TypeScript fix thanks to @tim-hellhake

static/js/schema-form/schema-utils.ts

@@ -121,15 +121,15 @@ export function withDependentSchema(
   schema = mergeSchemas(schema, dependentSchema);
   return typeof oneOf === 'undefined'
     ? schema
-    : withExactlyOneSubschema(schema, definitions, formData, dependencyKey, <unknown[]>oneOf);
+    : withExactlyOneSubschema(schema, definitions, formData, dependencyKey, <JsonSchema[]>oneOf);
 }
 
 export function withExactlyOneSubschema(
   schema: Record<string, unknown>,
   definitions: Record<string, unknown>,
   formData: Record<string, unknown>,
   dependencyKey: string,
-  oneOf: unknown[]
+  oneOf: JsonSchema[]
 ): Record<string, unknown> {
   if (!Array.isArray(oneOf)) {
     throw new Error(`invalid oneOf: it is some ${typeof oneOf} instead of an array`);
@@ -432,3 +432,11 @@ export function getOptionsList(schema: Record<string, unknown>): Record<string,
     });
   }
 }
+
+interface JsonSchema {
+  properties: Record<string, PropertySchema>
+}
+
+interface PropertySchema {
+  type: string
+}