Medium TypeScript GET+ POST RESTful client - ApiClient

ApiClient.ts

import Axios, { AxiosInstance, AxiosRequestConfig, AxiosResponse } from "axios";

type HttpVerb = "GET" | "POST" | "PUT" | "DELETE" | "PATCH";

class ApiClient {
  private static singleton: ApiClient;
  private readonly instanceAxios: AxiosInstance;
  private URL: string = "https://localhost:44300/";

  private constructor() {
    this.instanceAxios = Axios.create({
      baseURL: `${this.URL}api/`,
      headers: {
        "Content-Type": "application/json",
        Accept: "application/json",
      },
    });
  }

  public static get instance(): ApiClient {
    if (!ApiClient.singleton) {
      this.singleton = new ApiClient();
    }

    return ApiClient.singleton;
  }

  private async request<T>(method: HttpVerb, url: string, body?: any): Promise<T> {
    const requestConfig: AxiosRequestConfig = {
      method: method === "GET" ? "GET" : "POST",
      url: url,
      headers: {/*... */},
    };
    // Use X-HTTP-Method-Override to use all HTTP verbs
    // Verbs will be encapsulated in POST Header
    if (method !== "GET" && method !== "POST")
      requestConfig.headers["X-HTTP-Method-Override"] = method;

    if (body) {
      requestConfig.data = body;
    }

    try {
      const response: AxiosResponse = await this.instanceAxios(requestConfig);
      return response.data as T;
    } catch (error) {
      throw new Error(error.response.data);
    }
  }

  public async get<T>(url: string): Promise<T> {
    try {
      const response: AxiosResponse = await this.instanceAxios.get(url);
      return response.data as T;
    } catch (error) {
      throw new Error(/*..*/);
    }
  }

  public async post<T>(url: string, body: any): Promise<T> {
    return this.request("POST", url, body);
  }

  public async put<T>(url: string, body: any): Promise<T> {
    return this.request("PUT", url, body);
  }

  public async patch<T>(url: string, body?: any, ): Promise<T> {
    return this.request("PATCH", url, body);
  }

  public delete<T>(url: string): Promise<T> {
    return this.request("DELETE", url);
  }
}

export default ApiClient.instance;