Restored condition to check for number of parameters above expected n…

…umber (now 4). Also changed for loop to be more idiomatic.

plugin.go

@@ -163,38 +163,35 @@ func ParseOptions(req *plugin_go.CodeGeneratorRequest) (*PluginOptions, error) {
 	}
 
 	parts := strings.Split(params, ",")
-	if len(parts) < 2 {
+	if len(parts) < 2 || len(parts) > 4 {
 		return nil, fmt.Errorf("Invalid parameter: %s", params)
 	}
 
 	options.TemplateFile = parts[0]
 	options.OutputFile = path.Base(parts[1])
 
-	if len(parts) > 2 {
-		extraOptions := parts[2:]
-
-		for i := 0; i < len(extraOptions); i++ {
-			switch i {
-			case 0: // Third option
-				switch extraOptions[i] {
-				case "source_relative":
-					options.SourceRelative = true
-				case "default":
-					options.SourceRelative = false
-				default:
-					return nil, fmt.Errorf("Invalid parameter: %s", params)
-				}
-			case 1: // Fourth option
-				switch extraOptions[i] {
-				case "separate_files":
-					options.SeparateFiles = true
-				case "default":
-					options.SeparateFiles = false
-				default:
-					return nil, fmt.Errorf("Invalid parameter: %s", params)
-				}
+	extraOptions := parts[2:]
+
+	for i := range extraOptions {
+		switch i {
+		case 0: // Third option
+			switch extraOptions[i] {
+			case "source_relative":
+				options.SourceRelative = true
+			case "default":
+				options.SourceRelative = false
+			default:
+				return nil, fmt.Errorf("Invalid parameter: %s", params)
+			}
+		case 1: // Fourth option
+			switch extraOptions[i] {
+			case "separate_files":
+				options.SeparateFiles = true
+			case "default":
+				options.SeparateFiles = false
+			default:
+				return nil, fmt.Errorf("Invalid parameter: %s", params)
 			}
-
 		}
 	}