[jsweep] Clean allowed_extensions_helpers.cjs

[github-actions]

Summary

Expanded test coverage for allowed_extensions_helpers.cjs, a Node.js utility (no github-script context) that normalizes file extension allow-lists in workflow configurations.

The source file was already clean and modern (@ts-check, optional chaining, functional patterns). This sweep focused on bringing test coverage up to a comprehensive level.

Changes

allowed_extensions_helpers.test.cjs

Grew from 5 → 21 test cases across all three exported functions:

Function	Before	After
isGitHubExpression	2	7
normalizeAllowedExtension	2	7
parseAllowedExtensionsEnv	3	7

New edge cases covered:

• isGitHubExpression: surrounding whitespace trimming, expression with no inner spaces, empty string, plain extension, expression with trailing text
• normalizeAllowedExtension: empty string input, already-dotted extension, GitHub expression passthrough (unchanged), mixed-case extension
• parseAllowedExtensionsEnv: empty string returns null, single extension, expression-only input, blank values filtered from normalizedValues

Validation ✅

• Formatting: npm run format:cjs ✓
• Linting: npm run lint:cjs ✓
• Type checking: npm run typecheck ✓
• Tests: 21 passed ✓ (npx vitest run allowed_extensions_helpers)

Generated by jsweep - JavaScript Unbloater · ● 933.8K · ◷

• expires on Apr 28, 2026, 5:00 AM UTC

[Copilot]

Pull request overview

Expands unit test coverage for the allowed_extensions_helpers.cjs Node.js utility that detects GitHub Actions expressions and normalizes/parses extension allow-lists.

Changes:

• Added additional isGitHubExpression cases (whitespace handling, no-inner-space expressions, empty/plain strings, trailing text).
• Added additional normalizeAllowedExtension cases (empty input, already-dotted values, expression passthrough, mixed case).
• Added additional parseAllowedExtensionsEnv cases (empty string handling, single value parsing, expression-only inputs, filtering blanks post-normalization).

Show a summary per file

File	Description
actions/setup/js/allowed_extensions_helpers.test.cjs	Adds comprehensive edge-case coverage across the three exported helper functions.

Copilot's findings

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• Files reviewed: 1/1 changed files
• Comments generated: 0

[github-actions]

🧪 Test Quality Sentinel Report

Test Quality Score: 100/100

✅ Excellent test quality

Metric	Value
New/modified tests analyzed	14
✅ Design tests (behavioral contracts)	14 (100%)
⚠️ Implementation tests (low value)	0 (0%)
Tests with error/edge cases	14 (100%)
Duplicate test clusters	0
Test inflation detected	No
🚨 Coding-guideline violations	None

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Test Classification Details

View all 14 test classifications

Test	File	Classification	Notes
returns true for expression with surrounding whitespace	allowed_extensions_helpers.test.cjs	✅ Design	Edge case: whitespace tolerance
returns true for expression with no inner spaces	allowed_extensions_helpers.test.cjs	✅ Design	Edge case: compact expression format
returns false for plain extension	allowed_extensions_helpers.test.cjs	✅ Design	Boundary: non-expression input
returns false for empty string	allowed_extensions_helpers.test.cjs	✅ Design	Edge case: empty input
returns false for expression with trailing text	allowed_extensions_helpers.test.cjs	✅ Design	Boundary: partial match
returns empty string for empty input	allowed_extensions_helpers.test.cjs	✅ Design	Edge case: empty string
preserves existing leading dot and lowercases	allowed_extensions_helpers.test.cjs	✅ Design	Behavioral contract: case normalization
does not double-add dot when already present	allowed_extensions_helpers.test.cjs	✅ Design	Behavioral invariant: idempotent dot prefix
passes through GitHub expression unchanged	allowed_extensions_helpers.test.cjs	✅ Design	Behavioral contract: expression passthrough
handles mixed case extension without dot	allowed_extensions_helpers.test.cjs	✅ Design	Edge case: mixed case + dot insertion
returns null when env value is empty string	allowed_extensions_helpers.test.cjs	✅ Design	Edge case: empty env
parses single extension	allowed_extensions_helpers.test.cjs	✅ Design	Behavioral contract: minimal valid input
detects expression-only value	allowed_extensions_helpers.test.cjs	✅ Design	Behavioral contract: unresolved expression flag
filters out blank values after normalization	allowed_extensions_helpers.test.cjs	✅ Design	Edge case: whitespace-only entries filtered

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Flagged Tests — Requires Review

None. All 14 new tests are clean.

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Language Support

Tests analyzed:

• 🟨 JavaScript (*.test.cjs): 14 tests (vitest)

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Verdict

✅ Check passed. 0% of new tests are implementation tests (threshold: 30%). All 14 new tests verify observable behavioral contracts with good edge-case coverage across three functions (isGitHubExpression, normalizeAllowedExtension, parseAllowedExtensionsEnv).

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📖 Understanding Test Classifications

Design Tests (High Value) verify what the system does:

• Assert on observable outputs, return values, or state changes
• Cover error paths and boundary conditions
• Would catch a behavioral regression if deleted
• Remain valid even after internal refactoring

Implementation Tests (Low Value) verify how the system does it:

• Assert on internal function calls (mocking internals)
• Only test the happy path with typical inputs
• Break during legitimate refactoring even when behavior is correct
• Give false assurance: they pass even when the system is wrong

Goal: Shift toward tests that describe the system's behavioral contract — the promises it makes to its users and collaborators.

References: §24953920420

🧪 Test quality analysis by Test Quality Sentinel · ● 434K · ◷

[github-actions]

✅ Test Quality Sentinel: 100/100. Test quality is excellent — 0% of new tests are implementation tests (threshold: 30%). All 14 new tests cover behavioral contracts with strong edge-case coverage.