refactor(fileSize): rename showDiff to diff

[chenjiahan]

Summary

• Simplify the file size diff configuration by using a shorter name.
• Remove unused diff-related header calculations to clean up the code.

Related Links

• feat(core): add showDiff option to printFileSize  #6635 (review)

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

[netlify]

✅ Deploy Preview for rsbuild ready!

Name	Link
🔨 Latest commit	7360a6d
🔍 Latest deploy log	https://app.netlify.com/projects/rsbuild/deploys/6930011b9364080008c8c3d2
😎 Deploy Preview	https://deploy-preview-6688--rsbuild.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.
Lighthouse	1 paths audited Performance: 67 (🟢 up 5 from production) Accessibility: 100 (no change from production) Best Practices: 100 (no change from production) SEO: 100 (no change from production) PWA: 60 (no change from production) View the detailed breakdown and full score reports

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[Copilot]

Pull request overview

This PR refactors the file size diff configuration by renaming showDiff to diff for a more concise API, and removes unused diff-related header calculation code.

Key changes:

• Renamed printFileSize.showDiff to printFileSize.diff across type definitions, implementation, and documentation
• Removed unused maxDiffLength and showDiffHeader parameters from getHeader() function
• Added version history section documenting the diff option addition in v1.6.13

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
website/docs/en/config/performance/print-file-size.mdx	Updated type definition, section heading, usage examples, and added version history for the renamed diff option
packages/core/src/types/config.ts	Renamed showDiff property to diff in PrintFileSizeOptions type
packages/core/src/plugins/fileSize.ts	Updated property references from showDiff to diff, removed unused diff header parameters and logic from getHeader() function

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.