gistfile1.txt

class CustomError extends Error {
    static createCustomErrorResposne(statusCode: number, answer?: string): ErrorResponseType {
        return {
            statusCode: statusCode,
            answer: answer = ''
        }
    }

    static isErrorInstanceOfCustomError(error: any): boolean {
        if(error instanceof CustomError) return true
        else return false;
    }

    createCustomErrorMessage(errorMessage: string): CustomErrorMessageType {
        return {
            answer: errorMessage
        }
    }
}

# 

class TestingLessonValidation {
    static validateHeader(headers: UserHeaders, errorMessage: string): void {
        if(!headers["X-userr"]) {
            const error = new CustomError();
            throw error.createCustomErrorMessage(errorMessage);
        }
    }
}


CustomError.isErrorInstanceOfCustomError(e) // -> false