Handle value removal using null val

Signed-off-by: Tamal Saha <tamal@appscode.com>

pkg/values/diff.go

@@ -45,7 +45,7 @@ func getValuesDiff(original, modified map[string]any, prefix string, diff map[st
 				diff[k] = d2
 			}
 		case []any, string, int8, uint8, int16, uint16, int32, uint32, int64, uint64, int, uint, float32, float64, bool, json.Number, nil:
-			if !reflect.DeepEqual(original[k], val) {
+			if origVal, ok := original[k]; !ok || !reflect.DeepEqual(origVal, val) {
 				diff[k] = val
 			}
 		default:
@@ -184,7 +184,7 @@ func getChangedValues(original, modified map[string]any, prefix string, cmds []s
 				cmds = append(cmds, fmt.Sprintf("%s=%v", curKey, val))
 			}
 		case nil:
-			if !reflect.DeepEqual(original[k], val) {
+			if origVal, ok := original[k]; !ok || !reflect.DeepEqual(origVal, val) {
 				cmds = append(cmds, fmt.Sprintf("%s=null", curKey))
 			}
 		default:

pkg/values/diff_test.go

@@ -1,6 +1,7 @@
 package values
 
 import (
+	"reflect"
 	"testing"
 
 	"k8s.io/apimachinery/pkg/util/sets"
@@ -183,6 +184,23 @@ func TestGetChangedValues(t *testing.T) {
 				`nodeSelector.'kubernetes\.io/role'=master`,
 			},
 		},
+		{
+			name: "delete values",
+			args: args{
+				original: map[string]any{
+					"annotations": map[string]any{},
+				},
+				modified: map[string]any{
+					"annotations": map[string]any{
+						"helm.sh/hook": nil,
+					},
+				},
+			},
+			want: []string{
+				`annotations.'helm\.sh/hook'=null`,
+			},
+			wantErr: false,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -197,3 +215,48 @@ func TestGetChangedValues(t *testing.T) {
 		})
 	}
 }
+
+func TestGetValuesMapDiff(t *testing.T) {
+	type args struct {
+		original map[string]any
+		modified map[string]any
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    map[string]any
+		wantErr bool
+	}{
+		{
+			name: "delete values",
+			args: args{
+				original: map[string]any{
+					"annotations": map[string]any{},
+				},
+				modified: map[string]any{
+					"annotations": map[string]any{
+						"helm.sh/hook": nil,
+					},
+				},
+			},
+			want: map[string]any{
+				"annotations": map[string]any{
+					"helm.sh/hook": nil,
+				},
+			},
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := GetValuesMapDiff(tt.args.original, tt.args.modified)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("GetValuesMapDiff() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("GetValuesMapDiff() got = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}