Toolbox: TypeScript throws compilation errors when adding a new toolbox subitem

[JaneSjs]

T19740 - TS compilation errors for an IQuestionToolboxItem object passed to the addSubitem function
https://surveyjs.answerdesk.io/internal/ticket/details/T19740

---

creator-angular.zip

import { IQuestionToolboxItem } from "survey-creator-core";

const textItem: IQuestionToolboxItem = creator.toolbox.getItemByName("text");
const textItemConfig: IQuestionToolboxItem = {
        name: "postalCode",
        title: "Postcode",
        json: {
            type: "text",
            autocomplete: "postal-code",
            hideNumber: true,
            maxLength: 0,
            maskType: "pattern",
            maskSettings: {
                pattern: "9999 AA",
            },
            placeholder: "1234 AB",
        },
}

textItem.addSubitem(textItemConfig);

The following compilation errors occur:

• ...is missing the following properties from type 'IQuestionToolboxItem': iconName, className

Error: src/app/survey-creator/survey-creator.component.ts:35:11 - error TS2739: Type '{ name: string; title: string; json: { type: string; autocomplete: string; hideNumber: boolean; maxLength: number; maskType: string; maskSettings: { pattern: string; }; placeholder: string; }; }' is missing the following properties from type 'IQuestionToolboxItem': iconName, className

• An argument for 'index' was not provided.

 node_modules/survey-creator-core/typings/toolbox.d.ts:75:48
    75     addSubitem?(subitem: IQuestionToolboxItem, index: number): void;
                                                      ~~~~~~~~~~~~~
    An argument for 'index' was not provided.

• Cannot invoke an object which is possibly 'undefined'

TS2722: Cannot invoke an object which is possibly 'undefined'.