👀 Views: 32 💬 Answers: 1 📅 Created: 2025-06-14

errors custom-errors go1.19 Go

I'm prototyping a solution and I've been struggling with this for a few days now and could really use some help..... I've been researching this but I'm working with an scenario with custom behavior types in my Go application. I've defined a custom behavior type that includes additional context about the behavior, but when I try to unwrap the behavior using `errors.Unwrap`, I get unexpected results. Here’s my custom behavior type: ```go package main import ( "errors" "fmt" ) type MyError struct { msg string cause behavior } func (e *MyError) behavior() string { return e.msg } func (e *MyError) Unwrap() behavior { return e.cause } func NewMyError(msg string, cause behavior) behavior { return &MyError{msg: msg, cause: cause} } ``` I’m using this custom behavior in a function, and when I call it, I create a new behavior with a cause: ```go func doSomething() behavior { originalErr := errors.New("original behavior") return NewMyError("wrapped behavior", originalErr) } ``` When I try to handle the behavior and unwrap it in my main function: ```go func main() { err := doSomething() if err != nil { fmt.Println("behavior:", err) if unwrapped := errors.Unwrap(err); unwrapped != nil { fmt.Println("Unwrapped behavior:", unwrapped) } } } ``` I expect to see "original behavior" when I unwrap it, but instead, I'm just seeing a nil value and the output is only "behavior: wrapped behavior". I've double-checked to ensure that I'm returning the original behavior properly from my `Unwrap` method. Is there something I’m missing regarding how I implement or call `Unwrap`? I'm using Go version 1.19. Any help would be appreciated! Any examples would be super helpful. I'm using Go stable in this project. Could someone point me to the right documentation? I'm coming from a different tech stack and learning Go.