refactor(stringutil): extract isASCIIAlphanumeric helper in sanitize.go

[Copilot]

sanitize.go had two functions open-coding the identical ASCII alphanumeric rune test, creating divergence risk for the character-class definition.

Changes

• pkg/stringutil/sanitize.go — adds unexported helper isASCIIAlphanumeric(r rune) bool and replaces the duplicated inline expressions in SanitizeIdentifierName and SanitizeForFilename:

func isASCIIAlphanumeric(r rune) bool {
    return (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9')
}

// SanitizeIdentifierName
if isASCIIAlphanumeric(r) || r == '_' { ... }

// SanitizeForFilename
if isASCIIAlphanumeric(r) || r == '-' || r == '_' || r == '.' { ... }

Purely mechanical, behavior-preserving; existing tests cover both call sites.

• Fixes [refactor] stringutil: consolidate duplicated inline ASCII-alphanumeric rune checks #47446

[Copilot]

Pull request overview

Extracts a shared ASCII alphanumeric check to reduce duplicated sanitization logic without changing behavior.

Changes:

• Adds isASCIIAlphanumeric.
• Reuses it in both identifier and filename sanitizers.

Show a summary per file

File	Description
pkg/stringutil/sanitize.go	Consolidates duplicate character validation logic.

Review details

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• Files reviewed: 1/1 changed files
• Comments generated: 0
• Review effort level: Medium

[github-actions]

✅ Design Decision Gate 🏗️ completed the design decision gate check.

No ADR enforcement needed: PR #47455 does not have the 'implementation' label and has only 7 new lines of code in business logic directories (threshold: 100).

[github-actions]

✅ PR Code Quality Reviewer completed the code quality review.

[github-actions]

✅ Test Quality Sentinel completed test quality analysis.

No test files were added or modified in this PR. Test Quality Sentinel skipped.

[github-actions]

🧠 Matt Pocock Skills Reviewer has completed the skills-based review. ✅

[github-actions]

Clean refactor — the extracted isASCIIAlphanumeric helper correctly mirrors the original inline conditions and is applied consistently at both call sites. No logic changes, no issues found.

🧵 Reviewed using Impeccable skills by Impeccable Skills Reviewer · sonnet46 8.87 AIC · ⌖ 5.1 AIC · ⊞ 5K

[github-actions]

Clean refactor — approved

Extracting isASCIIAlphanumeric is a correct, behavior-preserving deduplication. Both call sites updated properly, helper is appropriately unexported, and existing tests cover both paths. No issues found.

🔎 Code quality review by PR Code Quality Reviewer · sonnet46 17.9 AIC · ⌖ 4.47 AIC · ⊞ 5.7K
_{Comment /review to run again}

[github-actions]

Skills-Based Review 🧠

Applied /codebase-design — the extraction is clean and behavior-preserving. ✅

📋 Key Themes & Highlights

Positive Highlights

• ✅ Single, clear definition of the ASCII alphanumeric character class — eliminates divergence risk
• ✅ Unexported helper keeps the interface surface minimal
• ✅ Both call sites are mechanically correct after the substitution
• ✅ Comment on the helper accurately describes its contract

Minor Observation

The helper isASCIIAlphanumeric is not directly unit-tested; it is exercised indirectly through SanitizeIdentifierName and SanitizeForFilename. That is acceptable for a small private helper, but a direct test would lock in the boundary conditions ('0', '9', 'a', 'z', 'A', 'Z', and one character outside each range) and make the contract self-documenting.

🧠 Reviewed using Matt Pocock's skills by Matt Pocock Skills Reviewer · sonnet46 17.4 AIC · ⌖ 4.54 AIC · ⊞ 6.7K
_{Comment /matt to run again}

[github-actions]

🎉 This pull request is included in a new release.

Release: v0.83.1