Golang Error Handling Standards
Priority: P0 (CRITICAL)
Principles
- Errors Values: Handle them like any other value.
- Handle Once: Log OR Return. Never Log AND Return (creates duplicate logs).
- Add Context: Don't return
err bubble up. Wrap it with context: fmt.Errorf("failed to open file: %w", err).
- Use Standard Lib: Go 1.13+
errors package (Is, As, Unwrap) sufficient. Avoid pkg/errors (deprecated).
Guidelines
- Sentinel Errors: Expoted, fixed errors (
io.EOF, sql.ErrNoRows). Use errors.Is(err, io.EOF).
- Error Types: Structs implementing
error. Use errors.As(err, &target).
- Panic: Only for unrecoverable startup errors.
Anti-Patterns
- No bare return err: Wrap with
fmt.Errorf("context: %w", err) to preserve call chain.
- No string error checks: Use
errors.Is/errors.As; string comparison brittle.
- No swallowed errors: Never assign errors to
_; always handle or propagate.
References
