How to define Workflow return values in Go

A Go-based Workflow Definition can return either just an error or a customValue, error combination. Again, the best practice here is to use a struct type to hold all custom values.

type YourWorkflowResponse struct{
 WorkflowResultFieldOne string
 WorkflowResultFieldTwo int
}

func YourWorkflowDefinition(ctx workflow.Context, param YourWorkflowParam) (YourWorkflowResponse, error) {
 // ...
 if err != nil {
   return "", err
 }
 responseVar := YourWorkflowResponse {
   FieldOne: "super",
   FieldTwo: 1,
 }
 return responseVar, nil
}

A Workflow Definition written in Go can return both a custom value and an error. However, it's not possible to receive both a custom value and an error in the calling process, as is normal in Go. The caller will receive either one or the other. Returning a non-nil error from a Workflow indicates that an error was encountered during its execution and the Workflow Execution should be terminated, and any custom return values will be ignored by the system.