Valkyrie is a utility that helps you aggregate multiple errors in Go, while maintaining thread safety.
go get -u github.com/gojektech/valkyrie
Consider the case of an error prone operation, where there is a possibility of encountering multiple, mutually independant errors while running an operation. We can use Valkyrie to collate all the errors into a single error which we can then return:
func errorProneOperation(n int) error {
// Create a new Multierror instance, which implements the error interface
errs := new(valkyrie.MultiError)
for i := 0; i < n; i++ {
errs.Push(fmt.Sprintf("error in iteration %d", i))
}
// When you have to return an error, call the `HasError` method
// which returns nil if the length of errors is 0, and returns the errs instance itself if its not
return errs.HasError()
}Now, the errorProneOperation can be used just like a function that returns a single error:
func main() {
err := errorProneOperation(3)
if err != nil {
fmt.Println("err :", err)
}
// Outputs:
// err : error in iteration 0, error in iteration 1, error in iteration 2
err = errorProneOperation(0)
if err != nil {
fmt.Println("err :", err)
}
// Does not output anything
}For more documentation, you can visit godoc.org.
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