tsの復習

/**
 * Google Books APIのレスポンス
 */
export interface Result {
  items: BookItem[];
  kind: string;
  totalItems: number;
}
 
/**
 * 本の情報
 */
export interface BookItem {
  id: string;
  volumeInfo: {
    title: string;
    authors?: string[];
    publishedDate?: string;
    description?: string;
    publisher?: string;
    imageLinks?: {
      smallThumbnail: string;
      thumbnail: string;
    };
    pageCount: number;
    previewLink?: string;
  };
  saleInfo?: {
    listPrice: {
      amount: number;
    };
  };
}
 
/**
 * query parameters
 */
export interface Params {
  q: string;
  startIndex?: number;
}
 
export interface BookRepositoryInterface {
  get(params: Params): Promise<Result>;
  find(id: string): Promise<BookItem>;
}

import type { BookItem, BookRepositoryInterface, Params, Result } from './types'
import { httpClient } from '../httpClient'
 
export class BookRepository implements BookRepositoryInterface {
  async get(params: Params) {
    const { data } = await httpClient.get<Result>('/', { params })
    return data
  }
 
  async find(id: string) {
    const { data } = await httpClient.get<BookItem>(`/${id}`)
    return data
  }
}