The github.com/luxfi/node/errors package shipped with zero tests despite
being a public utility surface (sentinel errors, WrappedError context
chain, Multi/Join aggregation, retry helpers). This adds 22 tests covering:
- WrappedError.Error format (with and without message)
- Wrap/WrapWithContext nil pass-through and context preservation
- errors.Is / errors.As chain through Wrap (incl. double-wrap)
- IsNotFound, IsClosed, IsTimeout helpers
- IsTemporary against both sentinel errors and the Temporary() interface
- IsPermanent across all permanent sentinels + fmt.Errorf %w chains
- GetCategory: wrapped category, sentinel inference, unknown fallback,
and the precedence rule (wrapped category beats inferred category)
- Multi.Error/Add/Err for 0, 1, and N errors; nil-add ignored
- Join nil pass-through and multi-error combination
Result: 100.0% statement coverage, race-clean.
Abhishek Krishna