fetch-error-context (#33)

add context to NotFoundError

resolves #20

lib/error.ts

@@ -1,6 +1,6 @@
 export class NotFoundError extends Error {
-	constructor(url: URL) {
-		super(`Not found: ${url}`);
+	constructor(url: URL, context: string) {
+		super(`Not found (${context}): ${url}`);
 		this.name = "NotFoundError";
 	}
 }

lib/feed.test.ts

@@ -51,6 +51,7 @@ async function convertFeed404() {
 	const conf: ConvertConf = { raiBaseUrl, baseUrl, poolSize, fetch: fetchFn };
 	const expectedErr = new NotFoundError(
 		new URL("https://rai.dev/programmi/foo.json"),
+		"fetching feed",
 	);
 	await assert.rejects(convertFeed(conf, "programmi/foo.json"), expectedErr);
 }

lib/feed.ts

@@ -68,7 +68,7 @@ class FeedFetcher {
 		const res = await this.#fetch(url);
 		if (!res.ok) {
 			if (res.status === 404) {
-				throw new NotFoundError(url);
+				throw new NotFoundError(url, "fetching feed");
 			}
 			throw new Error(
 				`Failed to fetch ${url}: ${res.status} ${res.statusText}`.trim(),

lib/genres.test.ts

@@ -28,7 +28,10 @@ async function genresHtmlNotFound() {
 	};
 	const conf = confWithFetch(fetchFn);
 
-	const expectedErr = new NotFoundError(new URL("https://rai.dev/generi.json"));
+	const expectedErr = new NotFoundError(
+		new URL("https://rai.dev/generi.json"),
+		"fetching genres",
+	);
 	const p = genresHtml(conf);
 	await assert.rejects(p, expectedErr);
 }

lib/genres.ts

@@ -30,7 +30,7 @@ const fetchGenres = async (c: Conf) => {
 
 	if (!res.ok) {
 		if (res.status === 404) {
-			throw new NotFoundError(url);
+			throw new NotFoundError(url, "fetching genres");
 		}
 		throw new Error(
 			`Failed to fetch ${url} ${res.status} ${res.statusText}`.trim(),