Unsetting search params in a URL with a hash fragment navigates to "/"

[developerdizzle]

Describe the bug

Given a URL with both search parameters and a hash fragment, unsetting the search params results in navigation to "/", losing any existing path/route.

The linked example does not actually run properly in the playground, but you can copy it to repro locally.

Your Example Website or App

https://playground.solidjs.com/developerdizzle/2f1f4876-fb97-4ce3-bede-d0e23e93b663

Steps to Reproduce the Bug or Issue

1. Navigate to a route with a querystring param and hash fragment, e.g.: /demo?foo=bar#test
2. Call setSearchParams({ foo: "" })
3. Notice the URL has changed to /#test

The bug does not happen if no hash fragment exists

Expected behavior

The existing route/path is maintained

Screenshots or Videos

solidjsrouterbug.mp4

Platform

• OS: Linux Mint
• Browser: Chrome
• Version: 150.0.7871.46

Additional context

No response

[ryansolid]

This is fixed in @solidjs/router@0.16.2 — the playground template pins an older 0.15.x.

What happened in 0.15.x: setSearchParams built its navigation target as mergeSearchString(search, params) + hash. When unsetting the only param the merged search string comes out empty, so the target became just #test. A target starting with # isn't recognized as query-relative, so it was resolved against the router base — landing you on /#test.

As of 0.16.2 the target is built as pathname + search + hash, so the path is always preserved. Verified with a regression test against your exact steps (/demo?foo=bar#test → setSearchParams({ foo: "" }) → stays on /demo#test).

Please upgrade and reopen if you still see it.