Updated readme with instructions

README.md

@@ -1,64 +1,46 @@
-# URL Shortener Take-Home Exercise (Fullstack)
-
-## Instructions
-
-Your task is to create a URL shortener web application (similar to [bitly](https://bitly.com/) or [TinyURL](https://tinyurl.com/)). This exercise is intentionally open-ended, and you are welcome to implement your solution using the language and tech stack of your choice. If you are familiar with React & Next.js, please use those for your submission. The core functionality of the application should be expressed through your own original code.
-
-You should aim to spend no more than 2 hours on this project. If you don't complete everything in 2 hours, please submit what you have - we value your time and want to see your prioritization skills.
-
-### Application Description
-
-At the root path (e.g., http://localhost:8080/), a user should be presented with a form that allows them to input a URL. When a user submits that form, it should convert the input URL to a shortened version and present that to the user.
-
-The shortened URL should be in the format: http://localhost:8080/{slug}, where `{slug}` is a unique identifier for the original URL.
-
-When a user navigates to the shortened URL, they should be redirected to the original URL that was used to generate this shortened URL.
-
-### Minimum Requirements
-
-* Format and method of generating slugs for shortened URLs are up to you
-* Shortened URLs do not need to persist across server shutdown/startup (i.e., setting up a DB isn't necessary - server memory should suffice)
-* Only allow valid http(s) URLs
-
-If you have additional time, consider spending it on testing or UI improvements as opposed to supplemental features.
-
-## Evaluation Criteria
-
-We will be evaluating your submission based on the following:
-
-1. Functionality: Does the application work as described?
-2. Code quality: Is the code clean, well-organized, and following best practices?
-3. Error handling: How does the application handle invalid inputs or errors?
-4. Technical choices: Are the chosen technologies appropriate for the task?
-5. Documentation: Is the code well-commented and the README clear?
-
-## Deliverables
-
-Please fill out the sections below in the _README.md_ of your project and submit according to the instructions you received with this project. Your code can be sent as a zip file or a link to a repository containing your project.
-
----
+# Url Shortener
 
 ## Implementation Details
 
-<!-- Provide a short description of your implementation (technologies used, brief overview of project architecture, etc.) -->
+I used Dart/Flutter to write the entire stack. Frontend is flutter compiled to web. Backend uses the [dart_frog](https://dartfrog.vgv.dev/) framework.
+
+Architecture is a simple server that serves the static frontend files on `/` and requests to create shortened urls as well as the redirects.
+
+Dart frog does file-based routing similar to Next.js. However, I was unable to get the static content served on `/` and get shortened urls to route to `/[slug]` so I added them to a sub-route `/u/[slug]`.
 
 ## How to Run
 
-<!--
-- Include instructions on how to run your implementation locally. Be sure to include any necessary setup steps, such as installing dependencies, as well as the commands to start the application.
--->
+### Running with Docker (Simpler)
+
+With docker installed, `cd` into the `new_backend/build/` directory where the `Dockerfile` is located. Build the docker image with
+
+```sh
+docker build -t <image_name> ./
+```
+
+Once built, run it with:
+```sh
+docker run -d -p 8080:8080 <image_name>
+```
+
+The container port is hard-coded, so you have to use the internal port 8080, the host can be whichever port.
+
+### Running the local dev server
+
+- [Install dart](https://dart.dev/get-dart)
+- [Install dart_frog](https://dartfrog.vgv.dev/docs/overview)
+
+Then run the backend with:
+```sh
+cd new_backend/ && dart pub get && dart_frog dev
+```
 
 ## Testing
 
-<!-- Describe how you tested your solution (automated testing, manual testing process, screenshots, etc.) -->
+I wrote some unit tests to get the url shortening to work, and everything else was tested manually. I also include some asserts in the code to verify the various assumptions I made in the code.
 
 ## Tools Used
 
-<!--
-- Describe any tools you used in developing your solution (e.g. ChatGPT for generating ideas and styles)
-- Note: The use of AI tools is not discouraged, but they should be used judiciously.
--->
+I used various documentation sites, like the one for the dart_frog web framework, as well as the [MDN docs for response codes](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status).
 
----
-
-Good luck, and we look forward to reviewing your submission!
+I discovered from asking an LLM that I could use the redirection status codes to do the url resolving, but otherwise referenced the docs to decide to use 308.

new_backend/lib/shrink_ray.dart

@@ -4,7 +4,7 @@ enum Status { ok, error }
 
 class ShrinkRay {
   static const shrinkLength = 6;
-  static const String shrinkChars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-._';
+  static const String shrinkChars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
 
   static ({Status status, String content}) shrinkUrl(String urlStr) {
     try {

new_backend/routes/index.dart

@@ -21,7 +21,6 @@ Future<Response> onRequest(RequestContext context) async {
         if (url == null) {
           return Response(statusCode: 401, body: 'Missing url');
         }
-        await Future<void>.delayed(const Duration(seconds: 2));
         final res = ShrinkRay.shrinkUrl(url);
         switch (res.status) {
           case Status.ok:
@@ -40,6 +39,13 @@ Future<Response> onRequest(RequestContext context) async {
         return Response(statusCode: 500, body: 'Unexpected error occurred');
       }
     case HttpMethod.get:
+      // final maybeUrl = shrunkUrls[urlPath];
+      // switch (maybeUrl) {
+      //   case null:
+      //     return Response(statusCode: 404);
+      //   default:
+      //     return Response(statusCode: 308, headers: {'Location': maybeUrl});
+      // }
       final file = File(path.join(Directory.current.path, 'public', 'index.html'));
       if (!file.existsSync()) {
         return Response(body: 'Index Not found');

new_backend/routes/u/[urlPath].dart

@@ -1,5 +1,3 @@
-import 'dart:convert';
-
 import 'package:dart_frog/dart_frog.dart';
 import 'package:new_backend/shrink_ray.dart';
 
@@ -18,7 +16,7 @@ Future<Response> onRequest(RequestContext context, String urlPath) async {
         case null:
           return Response(statusCode: 404);
         default:
-          return Response(statusCode: 302, headers: {'Location': maybeUrl});
+          return Response(statusCode: 308, headers: {'Location': maybeUrl});
       }
   }
 }

new_backend/test/routes/index_test.dart

@@ -8,14 +8,6 @@ class _MockRequestContext extends Mock implements RequestContext {}
 
 void main() {
   group('GET /', () {
-    test('responds with a 200 and "Welcome to Dart Frog!".', () {
-      // final context = _MockRequestContext();
-      // final response = route.onRequest(context);
-      // expect(response.statusCode, equals(HttpStatus.ok));
-      // expect(
-      //   response.body(),
-      //   completion(equals('Welcome to Dart Frog!')),
-      // );
-    });
+    test('responds with a 200 and "Welcome to Dart Frog!".', () {});
   });
 }