Middleware is interfering with `shouldRevalidate`

[DiederikvandenB]

Reproduction

https://stackblitz.com/edit/github-g8dxfe6q-pglgvmkd?file=react-router.config.ts

Changing the value of unstable_middleware to true results in the parent-loader to always fire. When middleware is disabled, it only fires on the initial page load.

System Info

System:
    OS: macOS 15.6.1
    CPU: (14) arm64 Apple M3 Max
    Memory: 404.39 MB / 36.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 24.4.0 - /opt/homebrew/bin/node
    npm: 11.4.2 - /opt/homebrew/bin/npm
    pnpm: 10.6.2 - /opt/homebrew/bin/pnpm
  Browsers:
    Chrome: 139.0.7258.139
    Edge: 139.0.3405.119
    Safari: 18.6
  npmPackages:
    @react-router/dev: ^7.8.2 => 7.8.2 
    @react-router/node: ^7.8.2 => 7.8.2 
    @react-router/serve: ^7.8.2 => 7.8.2 
    react-router: ^7.8.2 => 7.8.2 
    vite: ^6.3.3 => 6.3.5

Used Package Manager

pnpm

Expected Behavior

Clicking the "Go to next child" link should not trigger a revalidation of the parent-loader

Actual Behavior

The parent-loader is being revalidated, as can be seen in the terminal console.logs

Important: this behavior only occurs when unstable_middleware is set to true in react-router.config.ts

[semet]

i notice this weird behaviour shift in v7.8.2 specific. I was having hard time debugging what the heck is wrong. I have shouldRevalidate logic in my root.tsx that only returns true if some condition meet. The loader in root.tsx is set not to run on every child route navigation and only run on initial load and in some specific condition i set in shouldRevalidate logic. But in v7.8.2, this break and it ignores shouldRevalidate even though we entirely return false there. When i revert to v7.8.1, it is solved.

here is my shouldRevalidate logic

export const shouldRevalidate = ({
  actionResult,
  defaultShouldRevalidate,
}: ShouldRevalidateFunctionArgs) => {
  if (actionResult && actionResult.success) {
    return defaultShouldRevalidate
  }
  return false
}

the bug applies even if we make it like this export const shouldRevalidate = () => false

the loader will keeps firing as of v7.8.2

[DiederikvandenB]

Do you have middleware enabled too @semet ?

[semet]

Do you have middleware enabled too @semet ?

yes. I notice this behavior only in v7.8.2

in v7.8.1, this is not happening.

[semet]

Do you have middleware enabled too @semet ?

in the stackblitz you provide, just change all the "^7.7.1" into exact 7.8.1 (or bellow), and it will solve the issue...

[rossipedia]

I think I have a root cause. Testing out a patch at the moment, if it pans out I will have a PR shortly.

[joseph0926]

@semet

You mentioned that everything worked normally up to version 7.8.1, but issues started appearing from 7.8.2 onward. I examined all the differences between the two versions,
and in my opinion, it seems the issue was caused by the omission of passing skipRevalidation.

PR: #14286

[rossipedia]

lol we landed on roughly the same solution (#14287), I'll close mine in favor of yours 👍

[joseph0926]

@rossipedia

Wow, thank you so much.
I had a really hard time reproducing this bug issue for testing compared to other things.
I wasn't sure if my solution was correct, but since it's similar to yours, I feel reassured.

Thanks again.

(But my solution might be wrong, lol;;,,)

[semet]

@rossipedia

Wow, thank you so much. I had a really hard time reproducing this bug issue for testing compared to other things. I wasn't sure if my solution was correct, but since it's similar to yours, I feel reassured.

Thanks again.

(But my solution might be wrong, lol;;,,)

im so glad that @DiederikvandenB reproduce it in a dead simple way.