基于JS实现将JSON数据转换为TypeScript类型声明的工具

{
  "name": "John",
  "age": 30,
  "address": {
    "city": "New York",
    "state": "NY"
  },
  "hobbies": [
    "reading",
    "traveling"
  ]
}

interface JsonType {
  name: string;
  age: number;
  address: {
    city: string;
    state: string;
  };
  hobbies: string[];
}

{
  "name": "John",
  "age": 30,
  "address": {
    "city": "New York",
    "state": "NY",
    "postalCode": 10001
  },
  "friends": [
    {
      "name": "Jane",
      "age": 28,
      "address": {
        "city": "Los Angeles",
        "state": "CA"
      }
    },
    {
      "name": "Bob",
      "age": 35,
      "address": {
        "city": "Chicago",
        "state": "IL"
      }
    }
  ],
  "hobbies": [
    "reading",
    "traveling",
    {
      "name": "swimming",
      "location": "pool"
    }
  ]
}

interface JsonType {
  name: string;
  age: number;
  address: {
    city: string;
    state: string;
    postalCode: number;
  };
  friends: {
    name: string;
    age: number;
    address: {
      city: string;
      state: string;
    };
  }[];
  hobbies: (string | {
    name: string;
    location: string;
  })[];
}

  const fs = require('fs-extra');
  const commander = require('commander');

  /**
   * 将 JSON 数据转换为 TypeScript 类型定义
   * @param {Object} object - 要转换的 JSON 对象
   * @param {string} [name=JsonType] - 转换后的类型名称
   * @param {string} [namespace] - 转换后的命名空间
   * @returns {string} - 转换后的 TypeScript 类型定义字符串
   */
  function jsonToTs(object, name = 'JsonType', namespace) {
      const getType = value => {
          let typeRes = ``;
          if (Array.isArray(value)) {
              value.forEach(item => {

                  let subType = getType(item);
                  if (typeRes.split('|').indexOf(subType) < 0) {
                      typeRes += subType
                      typeRes += "|"
                  }
              })
              typeRes = typeRes.substring(0, typeRes.length - 1)
              return `(${typeRes})[]`;
          }
          if (typeof value === 'object' && value !== null) {
              const props = Object.entries(value)
                  .map(([key, val]) => `${key}: ${getType(val)}`)
                  .join('; ');
              return `{ ${props} }`;
          }
          return typeof value;
      };

      const type = getType(object);

      const declaration = `interface ${name} ${type}`;

      return namespace ? `namespace ${namespace} { \r\n ${declaration} \r\n}` : declaration;
  }

  /**
   * 读取文件并解析成 JSON 对象
   * @param {string} path - 文件路径
   * @returns {Promise<Object>} - JSON 对象
   */
  async function readJson(path) {
      const content = await fs.readFile(path, 'utf8');
      return JSON.parse(content);
  }

  /**
   * 将 TypeScript 类型定义字符串写入文件
   * @param {string} content - TypeScript 类型定义字符串
   * @param {string} path - 文件路径
   * @returns {Promise<void>}
   */
  async function writeTs(content, path) {
      await fs.writeFile(path, content, 'utf8');
  }

  /**
   * 将 JSON 数据转换为 TypeScript 类型定义
   * @param {string} inputPath - 输入 JSON 文件路径
   * @param {string} outputPath - 输出 TypeScript 文件路径
   * @param {string} [options.name=JsonType] - 转换后的类型名称
   * @param {string} [options.namespace] - 转换后的命名空间
   * @param {boolean} [options.noFile] - 不将 TypeScript 类型定义保存为文件
   * @returns {Promise<void>}
   */

  async function jsonToTsFile(inputPath, outputPath, options) {
      const { name, namespace, noFile } = options
      try {
          const object = await readJson(inputPath);
          const type = jsonToTs(object, name, namespace);
          if (noFile) {
              console.log(type);
          } else {
              await writeTs(type, outputPath);
              console.log(`Type definition saved to ${outputPath}`);
          }
      } catch (err) {
          console.error(err.message);
      }
  }

  const program = new commander.Command();

  program
      .arguments('<input> <output>')
      .option('--no-file', 'do not save to file')
      .option('-s, --namespace <namespace>', 'type namespace')
      .option('-n, --name <name>', 'type name', 'JsonType')
      .action(jsonToTsFile);

  program.parse(process.argv);