withstackcheck

withstackcheck checks error-returning statements are wrapped with errors.WithStack() only when the errors come from external packages.

⭕ Valid

func valid() error {
	var err error

	err = throw() // internal
	if err != nil {
		return err
	}

	_, err = json.Marshal(nil) // external
	if err != nil {
		return errors.WithStack(err)
	}

❌ Invalid

func invalid() error {
	var err error

	err = throw() // internal
	if err != nil {
		return errors.WithStack(err) // need to remove errors.WithStack()
	}

	_, err = json.Marshal(nil) // external
	if err != nil {
		return err // need to wrap with errors.WithStack()
	}

Why withstackcheck?

If we want to log an error and stack trace at the outer of the call stack, we need to memorize it at the package boundary.

Installation

go install github.com/codeout/withstackcheck/cmd/withstackcheck@latest

How to Use

go vet

go vet -vettool=$(go env GOPATH)/bin/withstackcheck ./...

golangci-lint

Not yet supported.

TODO

*ast.IndexExpr support

Cannot check indexed return statements:

func unknown() error {
    var errs []error

    if _, err := json.Marshal(nil); err != nil {
    	errs = append(errs, err)
    }

    if len(errs) > 0 {
    	return errs[0] // cannot check this
    }

Copyright and License

Copyright (c) 2023 Shintaro Kojima. Code released under the MIT license.