Requestly Desktop App Bug: Incorrect Route Matching

Introduction

In this article, we will dive into a peculiar bug encountered in the Requestly Desktop App, specifically within the BrowserStack-powered version. The problem arises when creating collections containing multiple routes, such as GET /, POST /, PATCH /, and GET /:id. The core issue is that triggering any non-create endpoint (e.g., PATCH / or GET /:id) inadvertently causes the create (POST /) handler to run as well. This behavior is unexpected and can lead to significant confusion and errors in development and testing environments. This article aims to describe the issue, explore possible causes, suggest a fix, and provide detailed steps to reproduce the bug, ensuring that developers and users of Requestly are well-informed and can effectively address this problem.

Describe the Issue

When working with the Requestly Desktop App, creating a collection with multiple routes intended for distinct HTTP methods and endpoints should result in each route being handled independently. However, a bug exists where triggering any route other than POST /, such as PATCH / or GET /:id, unexpectedly also triggers the POST / route. This means that a request intended to update a record (PATCH) or fetch a record by ID (GET) inadvertently creates a new record via the POST / route. This unexpected behavior can lead to data duplication, incorrect updates, and overall instability in the application being tested or developed. This is particularly problematic in environments where precise control over API behavior is crucial.

Possible Cause

The most likely cause of this issue is that the route matching logic within Requestly Desktop App might not be strictly checking the HTTP method. Instead, it may be primarily matching routes based on the path alone. For instance, if a request is made to /, the matching algorithm might find both the GET / and POST / routes and, due to the lack of strict method validation, trigger both handlers. This would explain why non-POST requests inadvertently trigger the POST / route. Another possible cause could be related to how Requestly handles route priorities or middleware within collections, but the primary suspect is the insufficient validation of the HTTP method during route matching. Ensuring that both the path and the HTTP method are validated is crucial for correct route handling.

Suggested Fix

To address this bug, the route matching function within Requestly Desktop App must be updated to ensure strict validation of both the HTTP method and the path. The matching logic should resemble the following pseudo-code:

function matchRoute(requestMethod, requestPath, routeMethod, routePath) {
  return requestMethod === routeMethod && requestPath === routePath;
}

This fix ensures that a route is only triggered if both the HTTP method and the path match the incoming request. By implementing this strict validation, the unintended triggering of the POST / route when other endpoints are accessed can be prevented. Additionally, it's important to review the route prioritization and middleware handling within Requestly to ensure no conflicting logic contributes to this issue. Thorough testing after implementing this fix is crucial to verify that the bug is resolved and that all routes behave as expected.

Repro Steps

To reproduce this issue, follow these detailed steps:

1. Open the Requestly Desktop App (BrowserStack powered) on a Windows machine.
2. Create a New Collection: In the app, create a new collection to house your routes.
3. Add Multiple Routes: Inside the newly created collection, add the following routes:
   • POST / → Simulate creating a record.
   • GET / → Simulate fetching all records.
   • PATCH / → Simulate updating a record.
   • GET /:id → Simulate fetching a record by ID.
4. Click Save: Ensure that all routes are saved within the collection.
5. Send a Request: Use a tool like Postman or the built-in request tool in Requestly to send a request to any route other than POST /. For example, send a PATCH / request or a GET /:id request.
6. Observe the Behavior: Monitor the backend logs or the Requestly request/response panel to see which routes are triggered. You should observe that the POST / route is also triggered, even though it should not be.

By following these steps, you can reliably reproduce the bug and confirm that the POST / handler is being triggered unexpectedly. This will help verify the issue and confirm that the suggested fix resolves the problem.

Expected Behavior

The expected behavior is that each route should be handled independently, matching both the path and the HTTP method. For example:

• PATCH / should only trigger its own handler, responsible for updating a record.
• GET /:id should only trigger the handler that fetches a record by ID.

Each route should execute its specific logic without inadvertently triggering other routes. This ensures that the API behaves predictably and that requests are handled correctly. Proper route handling is crucial for maintaining the integrity and reliability of the application.

Actual Behavior

The actual behavior observed is that when any non-POST endpoint is hit (e.g., PATCH /, GET /:id), the POST / handler is also triggered unexpectedly. This results in unintended side effects, such as the creation of new records when an update or fetch operation is performed. This deviation from the expected behavior indicates a flaw in the route matching logic, where the HTTP method is not being strictly validated, leading to incorrect route handling.

Additional Information

This behavior has been observed specifically in the Requestly Desktop App. When the same routes are tested in Postman, they work correctly, indicating that the issue is not with the API or backend logic itself. This suggests that the problem lies within Requestly's route handling or matching logic within collections. It’s also important to note that this issue occurs while working inside a team workspace. The backend stack being used is Node.js (Express), following a REST architecture with MongoDB. The controller logic and routing have been verified to be correct, further reinforcing that the issue is with Requestly’s route handling or matching logic in collections.

What Requestly Tool Were You Using?

• [x] Desktop-App

Your Environment

• Windows

Requestly Version

• v25.11.12

Error Screenshot

https://drive.google.com/file/d/1fRNFpqi332V3lCWJEOPXWXH-2loLbGTu/view?usp=drive_link

Conclusion

In conclusion, the bug in Requestly Desktop App where the POST / route is unexpectedly triggered when accessing other endpoints highlights a critical issue in route matching. The problem stems from a lack of strict validation of the HTTP method, leading to incorrect route handling. The suggested fix, which involves ensuring that both the path and the HTTP method are validated during route matching, should resolve this issue. By following the repro steps outlined in this article, developers can confirm the bug and verify the effectiveness of the fix. Addressing this bug is crucial for maintaining the reliability and predictability of API testing and development workflows within Requestly. Remember to consult MDN Web Docs for comprehensive information on HTTP methods and web protocols.