Using $ref in root causes stack overflow

[uuf6429]

Describe the bug

Using a reference in the root schema seems to cause a stack overflow / infinite loop/recursion.

Expected behavior

It should work as expected, or at least show a warning/error that this case is not supported.

Steps to reproduce the issue

Use the following schema

{
  "type": "object",

  "$ref": "#/definitions/person",

  "definitions": {

    "person": {
       "properties": {
         "name": {
           "type": "string"
         }
       }
    }

  }
}

(for example on https://prismatic.io/docs/jsonforms/playground/)

I guess same thing would happen on https://jsonforms-editor.netlify.app/, but that site seems quite broken (I keep getting white/blank screens)

Screenshots

No response

Which Version of JSON Forms are you using?

n/a

Package

No response

Additional context

No response

[lucas-koehler]

Hi @uuf6429 ,
thanks for the report! The root cause for this seems to be here:

jsonforms/packages/core/src/util/resolvers.ts

Lines 112 to 133 in 393c4dc

	export const resolveSchema = (
	schema: JsonSchema,
	schemaPath: string,
	rootSchema: JsonSchema
	): JsonSchema => {
	const segments = schemaPath?.split('/').map(decode);
	return resolveSchemaWithSegments(schema, segments, rootSchema);
	};
	const resolveSchemaWithSegments = (
	schema: JsonSchema,
	pathSegments: string[],
	rootSchema: JsonSchema
	): JsonSchema => {
	if (isEmpty(schema)) {
	return undefined;
	}
	// use typeof because schema can by of any type - check singleSegmentResolveSchema below
	if (typeof schema.$ref === 'string') {
	schema = resolveSchema(rootSchema, schema.$ref, rootSchema);
	}

There is no handling for schema being rootSchema causing an endless loop.