empty list or map item return error

k8sdeps/kunstruct/factory.go

@@ -7,6 +7,7 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"strconv"
 	"strings"
 
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
@@ -108,5 +109,30 @@ func (kf *KunstructuredFactoryImpl) validate(u unstructured.Unstructured) error
 	if u.GetName() == "" {
 		return fmt.Errorf("missing metadata.name in object %v", u)
 	}
+
+	if result, path := checkItemNil(u.Object); result {
+		return fmt.Errorf("empty item at %v in object %v", path, u)
+	}
 	return nil
 }
+
+func checkItemNil(in interface{}) (bool, string) {
+	if in == nil {
+		return true, ""
+	}
+	switch v := in.(type) {
+	case map[string]interface{}:
+		for key, s := range v {
+			if result, path := checkItemNil(s); result {
+				return result, key + "/" + path
+			}
+		}
+	case []interface{}:
+		for index, s := range v {
+			if result, path := checkItemNil(s); result {
+				return result, "[" + strconv.Itoa(index) + "]/" + path
+			}
+		}
+	}
+	return false, ""
+}

pkg/resource/factory_test.go

@@ -98,6 +98,21 @@ items:
 	patch7 := `
 apiVersion: v1
 kind: List
+`
+	patchList5 := types.PatchStrategicMerge("patch8.yaml")
+	patch8 := `
+apiVersion: builtin
+kind: ConfigMapGenerator
+metadata:
+  name: kube100-site
+  labels:
+    app: web
+    testList:
+      - testA
+      - 
+literals:
+- FRUIT=apple
+- VEGETABLE=carrot
 `
 	testDeploymentSpec := map[string]interface{}{
 		"template": map[string]interface{}{
@@ -139,6 +154,7 @@ kind: List
 	l.AddFile("/"+string(patchList2), []byte(patch5))
 	l.AddFile("/"+string(patchList3), []byte(patch6))
 	l.AddFile("/"+string(patchList4), []byte(patch7))
+	l.AddFile("/"+string(patchList5), []byte(patch8))
 
 	tests := []struct {
 		name        string
@@ -188,6 +204,12 @@ kind: List
 			expectedOut: []*Resource{},
 			expectedErr: false,
 		},
+		{
+			name:        "listWithEmptyList",
+			input:       []types.PatchStrategicMerge{patchList5},
+			expectedOut: []*Resource{},
+			expectedErr: true,
+		},
 	}
 	for _, test := range tests {
 		rs, err := factory.SliceFromPatches(l, test.input)