Fix check filter bug: check if includeGroups and excludeGroups are mutually exclusive

checks/check_filter.go

@@ -30,7 +30,7 @@ type CheckFilter struct {
 
 // NewCheckFilter is a constructor to initialize an instance of CheckFilter
 func NewCheckFilter(includeGroups, excludeGroups, includeChecks, excludeChecks []string) (CheckFilter, error) {
-	if len(includeGroups) > 0 && len(excludeChecks) > 0 {
+	if len(includeGroups) > 0 && len(excludeGroups) > 0 {
 		return CheckFilter{}, fmt.Errorf("cannot specify both include and exclude group conditions")
 	}
 	if len(includeChecks) > 0 && len(excludeChecks) > 0 {

checks/check_filter_test.go

@@ -0,0 +1,38 @@
+/*
+Copyright 2019 DigitalOcean
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package checks
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGroupError(t *testing.T) {
+	_, err := NewCheckFilter([]string{"basic"}, []string{"basic"}, nil, nil)
+
+	assert.Error(t, err)
+	assert.Equal(t, fmt.Errorf("cannot specify both include and exclude group conditions"), err)
+}
+
+func TestCheckError(t *testing.T) {
+	_, err := NewCheckFilter(nil, nil, []string{"foo"}, []string{"bar"})
+
+	assert.Error(t, err)
+	assert.Equal(t, fmt.Errorf("cannot specify both include and exclude check conditions"), err)
+}