fix(http_fetcher): show "no connection" only when offline

js/http_fetcher.mjs

@@ -21,10 +21,13 @@ const ERROR_TYPE_TO_TRANSLATION = {
 	RATE_LIMITED: "MODULE_ERROR_RATE_LIMITED",
 	SERVER_ERROR: "MODULE_ERROR_SERVER_ERROR",
 	CLIENT_ERROR: "MODULE_ERROR_CLIENT_ERROR",
-	NETWORK_ERROR: "MODULE_ERROR_NO_CONNECTION",
+	NETWORK_ERROR: "MODULE_ERROR_UNSPECIFIED",
 	UNKNOWN_ERROR: "MODULE_ERROR_UNSPECIFIED"
 };
 
+// Error codes meaning the device is offline, as opposed to a single server being unreachable
+const OFFLINE_ERROR_CODES = new Set(["EAI_AGAIN", "ENETDOWN", "ENETUNREACH"]);
+
 /**
  * HTTPFetcher - Centralized HTTP fetching with intelligent error handling
  *
@@ -357,7 +360,9 @@ class HTTPFetcher extends EventEmitter {
 			}
 		} catch (error) {
 			const isTimeout = error.name === "AbortError";
-			const message = isTimeout ? `Request timeout after ${this.timeout}ms` : `Network error: ${error.message}`;
+			// fetch only says "fetch failed", the actual reason (e.g. ENOTFOUND) is in the cause
+			const reason = error.cause?.code ?? error.message;
+			const message = isTimeout ? `Request timeout after ${this.timeout}ms` : `Network error: ${reason}`;
 
 			this.networkErrorCount = Math.min(this.networkErrorCount + 1, this.maxRetries);
 			const exhausted = this.networkErrorCount >= this.maxRetries;
@@ -385,6 +390,9 @@ class HTTPFetcher extends EventEmitter {
 				error,
 				requestUrl
 			);
+			if (OFFLINE_ERROR_CODES.has(error.cause?.code)) {
+				errorInfo.translationKey = "MODULE_ERROR_NO_CONNECTION";
+			}
 			this.emit("error", errorInfo);
 		} finally {
 			clearTimeout(timeoutId);

tests/unit/functions/http_fetcher_spec.mjs

@@ -89,10 +89,28 @@ describe("HTTPFetcher", () => {
 			const errorInfo = await errorPromise;
 
 			expect(errorInfo).toHaveProperty("errorType", "NETWORK_ERROR");
-			expect(errorInfo).toHaveProperty("translationKey", "MODULE_ERROR_NO_CONNECTION");
 			expect(errorInfo).toHaveProperty("url", TEST_URL);
 		});
 
+		it.each([
+			["EAI_AGAIN", "MODULE_ERROR_NO_CONNECTION"],
+			["ERR_TLS_CERT_ALTNAME_INVALID", "MODULE_ERROR_UNSPECIFIED"]
+		])("should report %s as %s and log the reason", async (code, translationKey) => {
+			const fetchSpy = vi.spyOn(globalThis, "fetch").mockRejectedValue(new TypeError("fetch failed", { cause: Object.assign(new Error(), { code }) }));
+			fetcher = new HTTPFetcher({ url: TEST_URL, reloadInterval: 60000 });
+
+			const errorPromise = new Promise((resolve) => {
+				fetcher.on("error", resolve);
+			});
+
+			await fetcher.fetch();
+			const errorInfo = await errorPromise;
+			fetchSpy.mockRestore();
+
+			expect(errorInfo.translationKey).toBe(translationKey);
+			expect(errorInfo.message).toBe(`Network error: ${code}`);
+		});
+
 		it("should emit error event on timeout", async () => {
 			server.use(
 				http.get(TEST_URL, async () => {