Merge pull request #1239 from Shelf-nu/adjust-url-shortener-middleware

adjustment: logic of handling redirects for url shortener

app/components/zxing-scanner.tsx

@@ -32,6 +32,7 @@ export const ZXingScanner = ({
        * - ^(https?:\/\/[^\/]+\/ matches the protocol, domain, and the initial slash.
        * - (?:qr\/)? optionally matches the /qr/ part.
        * - ([a-zA-Z0-9]+))$ matches the QR ID which is the last segment of the URL.
+       * - $ ensures that there are no additional parts after the QR ID.
        */
       // Regex to match both old and new QR code structures
       const regex = /^(https?:\/\/[^/]+\/(?:qr\/)?([a-zA-Z0-9]+))$/;

app/utils/id/index.ts

@@ -10,20 +10,14 @@ export function isQrId(id: string): boolean {
   const possibleLengths = [DEFAULT_CUID_LENGTH, LEGACY_CUID_LENGTH];
   const length = id.length;
 
-  // @TODO - temporary disabled number check due to bug and corrupted ids
-  // /**
-  //  * 1. The string must contain only lowercase letters and digits.
-  //  * 2. The string must start with a lowercase letter.
-  //  * 3. The string must contain at least one digit.
-  //  */
-  // const regex = /^(?=.*\d)[a-z][0-9a-z]*$/;
-
   /**
-   * Adjusted criteria:
-   * 1. The string must contain only lowercase letters.
-   * 2. The string must start with a lowercase letter.
+   * The following conditions need to be met for the middleware to redirect to a QR code. In the rest of the cases, it just redirects to app root.
+   * - The path should NOT include any special characters
+   * - The path should start with a small letter
+   * - The path should only have small letters and optional number
+   * - The path's length should fit within the allowed character lengths(10 for new and 25 for legacy QR codes)
    */
-  const regex = /^[a-z][0-9a-z]*$/;
+  const regex = /^[a-z][a-z0-9]*$/;
 
   // Validate the ID against the criteria
   if (

docs/url-shortener.md

@@ -6,8 +6,19 @@
 The url shortener functionality allows you to make your QR codes hold less data, thus making them more readable.
 The redirection is handled via the `urlShortener` middleware.
 
+## How to use it?
+
 Using the shortener is super easy.
 
 1. Add an env variable with your shortner domain: `URL_SHORTENER="eam.sh"`. You can refer to `.env.example` for further example. The domain should not include the protocol (http/https) or a trailing slash
 2. Make sure you point your short domain to your application server
 3. Enjoy
+
+## How does it work?
+
+1. When a request is received starting with the shortened url, it gets handled by the `urlShortener` middleware
+2. The following conditions need to be met for the middleware to redirect to a QR code. In the rest of the cases, it just redirects to app root.
+   - The path should NOT include any special characters
+   - The path should start with a small letter
+   - The path should only have small letters and optional number
+   - The path's length should fit within the allowed character lengths(10 for new and 25 for legacy QR codes)

server/middleware.ts

@@ -142,6 +142,7 @@ export function cache(seconds: number) {
 export function urlShortener({ excludePaths }: { excludePaths: string[] }) {
   return createMiddleware(async (c, next) => {
     const fullPath = c.req.path;
+
     // Remove the URL_SHORTENER part from the beginning of the path
     const pathWithoutShortener = fullPath.replace(
       `/${process.env.URL_SHORTENER}`,
@@ -171,9 +172,11 @@ export function urlShortener({ excludePaths }: { excludePaths: string[] }) {
       return c.redirect(safeRedirect(redirectUrl), 301);
     }
 
-    // Handle all other cases
-    const redirectUrl = `${serverUrl}${pathname}`;
-    // console.log(`urlShortener middleware: Redirecting to ${redirectUrl}`);
-    return c.redirect(safeRedirect(redirectUrl), 301);
+    // console.log(`urlShortener middleware: Redirecting to ${serverUrl}`);
+    /**
+     * In all other cases, we just redirect to the app root.
+     * The URL shortener should only be used for QR codes
+     * */
+    return c.redirect(safeRedirect(serverUrl), 301);
   });
 }