Summary

Documentation-only corrections to action.yml: two optional inputs now carry explicit default values, and the cache-hit output description is replaced with a precise account of its three observable states.

Changes

• inputs.restore-keys — added default: ''; the implementation's getInputAsArray returns an empty list when the input is absent, so '' accurately reflects the runtime behaviour
• inputs.upload-chunk-size — added default: ''; getInputAsInt returns undefined on empty input, passing uploadChunkSize: undefined to cache.saveCache and deferring to the @actions/cache library's own chunk-size
  default
• outputs.cache-hit description — expanded from a vague one-liner to document all states:
  • 'true' — exact primary key match
  • 'false' — partial match via a restore-key, or cache service unavailable
  • not emitted — when no cache entry is found at all (intentional behaviour preserved from #1466)

Description

Motivation and Context

• restore-keys and upload-chunk-size were the only two optional inputs without a default property, creating an inconsistency across the file and leaving tooling (IDE YAML hints, schema validators) unable to show callers what happens when the input is omitted.
• The original cache-hit description implied the output is always a boolean, which is incorrect. The "not set on cache miss" edge case is a known quirk that causes subtle bugs when downstream steps test cache-hit == 'false' to detect a miss — documenting it inline makes it visible without requiring users to read source code or issue history.

Impact

• No behaviour change — all three modifications are documentation only; no runtime logic is touched.
• Backward compatible — adding default: '' to string inputs does not change what the action receives when the input is omitted by a caller.
• IDE tooltips, auto-generated docs, and YAML schema tooling that reads action.yml metadata will now surface accurate information.

How Has This Been Tested?

• Verified restore-keys handling against getInputAsArray in src/utils/actionUtils.ts (splits on newlines, filters empty strings → [] when input is absent).
• Verified upload-chunk-size handling against getInputAsInt in src/utils/actionUtils.ts (parseInt('') → NaN → returns undefined).
• Verified cache-hit states against restoreImpl.ts: core.setOutput(Outputs.CacheHit, "false") on unavailable service, no setOutput call inside the !cacheKey branch (comment references Cache-Hit set to string, not boolean, as of v4.1.0 #1466), and core.setOutput(Outputs.CacheHit, isExactKeyMatch.toString()) on successful restore.
• No functional code changed; no test run required.

Screenshots (if appropriate): NA

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (add or update README or docs)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.