better logging, errors, fmt

command.go

@@ -76,7 +76,7 @@ func (c *Command) Call(req *Request, re ResponseEmitter, env Environment) {
 
 	err := c.call(req, re, env)
 	if err != nil {
-		log.Debug("error occured in call, closing with error: %s", err)
+		log.Debugf("error occured in call, closing with error: %s", err)
 	}
 
 	closeErr = re.CloseWithError(err)

encoding.go

@@ -94,7 +94,7 @@ func MakeTypedEncoder(f interface{}) func(*Request) func(io.Writer) Encoder {
 
 	return MakeEncoder(func(req *Request, w io.Writer, i interface{}) error {
 		if reflect.TypeOf(i) != valType {
-			return fmt.Errorf("unexpected type: %T", i)
+			return fmt.Errorf("unexpected type %T, expected %v", i, valType)
 		}
 
 		out := val.Call([]reflect.Value{

writer.go

@@ -114,7 +114,9 @@ func (re *writerResponseEmitter) CloseWithError(err error) error {
 		return re.Close()
 	}
 
-	cwe, ok := re.c.(interface{ CloseWithError(error) error })
+	cwe, ok := re.c.(interface {
+		CloseWithError(error) error
+	})
 	if ok {
 		re.closed = true
 		return cwe.CloseWithError(err)