如何扩展打字稿接口？

Question

So i have interface for the request that has header from IoperationParam and body would be same as patientList that is array of object but it throws error patientId can not assigsigned to IGetSpecialtyQuestionsParam any idea what needs to be corrected here ?

main.interface.ts

    export interface IGetSpecialtyQuestionsParam extends IOperationParam {
        patientList: (ISpecialtyQuestionsEntity)[];
    }
    export interface ISpecialtyQuestionsEntity {
        /**
         * <H3>This maps to ESL patientId<H3>
         */
        patientId: string;
        /**
         * 1982-01-10
         */
        dateOfBirth: string;
        /**
         * Female
         */
        gender: "Male"|"Female";
        /**
         * We can default this;
         * Specialty HBS
         */

        sourceSystem: string;


        rxInfo?: (RxInfoEntity)[] | null;
    }

export interface IOperationParam {
    appName: string;
    appId: string
}

Answer 1

You seem to be confusing classes and interfaces. Interfaces only define the shape of the data, not default values.

Your interfaces should be:

export interface IOperationParam {
  appName: string;
  appId: string
}

export interface IGetSpecialtyQuestionsParam extends IOperationParam {
  patientList: ISpecialtyQuestionsEntity[];
}

export interface ISpecialtyQuestionsEntity {
  patientId: string;
  dateOfBirth: string;
  gender: string;
  sourceSystem: string;
  rxInfo?: RxInfoEntity[];
}

The error you stated: "...patientId can not assigsigned to IGetSpecialtyQuestionsParam..."

is happening because IGetSpecialtyQuestionsParam extends IOperationParam which doesn't have the property: patientId .

So, you need to either have patientId in the IOperationParam interface, or add it as part of the IGetSpecialtyQuestionsParam interface, or extend a common interface... whatever works best for your app.