Cannot distinguish the "TextNode" and the "ArrayNode" with single value for oneOf

[rongyj]

When schema has "oneOf" as below:

  "values": {
            "oneOf": [
              {
                "type": "string",
                "nullable": true
              },
              {
                "type": "array",
                "nullable": true,
                "items": {
                  "type": "string"
                }
              }
            ]
          },

When input test data is :

values: "test"

It has a validation error:

should be valid to one and only one of the schemas but more than one schemas {{"type":"string","nullable":true}{"type":"array","nullable":true,"items":{"type":"string"}}} are valid

when input data is :

values : ["test"]

It is fine.

[rongyj]

Create a PR #432 which include the fixes for issue428 too.

[stevehu]

@rongyj I have rolled back your changes for issue428 and issue425 as it breaks the issue456. Once I rolled back and I can see both 425 and 428 test cases are passed. If you still have the issues, please review the updates and make sure that 456 is not broken. Thanks.