tests: TestFindSetLeaves updated with presence container tests

Co-authored-by: Terje Lafton <terje@lafton.io>

ygot/diff_test.go

@@ -196,6 +196,18 @@ type basicStructThree struct {
 	StringValue *string `path:"third-string-value|config/third-string-value"`
 }
 
+type basicStructPresence struct {
+	StringValue *string `path:"string-value" yangPresence:"true"`
+}
+
+func (*basicStructPresence) IsYANGGoStruct() {}
+
+type basicStructPresenceWithStruct struct {
+	StructField *basicStructThree `path:"struct-value" yangPresence:"true"`
+}
+
+func (*basicStructPresenceWithStruct) IsYANGGoStruct() {}
+
 func TestNodeValuePath(t *testing.T) {
 	cmplx := complex(float64(1), float64(2))
 	tests := []struct {
@@ -624,7 +636,44 @@ func TestFindSetLeaves(t *testing.T) {
 				}},
 			}: String("baz"),
 		},
-	}}
+	}, {
+		desc:     "struct with presence container",
+		inStruct: &basicStructPresence{StringValue: String("foo")},
+		inOpts:   []DiffOpt{&WithRespectPresenceContainers{}},
+		want: map[*pathSpec]interface{}{
+			{
+				gNMIPaths: []*gnmipb.Path{{
+					Elem: []*gnmipb.PathElem{{Name: "string-value"}},
+				}},
+			}: nil,
+		},
+	}, {
+		desc:     "struct with presence container but no diff opt",
+		inStruct: &basicStructPresence{StringValue: String("foo")},
+		want: map[*pathSpec]interface{}{
+			{
+				gNMIPaths: []*gnmipb.Path{{
+					Elem: []*gnmipb.PathElem{{Name: "string-value"}},
+				}},
+			}: String("foo"),
+		},
+	}, {
+		desc:     "struct with presence container, empty struct as value",
+		inStruct: &basicStructPresenceWithStruct{StructField: &basicStructThree{}},
+		inOpts:   []DiffOpt{&WithRespectPresenceContainers{}},
+		want: map[*pathSpec]interface{}{
+			{
+				gNMIPaths: []*gnmipb.Path{{
+					Elem: []*gnmipb.PathElem{{Name: "struct-value"}},
+				}},
+			}: nil,
+		},
+	}, {
+		desc:     "struct with presence container, empty struct as a value and no diff opt should be ignored",
+		inStruct: &basicStructPresenceWithStruct{StructField: &basicStructThree{}},
+		want:     map[*pathSpec]interface{}{},
+	},
+	}
 
 	for _, tt := range tests {
 		got, err := findSetLeaves(tt.inStruct, false, tt.inOpts...)