TypeScript Fullstack Engineer Assignment by Sinan Lee

fullstack/.gitignore

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+node_modules
+package-lock.json
+tests
+yarn.lock
+dist
+.env*

fullstack/README.md

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+# 项目说明
+
+- 本框架原本使用 node+typescript+express+mysql 搭建，修改后使用 redis 实现数据存储。
+  因此删掉了大多数不必要的文件，只保留了实现 api 的基础框架。
+- 此项目代码只考虑了长域名和短域名的转换，长域名唯一性校验和 mysql 持久化存储没有实现。
+- 短域名存储接口 url/save
+- 短域名读取接口 url/get
+
+# 递交作业说明
+
+1. 源代码
+   见代码。
+2. 单元测试代码以及单元测试覆盖率(覆盖率请勿提交整个目录，一张图片或一个 text table 即可)
+   ![nyc](./images/nyc.png)
+3. API 集成测试案例以及测试结果
+   ![api-save](./images/api-save.png)
+   ![api-get](./images/api-get.png)
+4. 简单的框架设计图，以及所有做的假设
+   ![简单架构图](./images/architecture.png)
+   假设：
+   - 怎么保证所有的短 url 唯一？
+     使用时间戳+10 位随机数生成一个数字，不能说完全唯一，但是重复率极小极小。
+   - 怎么保证短 url 长度小于 8 位？
+     时间戳长度为 13 位，经过 62 进制编码后长度绝对小于等于 8 位。
+   - 怎么保证长域名存储的唯一性？
+     本项目只考虑了长短域名的对应，长域名如果想做唯一性校验，可以在持久化到 mysql 数据库时做唯一索引，redis 这里只考虑短域名的唯一，且不考虑获取长域名对应的短域名情况
+5. 涉及的 SQL 或者 NoSQL 的 Schema，注意标注出 Primary key 和 Index 如果有。
+   本项目数据只涉及 redis 存储，schema 为 db0，key（短域名）- value（长域名）
+
+## 使用说明
+
+安装:
+
+> yarn
+
+启动：
+
+> yarn start
+
 # TypeScript Fullstack Engineer Assignment
 
 ### Typescript 实现短域名服务（细节可以百度/谷歌）

fullstack/app.ts

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+const express = require("express");
+const app = express();
+const createError = require("http-errors");
+const bodyParser = require("body-parser");
+
+import { ErrorMessage } from "./common/exception/exception-const";
+import { logger } from "./common/logger";
+import * as UrlApi from "./router/system/url";
+
+// 服务器设置
+app.use(bodyParser.json({ limit: "50mb" }));
+app.use(express.json());
+app.use(express.urlencoded({ extended: false }));
+
+// node服务生命监测
+app.use("*/ping", (req: any, res: any) => {
+  res.send("pong");
+});
+
+// 注册接口
+app.use("/url", UrlApi.router);
+
+// 404
+app.use(function (req: any, res: any, next: any) {
+  next(createError(404));
+});
+
+// 错误处理
+app.use(function (err: any, req: any, res: any, next: any) {
+  if (err.name === "UnauthorizedError") {
+    res.send(ErrorMessage.AUTH_LOGIN);
+  }
+  res.locals.message = err.message;
+  res.locals.error = err;
+  res.status(err.status || 500);
+  res.send(err.message);
+});
+
+app.listen(8888, () => {
+  logger.info("The app is listening on port 8888!");
+});

fullstack/blogic/base-blogic.ts

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+import { BLogicContext } from "../common/base";
+
+export abstract class BaseBLogic {
+  abstract doExecute(context: BLogicContext<any>): any;
+  needAuth: boolean = false;
+  needLogger: boolean = false;
+
+  public async execute(context: BLogicContext<any>) {
+    return await this.doExecute(context);
+  };
+}
+
+

fullstack/blogic/url/get.ts

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+/**
+ * 短域名读取接口：接受短域名信息，返回长域名信息。
+ */
+
+import { BLogicContext } from "../../common/base";
+import { BaseModel } from "../../model/base-model";
+import { BaseBLogic } from "../base-blogic";
+
+export class ShortUrlGetBLogic extends BaseBLogic {
+  public async doExecute(context: BLogicContext<any>) {
+    const { url } = context.input;
+    const baseModel: BaseModel = new BaseModel(context.proxy);
+    const res: string = await baseModel.get(url);
+    if (res) {
+      return {
+        url: res,
+      };
+    }
+  }
+}

fullstack/blogic/url/save.ts

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+/**
+ * 短域名存储接口：接受长域名信息，返回短域名信息
+ */
+
+import { BLogicContext } from "../../common/base";
+import { BaseBLogic } from "../base-blogic";
+import { BaseModel } from "../../model/base-model";
+import { getShortUrl } from "../../utils/common";
+
+export class ShortUrlSaveBLogic extends BaseBLogic {
+  public async doExecute(context: BLogicContext<any>) {
+    const { url } = context.input;
+    const baseModel: BaseModel = new BaseModel(context.proxy);
+    const key: string = getShortUrl();
+    const res: string = await baseModel.set(key, url);
+    if (res && res == "OK") {
+      return {
+        url: key,
+      };
+    }
+  }
+}

