[progress][meter] De-duplicate formatValue function

[sai6855]

I was going through this issue #3688 and this comment #3709 (comment), changes in this PR reduced size by 68B without hurting readability. Felt it as quick win

[pkg-pr-new]

• vite-css-base-ui-example

  pnpm add https://pkg.pr.new/mui/base-ui/@base-ui/react@3805
  

  pnpm add https://pkg.pr.new/mui/base-ui/@base-ui/utils@3805
  

commit: 3cf9672

[mui-bot]

Bundle size report

Bundle	Parsed size	Gzip size
@base-ui/react	▼-68B(-0.02%)	▼-24B(-0.02%)

Details of bundle changes

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[Copilot]

Pull request overview

This PR de-duplicates the formatValue function that was identically implemented in both the Progress and Meter components by extracting it to a shared utility module. This refactoring reduces bundle size by 68 bytes without affecting functionality or readability, supporting the ongoing effort to optimize Base UI's bundle size (issue #3688).

Changes:

• Extracted the formatValue function to utils/formatNumber.ts as a shared utility
• Updated ProgressRoot and MeterRoot to import the shared function instead of maintaining local copies

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
packages/react/src/utils/formatNumber.ts	Added the shared formatValue function that handles value formatting with optional locale and format options
packages/react/src/progress/root/ProgressRoot.tsx	Removed local formatValue function and imported the shared version from utils
packages/react/src/meter/root/MeterRoot.tsx	Removed local formatValue function and imported the shared version from utils

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[greptile-apps]

Greptile Summary

Deduplicates the formatValue function from MeterRoot and ProgressRoot components by moving it to the shared utils/formatNumber.ts module, achieving a 68B bundle size reduction.

• The original implementations in both components were nearly identical, differing only in the first parameter's type (number in MeterRoot vs number | null in ProgressRoot)
• The new shared implementation uses number | null to accommodate both use cases
• Type safety is maintained since MeterRoot's value prop is typed as number (non-nullable), preventing null values from being passed
• The change aligns with the goal of reducing Base UI's bundle size to be more competitive with Radix (currently 20KB larger)

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• The refactoring is straightforward and maintains backward compatibility. The shared implementation is identical to ProgressRoot's original version and handles both nullable and non-nullable values correctly. Type safety ensures MeterRoot will never pass null values despite the function accepting them.
• No files require special attention

Important Files Changed

Filename	Overview
packages/react/src/utils/formatNumber.ts	Added shared formatValue function to deduplicate identical logic from MeterRoot and ProgressRoot
packages/react/src/meter/root/MeterRoot.tsx	Removed local formatValue function and imported the shared utility from formatNumber.ts
packages/react/src/progress/root/ProgressRoot.tsx	Removed local formatValue function and imported the shared utility from formatNumber.ts

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[LukasTy]

Nice optimization. 👍

[LukasTy]

Nitpick: Given that this is now a more global util, I feel like formatNumberValue might be a more precise name for it. 🤔
WDYT?

[sai6855]

Yes, makes sense. I'll update and merge

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