handler: Move input check nearer its kinfolk.

creachadair · Sep 23, 2021 · 69a19b0 · 69a19b0
1 parent 1d7c832
commit 69a19b0
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/handler/handler.go b/handler/handler.go
@@ -263,6 +263,8 @@ func Check(fn interface{}) (*FuncInfo, error) {
  // Check argument values.
  if np := info.Type.NumIn(); np == 0 || np > 2 {
  return nil, errors.New("wrong number of parameters")
+ } else if info.Type.In(0) != ctxType {
+ return nil, errors.New("first parameter is not context.Context")
  } else if np == 2 {
  info.Argument = info.Type.In(1)
  info.IsVariadic = info.Type.IsVariadic()
@@ -272,8 +274,6 @@ func Check(fn interface{}) (*FuncInfo, error) {
  no := info.Type.NumOut()
  if no < 1 || no > 2 {
  return nil, errors.New("wrong number of results")
- } else if info.Type.In(0) != ctxType {
- return nil, errors.New("first parameter is not context.Context")
  } else if no == 2 && info.Type.Out(1) != errType {
  return nil, errors.New("result is not of type error")
  }