golang-error-handling SKILL.md skillA

golang-error-handling from codeready-toolchain/tarsy is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

mdr add codeready-toolchain/tarsy/golang-error-handling@git:20260304.7bde6ac

Pins git:20260304.7bde6ac in mdr.lock. Pin the fingerprint instead.

Audit grade

A, 17 of 17 checks passed

Kind

SKILL.md skill

Repository

codeready-toolchain/tarsy

Path

.cursor/skills/golang-error-handling/SKILL.md

Versions recorded

2

Latest version

git:20260304.7bde6ac, committed Mar 4, 2026

First version recorded

Feb 5, 2026

Size

10,921 bytes

Repository stars

10

License

Apache-2.0

Error handling patterns for Go including error wrapping, custom errors, sentinel errors, and error checking best practices. Use when implementing error handling, defining error types, or working with error flows.

Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.

What the file says

# Go Error Handling

Modern error handling patterns for Go following 2025-2026 best practices.

## Basic Error Handling

**Always check errors:**
```go
result, err := doSomething()
if err != nil {
	return fmt.Errorf("operation failed: %w", err)
}
```

**Never ignore errors (unless explicitly documented):**
```go
// Bad
doSomething()

// Good - explicit discard when safe
_ = file.Close()

// Good - handle in defer with function
defer func() {
	if err := file.Close(); err != nil {
		log.Printf("failed to close file: %v", err)
	}
}()
```

## Error Wrapping

**Use `%w` to wrap errors:**
```go
func GetUser(id string) (*User, error) {
	user, err := db.Query(id)
	if err != nil {
		return nil, fmt.Errorf("failed to get user %s: %w", id, err)
	}
	return user, nil
}
```

**Unwrap errors with `errors.Is()` and `errors.As()`:**
```go
err := GetUser("123")
if errors.Is(err, sql.ErrNoRows) {
	// Handle not found
}

var validationErr *ValidationError
if errors.As(err, &validationErr) {
	// Handle validation error
	fmt.Printf("field: %s, message: %s", validationErr.Field, validationErr.Message)
}
```

## Sentinel Errors

**Define package-level error values:**
```go
package services
…

Read the whole file at its exact version.

How to install

mdr add codeready-toolchain/tarsy/golang-error-handling@sha256:37a19a37092e62ce

[![mdr](https://markdownregistry.com/badge/art_ru67wosipgtpb6c4.svg)](https://markdownregistry.com/a/art_ru67wosipgtpb6c4)

Versions

The registry has recorded 2 versions of this file, between Feb 5, 2026 and Mar 4, 2026, about one every 28 days.

Audit of the latest version

Source

API

GET https://markdownregistry.com/api/v1/artifacts/art_ru67wosipgtpb6c4
GET https://markdownregistry.com/api/v1/resolve?ref=codeready-toolchain/tarsy/golang-error-handling
GET https://markdownregistry.com/api/v1/blob/37a19a37092e62cec5e03d62eb6d1c1838fa89be60131b814d65ed7eb7c28ea9

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