tags:

Wrap and Unwrap Errors in Go

Wrap errors with fmt.Errorf %w and inspect with errors.Is / As.

Author: chris

// Language: Go

package main

import (
    "errors"
    "fmt"
    "os"
)

func loadConfig(path string) error {
    if _, err := os.Stat(path); err != nil {
        return fmt.Errorf("loadConfig %q: %w", path, err)
    }
    return nil
}

func main() {
    err := loadConfig("/no/such/file")
    if errors.Is(err, os.ErrNotExist) {
        fmt.Println("config missing:", err)
    }
}