Fix issue with kyaml json unmarshalling

kyaml/yaml/types.go

@@ -697,7 +697,17 @@ func (rn *RNode) MarshalJSON() ([]byte, error) {
 }
 
 func (rn *RNode) UnmarshalJSON(b []byte) error {
-	r, err := Parse(string(b))
+	m := map[string]interface{}{}
+	if err := json.Unmarshal(b, &m); err != nil {
+		return err
+	}
+
+	c, err := Marshal(m)
+	if err != nil {
+		return err
+	}
+
+	r, err := Parse(string(c))
 	if err != nil {
 		return err
 	}

kyaml/yaml/types_test.go

@@ -50,21 +50,58 @@ spec:
 }
 
 func TestRNode_UnmarshalJSON(t *testing.T) {
+	testCases := []struct {
+		testName string
+		input    string
+		output   string
+	}{
+		{
+			testName: "simple document",
+			input:    `{"hello":"world"}`,
+			output:   `hello: world`,
+		},
+		{
+			testName: "nested structure",
+			input: `
+{
+  "apiVersion": "apps/v1",
+  "kind": "Deployment",
+  "metadata": {
+    "name": "my-deployment",
+    "namespace": "default"
+  }
+}
+`,
+			output: `
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: my-deployment
+  namespace: default
+`,
+		},
+	}
+
+	for i := range testCases {
+		tc := testCases[i]
+		t.Run(tc.testName, func(t *testing.T) {
 			instance := &RNode{}
-	err := instance.UnmarshalJSON([]byte(`{"hello":"world"}`))
+			err := instance.UnmarshalJSON([]byte(tc.input))
 			if !assert.NoError(t, err) {
 				t.FailNow()
 			}
+
 			actual, err := instance.String()
 			if !assert.NoError(t, err) {
 				t.FailNow()
 			}
 
-	expected := `{"hello": "world"}`
 			if !assert.Equal(t,
-		strings.TrimSpace(expected), strings.TrimSpace(actual)) {
+				strings.TrimSpace(tc.output), strings.TrimSpace(actual)) {
 				t.FailNow()
 			}
+		})
+	}
 }
 
 func TestRNode_MarshalJSON(t *testing.T) {