我正在尝试让Handlebars JS显示一个Typescript Map的内容，其中键是字符串，值是对象。为什么下面的代码和模板不工作？代码生成索引号作为键（当它应该是字符串键）和空值。我如何修复它？

import * as fs from 'fs';
import Handlebars from 'handlebars';

function main() {
  let template;
  try {
    const content = fs.readFileSync('template.hbs').toString();
    template = Handlebars.compile(content);
  }
  catch (e) {
  }

  let map = new Map<string, object>();
  map.set("color1", { type: "red"});
  map.set("color2", { type: "green"});
  map.set("color3", { type: "blue"});

  console.log("JSON");
  let json = template({map}, { strict: true });
  console.log(json);
}

main();

和template.hbs

{
    "colors": {
    {{#each map}}
    "{{@key}}": {
        "type": "{{type}}"
    },
    {{/each}}
    }
}

输出为：

JSON
{"colors": {
    "0": {
        "type": ""
    },
    "1": {
        "type": ""
    },
    "2": {
        "type": ""
    },
}
}