Normalize double slashes into single in Workers Assets

Author: WalshyDev

packages/workers-shared/asset-worker/src/handler.ts

@@ -18,7 +18,10 @@ export const handleRequest = async (
 ) => {
 	const { pathname, search } = new URL(request.url);
 
-	const decodedPathname = decodePath(pathname);
+	let decodedPathname = decodePath(pathname);
+	// normalize the path
+	decodedPathname = decodedPathname.replaceAll('//', '/');
+
 	const intent = await getIntent(decodedPathname, configuration, exists);
 
 	if (!intent) {
@@ -42,6 +45,8 @@ export const handleRequest = async (
 	 * We combine this with other redirects (e.g. for html_handling) to avoid multiple redirects.
 	 */
 	if (encodedDestination !== pathname || intent.redirect) {
+		console.log(encodedDestination, pathname);
+
 		return new TemporaryRedirectResponse(encodedDestination + search);
 	}
 
@@ -638,6 +643,8 @@ const safeRedirect = async (
 		return null;
 	}
 
+	console.log(file, destination, configuration);
+
 	if (!(await exists(destination))) {
 		const intent = await getIntent(destination, configuration, exists, true);
 		// return only if the eTag matches - i.e. not the 404 case

packages/workers-shared/asset-worker/tests/handler.test.ts

@@ -96,4 +96,37 @@ describe("[Asset Worker] `handleRequest`", () => {
 
 		expect(response.status).toBe(200);
 	});
+
+	it("normalizes double slashes", async () => {
+		const configuration: Required<AssetConfig> = {
+			html_handling: "none",
+			not_found_handling: "none",
+		};
+		const eTag = "some-etag";
+		const exists = vi.fn().mockReturnValue(eTag);
+		const getByETag = vi.fn().mockReturnValue({
+			readableStream: new ReadableStream(),
+			contentType: "text/html",
+		});
+
+		let response = await handleRequest(
+			new Request("https://example.com/abc/def//123/456"),
+			configuration,
+			exists,
+			getByETag
+		);
+
+		expect(response.status).toBe(307);
+		expect(response.headers.get('location')).toBe('/abc/def/123/456');
+
+		response = await handleRequest(
+			new Request("https://example.com/%2fexample.com/"),
+			configuration,
+			exists,
+			getByETag
+		);
+
+		expect(response.status).toBe(307);
+		expect(response.headers.get('location')).toBe('/example.com/');
+	});
 });