Ensure latest canary of Next.js is installed in repros

[karlhorky]

What?

Always use latest canary in reproduction templates

Why?

Following up with the new PR #64967, it appears that CodeSandbox caches package.json and the changes made to it from pnpm update next - which uses an outdated canary version of Next.js

Eg. currently, the reproduction template URL uses next@14.3.0-canary.26 is not the latest canary

https://codesandbox.io/p/sandbox/github/vercel/next.js/tree/canary/examples/reproduction-template

How?

Switch CodeSandbox "dev" task to update the pinned canary version of Next.js in the cached package.json to the latest Next.js canary:

• old: pnpm update next
• new: pnpm update next@canary

$ pnpm update next@canary
Packages: +4 -4
++++----
Progress: resolved 65, reused 43, downloaded 0, added 0, done

dependencies:
- next 14.3.0-canary.26
+ next 14.3.0-canary.32

Done in 2.9s

This will:

A) upgrade the pinned version in the cached package.json file
B) perform this upgrade on forking of the sandbox (because of restartOn.clone = true)

Caveats

Users restarting the dev task for any reason will get the (potentially unwanted) side effect of upgrading Next.js to the latest canary:

1.⁠ User creates a reproduction on a certain canary version
2.⁠ ⁠⁠New canary version is released
3.⁠ ⁠⁠User restarts the dev task for any reason
4.⁠ ⁠⁠Next.js version updated, potentially leading to the bug disappearing from the reproduction (URL may be published somewhere publicly) 💥

This could be seen as unexpected behavior / a "paper cut".

However, it seems like the tradeoff is worth it, as having the latest canary on all new reproductions is higher value than allowing the potential (less common) action of restarting the dev task in a devbox.

In future, I would however like to explore solutions with CodeSandbox that will allow for restarting the dev server without this unwanted side effect, eg. potentially with an environment variable or something similar.

cc @styfle

[ijjk]

Allow CI Workflow Run

• approve CI run for commit: cd842b6

Note: this should only be enabled once the PR is ready to go and can only be enabled by a maintainer

[karlhorky]

@balazsorban44 thanks for the review and merge! 🙌

I'll check back once a new canary after 14.3.0-canary.32 is published, hopefully at that time, navigating to the link below and then forking will lead to the latest version being installed:

• https://codesandbox.io/p/sandbox/github/vercel/next.js/tree/canary/examples/reproduction-template?file=%2Fpackage.json

[karlhorky]

Confirmed, the pnpm update next@canary command automatically updates to the latest canary on fork of the reproduction sandbox above (next@14.3.0-canary.33 installed after update command):