0.1:4000/api/v4/// ")).toBe(
+      "http://127.0.0.1:4000/api/v4"
+    );
+  });
+});