Agent-skills-standard golang-error-handling

Standards for error wrapping, checking, and definition in Golang. Use when wrapping errors, defining sentinel errors, or handling errors idiomatically in Go. (triggers: fmt.Errorf, errors.Is, errors.As, error wrapping, sentinel error, error handling)

install

source · Clone the upstream repo

git clone https://github.com/HoangNguyen0403/agent-skills-standard

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/HoangNguyen0403/agent-skills-standard "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/golang/golang-error-handling" ~/.claude/skills/hoangnguyen0403-agent-skills-standard-golang-error-handling && rm -rf "$T"

manifest: skills/golang/golang-error-handling/SKILL.md

source content

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

Error Wrapping Patterns