Cannot Pass Encoded URLs as Query Parameters

[okaufmann]

Hello guys,

I encountered a strange issue with how URLs containing encoded query parameters are processed in Inertia.js v2. Specifically, when passing an encoded URL as a query parameter, the resulting behavior seems inconsistent, especially when dots (.) are included in the parameter value. I wanted to ask if this could be a bug or if I might be doing something incorrectly.

Steps to Reproduce

Here’s a minimal example:

const testUrl = "https://example.com?redirect_url=https%3A%2F%2Fexample.com%2Fpath";

// Simulate URL processing (similar to how Inertia might handle it)
function simulateUrlProcessing(href) {
  const url = new URL(href); // Convert string to URL object
  const queryParams = new URLSearchParams(url.search); // Parse query params
  console.log("Parsed query parameters:", Object.fromEntries(queryParams.entries()));

  // Rebuild the URL
  const newQueryParams = new URLSearchParams(queryParams);
  const rebuiltUrl = `${url.origin}${url.pathname}?${newQueryParams.toString()}`;
  console.log("Rebuilt URL:", rebuiltUrl);

  return rebuiltUrl;
}

// Test with a problematic URL
simulateUrlProcessing(testUrl);

Observed Behavior

When the query parameter (redirect_url) contains encoded dots (.), slashes (/), and colons (:), the resulting URL sometimes:

1. Misinterprets the parameter as part of the path.
2. Incorrectly re-encodes the query string during processing.

For example, the input:

https://example.com?redirect_url=https%3A%2F%2Fexample.com%2Fpath

Results in:

https://example.com/%2Fpath

If dots (.) are replaced with another character, the output changes and behaves as expected:

https://example.com/?redirect_url=https%3A%2F%2Fexample.com%2Fpath

Questions

1. Could this be a newly introduced bug in Inertia.js v2?
2. Is there something wrong with how I am passing encoded URLs as query parameters?
3. Could this be related to how URL objects or query parameter encoding are handled internally?

I’d love any guidance on how to resolve this or confirm if this might be an issue.