7.6.1 breaks typegen for params when using fs-routes

[GardSteinsvik]

I'm using React Router as a...

framework

Reproduction

1. Go to https://stackblitz.com/edit/github-ovu8zgq7?file=app%2Froutes%2Fparams.%24test.tsx
2. Wait for npm install && npm run dev
3. Observe that 'params.test' is possibly 'undefined' on line 4

System Info

System:
    OS: macOS 15.4.1
    CPU: (10) arm64 Apple M1 Max
    Memory: 86.69 MB / 32.00 GB
    Shell: 3.7.1 - /opt/homebrew/bin/fish
  Binaries:
    Node: 20.18.1 - ~/.nvm/versions/node/v20.18.1/bin/node
    npm: 10.8.2 - ~/.nvm/versions/node/v20.18.1/bin/npm
    pnpm: 10.6.5 - ~/Library/pnpm/pnpm
    bun: 1.2.13 - ~/.bun/bin/bun
  Browsers:
    Chrome: 136.0.7103.114
    Safari: 18.4
  npmPackages:
    @react-router/dev: 7.6.1 => 7.6.1 
    @react-router/express: 7.6.1 => 7.6.1 
    @react-router/fs-routes: 7.6.1 => 7.6.1 
    @react-router/node: 7.6.1 => 7.6.1 
    @react-router/serve: 7.6.1 => 7.6.1 
    react-router: 7.6.1 => 7.6.1 
    vite: 6.3.5 => 6.3.5

Used Package Manager

npm

Expected Behavior

Route.LoaderArgs should identify that $test is a required param so that test is a key in params and that params.test is a string.
This worked fine in version 7.6.0.

Actual Behavior

Route.LoaderArgs does not identify $test as a param, and test is not an identified key in params by TypeScript. params.test is inferred as string | undefined.

[timdorr]

I think this is related to #13574

[pcattori]

This looks to be a limitation of StackBlitz and how it handles dot files.

If I insist that StackBlitz looks at this file by opening it in the StackBlitz terminal with:

code .react-router/types/+routes.ts

then, it works as expected. I also verified that this works as expected when reproducing this issue locally.

Still useful to know about this limitation, so thanks for filing the issue! But since this is fundamentally not a React Router issue but a StackBlitz limitation, an issue should be created in their project.

[GardSteinsvik]

@pcattori This is issue is not a StackBlitz limitation. The provided screenshots clearly shows that this happens outside of StackBlitz.
This issue blocks keeping my application's dependencies up to date. Please reopen the issue.

[pcattori]

I've tried reproducing here https://github.com/pcattori/repro-13695 by copying each file from your StackBlitz link individually (including package-lock.json) and I am unable to reproduce the issue anywhere outside of StackBlitz.

npm run typecheck runs without any errors and both VSCode and Neovim don't show any diagnostic errors from the LSP. The only way I've been able to see your issue is within StackBlitz and that environment is known to have some issues with dot files.

Could you share a reproduction outside of StackBlitz? That would help me diagnose the issue

npm run typecheck:

VSCode:

Neovim:

[GardSteinsvik]

Thank you for taking the time to investigate it further, @pcattori!

When I tried to reproduce it I discovered that I was missing ".react-router/types/**/*" in "include" in my tsconfig.json, and the jump from 7.6.0 to 7.6.1 seems to not like that 😅
I did however have a "**/*.ts" which I believed would have included the relevant files, but it seems that TypeScript have not configured their ** glob to include segments starting with a .!

I now agree that we can keep this issue closed 😎 Thanks again!

[Ryan-Maughan]

Thanks @GardSteinsvik & @pcattori.

I have been watching this with interest as I had the same issue.
Interesting how this worked before 7.6.1 but adding ".react-router/types/**/*" to "include" also fixed it for me.

[nightridefm]

Hmm, I've noticed that 7.6.1+ has broken typegen on params for me in a Deno environment. Working fine on 7.6.0
I don't have a tsconfig.json as ts settings are configured inside the deno.json file.
I'm setting up routes with a root RouteConfig routes.ts

[pcattori]

Hmm, I've noticed that 7.6.1+ has broken typegen on params for me in a Deno environment. Working fine on 7.6.0 I don't have a tsconfig.json as ts settings are configured inside the deno.json file. I'm setting up routes with a root RouteConfig routes.ts

Could you share a reproduction?

[nightridefm]

@pcattori I believe I've reproduced it here, in a node environment, so its not just in deno.
https://stackblitz.com/edit/github-ovu8zgq7-7pc4v2qf?file=app%2Froutes%2Fchild.tsx
Params are only typed as {[x: string]: string | undefined}

This is with params on a clientLoader with ssr: false with unstable_middleware enabled

[pcattori]

@pcattori I believe I've reproduced it here, in a node environment, so its not just in deno. https://stackblitz.com/edit/github-ovu8zgq7-7pc4v2qf?file=app%2Froutes%2Fchild.tsx Params are only typed as {[x: string]: string | undefined}

This is with params on a clientLoader with ssr: false with unstable_middleware enabled

This looks to be the same StackBlitz issue I mentioned earlier. If I force StackBlitz to acknowledge .react-router/types/+routes.ts by opening it, then params is typed correctly.

[nightridefm]

@pcattori just an FYI that I found my issue. I had the vite-tsconfig-paths plugin in my vite config, this was breaking the type inference on params.