Possible bug with anyOf/oneOf when the selected schema changes from type:string to type:object

[lindolo25]

Prerequisites

• I have searched the existing issues
• I understand that providing a SSCCE example is tremendously useful to the maintainers.
• I have read the documentation
• Ideally, I'm providing a sample JSFiddle, Codesandbox.io or preferably a shared playground link demonstrating the issue.

What theme are you using?

bootstrap-4

Version

5.1.0

Current Behavior

Given an anyOf or a oneOf composition schema with two options. First an object with one property of type string and second just a string value. When option 2 has a value (example "adsads") and the dropdown is changed to the option 1. The value is set to this:

{
  "0": "a",
  "1": "d",
  "2": "s",
  "3": "a",
  "4": "d",
  "5": "s"
}

It continues to keep those added properties after a value is give to option 1 string property:

{
  "0": "a",
  "1": "d",
  "2": "s",
  "3": "a",
  "4": "d",
  "5": "s",
  "foo": "werwer"
}

Even if the "additionalProperties": false is set the an error will not be presented.

The scenario will work as expected if option 2 has another type of value, I tested number and boolean.

Expected Behavior

After switching to the Option 1, the value should be and empty object {}.

Steps To Reproduce

1. Open the setup
2. Select Option 1
3. Type a value for "foo"

Environment

- OS: Fedora 38 (Workstation Edition)
- Node: v18.16.0
- npm: v9.5.1

Anything else?

I narrow it down to the result of the function schemaUtils.sanitizeDataForNewSchema(newOption, oldOption, formData) in line 122 of the MultiSchemaField.tsx file.

react-jsonschema-form/packages/core/src/components/fields/MultiSchemaField.tsx

Line 122 in 42e138c

let newFormData = schemaUtils.sanitizeDataForNewSchema(newOption, oldOption, formData);

After that function is executed, newFormData takes that value and later on is used to update the field value in line 128. I'll update later if I'm able to find out more about this issue.

[nickgros]

Definitely something unusual happening here. Thanks for the report @lindolo25 ! If you can open a PR to fix this we would be happy to review and accept it.