fullstack/common/base.ts

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+import { DBProxy } from './db-proxy';
+
+// 请求
+export interface BLogicContext<T> {
+  session: {
+    permission: string;
+    token: string;
+    host: string;
+    uid: string;
+    username: string;
+    appid: string;
+  };
+  input: T;
+  params: any;
+  proxy: DBProxy;
+  originalUrl: string; // 请求路径
+  reqNo: string; // 请求编号
+}
+
+// 返回
+export interface ResultData {
+  ok: boolean;
+  data: object;
+  err_code?: number;
+  err_msg?: string;
+}

fullstack/common/db-proxy.ts

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+import { logger } from "./logger";
+
+const redis = require("redis");
+
+export class DBProxy {
+  private clientNo: string;
+  private client: any;
+  constructor() {
+    this.clientNo = "DBProxy" + Math.ceil(Math.random() * 9999);
+  }
+
+  public async connect() {
+    if (!this.client) {
+      this.client = redis.createClient({
+        socket: {
+          host: "127.0.0.1",
+          port: 6379,
+        },
+      });
+      this.client.on("error", function (err: any) {
+        console.log("Error " + err);
+      });
+    }
+    await this.client.connect();
+  }
+
+  public async disconnect() {
+    await this.client.disconnect();
+  }
+
+  public async set(key: string, value: string) {
+    logger.debug(
+      this.clientNo + `: dbproxy set: key=[${key}] value=[${value}]`
+    );
+    try {
+      const res = await this.client.set(key, value);
+      return res;
+    } catch (error) {
+      logger.error(`DBProxy error: ${this.clientNo} - ${error}`);
+      return;
+    }
+  }
+
+  public async get(key: string) {
+    logger.debug(this.clientNo + `: dbproxy get: key=[${key}]`);
+    try {
+      const res = await this.client.get(key);
+      return res;
+    } catch (error) {
+      logger.error(`DBProxy error: ${this.clientNo} - ${error}`);
+      return;
+    }
+  }
+}

fullstack/common/exception/exception-const.ts

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+export enum ErrorConst {
+  AUTH_LOGIN = 999,
+  SQL_ERROR = 1001,
+  External_API = 1002,
+  WX_AUTH_TOKEN = 4001,
+  WX_CREATE_MENU = 4002,
+}
+
+export enum ErrorMessage {
+  AUTH_LOGIN = "登录验证失败",
+  SQL_ERROR = "数据库操作失败",
+}
+
+/**
+ * 返回错误信息
+ * @param errCode：number 错误码
+ * @param msg：string[] 错误提示
+ * @returns 字符串可能是内部错误，直接返回
+ * @returns 数组或者不存在，用定义好的错误提示和msg拼接
+ * @returns 其余情况（对象）序列化后返回
+ */
+export function getErrorMessage(errCode: number, msg?: string[]) {
+  if (typeof msg === "string") {
+    return msg;
+  } else if (Array.isArray(msg) || !msg) {
+    let code = ErrorConst[errCode];
+    let info: any = ErrorMessage[`${code as keyof typeof ErrorMessage}`];
+    if (info && msg && msg.length == 1) {
+      info = `${msg[0]}${info}`;
+    }
+    if (info && msg && msg.length > 1) {
+      info = `${msg[0]}${info}${msg[1]}`;
+    }
+    if (!info && msg && msg.length) {
+      info = msg[0];
+    }
+    return info;
+  } else {
+    return JSON.stringify(msg);
+  }
+}

fullstack/common/exception/permission-exception.ts

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+import { getErrorMessage } from './exception-const';
+
+export class PermissionException extends Error {
+  code: number;
+  msg: string;
+  err: Error | undefined;
+  constructor(errCode: number, errMsg?: string[], err?: Error) {
+    let msg: string = getErrorMessage(errCode, errMsg);
+    super(msg);
+    this.code = errCode;
+    this.msg = msg;
+    if (err) {
+      this.err = err;
+    }
+  }
+}

fullstack/common/exception/system-exception.ts

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+import { getErrorMessage } from "./exception-const";
+
+export class SystemException extends Error {
+  code: number;
+  msg: string;
+  err: Error | undefined;
+  constructor(errCode: number, errMsg?: string[], err?: Error) {
+    let msg: string = getErrorMessage(errCode, errMsg);
+    super(msg);
+    this.code = errCode;
+    this.msg = msg;
+    if (err) {
+      this.err = err;
+    }
+  }
+}

fullstack/common/logger.ts

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+import * as log4js from 'log4js';
+export const logger = log4js.getLogger();
+export const reqLog = log4js.getLogger('reqLog');
+const level = process.env.LOG_LEVEL ? process.env.LOG_LEVEL : 'debug';
+log4js.configure({
+  appenders: {
+    // 控制台输入
+    console: { type: 'console' },
+  },
+  categories: {
+    // 默认日志
+    default: {
+      appenders: ['console'],
+      level: level,
+    },
+    reqLog: {
+      appenders: ['console'],
+      level: level,
+    },
+  },
+});

fullstack/model/base-model.ts

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+import { ErrorConst } from "../common/exception/exception-const";
+import { SystemException } from "../common/exception/system-exception";
+import { DBProxy } from "../common/db-proxy";
+import { logger } from "../common/logger";
+
+export class BaseModel {
+  constructor(private dbproxy: DBProxy) {}
+  async set(key: string, value: string) {
+    let r: string = await this.dbproxy.set(key, value);
+    return r;
+  }
+
+  async get(key: string) {
+    let r: string = await this.dbproxy.get(key);
+    return r;
+  }
+}