commands: Refactored Command#Run function signature to (req Request, res Response)

command.go

@@ -14,7 +14,7 @@ var log = u.Logger("command")
 
 // Function is the type of function that Commands use.
 // It reads from the Request, and writes results to the Response.
-type Function func(Request) (interface{}, error)
+type Function func(Request, Response)
 
 // Marshaler is a function that takes in a Response, and returns an io.Reader
 // (or an error on failure)
@@ -95,21 +95,12 @@ func (c *Command) Call(req Request) Response {
 		return res
 	}
 
-	output, err := cmd.Run(req)
-	if err != nil {
-		// if returned error is a commands.Error, use its error code
-		// otherwise, just default the code to ErrNormal
-		switch e := err.(type) {
-		case *Error:
-			res.SetError(e, e.Code)
-		case Error:
-			res.SetError(e, e.Code)
-		default:
-			res.SetError(err, ErrNormal)
-		}
+	cmd.Run(req, res)
+	if res.Error() != nil {
 		return res
 	}
 
+	output := res.Output()
 	isChan := false
 	actualType := reflect.TypeOf(output)
 	if actualType != nil {
@@ -140,7 +131,6 @@ func (c *Command) Call(req Request) Response {
 		}
 	}
 
-	res.SetOutput(output)
 	return res
 }
 

command_test.go

@@ -2,8 +2,8 @@ package commands
 
 import "testing"
 
-func noop(req Request) (interface{}, error) {
-	return nil, nil
+func noop(req Request, res Response) {
+	return
 }
 
 func TestOptionValidation(t *testing.T) {