fix(cache): log "caches is not defined" only once

[yuintei]

The log is repeated for every cache() call when globalThis.caches is not available. This PR ensures the message is logged only once.

$ vite

  VITE v8.0.0  ready in 675 ms

  ➜  Local:   http://localhost:5173/
  ➜  Network: use --host to expose
  ➜  press h + enter to show help
Cache Middleware is not enabled because caches is not defined.
Cache Middleware is not enabled because caches is not defined.
Cache Middleware is not enabled because caches is not defined.
Cache Middleware is not enabled because caches is not defined.
Cache Middleware is not enabled because caches is not defined.
Cache Middleware is not enabled because caches is not defined.
Cache Middleware is not enabled because caches is not defined.
Cache Middleware is not enabled because caches is not defined.
(repeats...)
Using vars defined in .env

The author should do the following, if applicable

• Add tests
• Run tests
• bun run format:fix && bun run lint:fix to format the code
• Add TSDoc/JSDoc to document the code (N/A)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.89%. Comparing base (1aa32fb) to head (66b2c61).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4871   +/-   ##
=======================================
  Coverage   92.89%   92.89%           
=======================================
  Files         177      177           
  Lines       11797    11801    +4     
  Branches     3515     3514    -1     
=======================================
+ Hits        10959    10963    +4     
  Misses        837      837           
  Partials        1        1           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[yusukebe]

Hi @yuintei

This PR is not bad. BUT, the cache function is called only once in the initialization phase, so usually the log shows only one. So, in your environment, showing the log multiple times may be a little weird. Can you share the minimal project to reproduce it?

[yuintei]

Hi @yusukebe, thanks for the review. Here's a minimal reproduction: Link

I use cache() on 20+ routes, so the log fills up the terminal on every dev server start, which is why I made this PR.

[yusukebe]

@yuintei

Thank you for the response and repro! I considered that declaring the variable with let and using it like globally is not a good design. I have another idea and will implement it later.