Fix MarshalJSON of array

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

kyaml/yaml/types.go

@@ -688,11 +688,18 @@ func (rn *RNode) MarshalJSON() ([]byte, error) {
 		return nil, err
 	}
 
+	if rn.YNode().Kind == SequenceNode {
+		var a []interface{}
+		if err := Unmarshal([]byte(s), &a); err != nil {
+			return nil, err
+		}
+		return json.Marshal(a)
+	}
+
 	m := map[string]interface{}{}
 	if err := Unmarshal([]byte(s), &m); err != nil {
 		return nil, err
 	}
-
 	return json.Marshal(m)
 }
 

kyaml/yaml/types_test.go

@@ -105,21 +105,43 @@ metadata:
 }
 
 func TestRNode_MarshalJSON(t *testing.T) {
-	instance, err := Parse(`
+	tests := []struct {
+		name string
+		ydoc string
+		want string
+	}{
+		{
+			name: "object",
+			ydoc: `
 hello: world
-`)
-	if !assert.NoError(t, err) {
-		t.FailNow()
+`,
+			want: `{"hello":"world"}`,
+		},
+		{
+			name: "array",
+			ydoc: `
+- name: s1
+- name: s2
+`,
+			want: `[{"name":"s1"},{"name":"s2"}]`,
+		},
 	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			instance, err := Parse(tt.ydoc)
+			if !assert.NoError(t, err) {
+				t.FailNow()
+			}
 
-	actual, err := instance.MarshalJSON()
-	if !assert.NoError(t, err) {
-		t.FailNow()
-	}
+			actual, err := instance.MarshalJSON()
+			if !assert.NoError(t, err) {
+				t.FailNow()
+			}
 
-	expected := `{"hello":"world"}`
-	if !assert.Equal(t,
-		strings.TrimSpace(expected), strings.TrimSpace(string(actual))) {
-		t.FailNow()
+			if !assert.Equal(t,
+				strings.TrimSpace(tt.want), strings.TrimSpace(string(actual))) {
+				t.FailNow()
+			}
+		})
 	}
 }