Dirty way to output types for an object such as a Mongo documents

makeTypes.ts

// This isn't comprehensive and is a pretty dirty hack piece of code,
// but it gets you close when you have a ton of fields in mongo
// collection documents that you need to create interfaces for

function makeTypes(obj: { [key: string]: any }, depth: number = 0) {
  if (obj) {
    let types: string = '';
    Object.keys(obj).forEach((key) => {
      const value = obj[key];
      if (value) {
        if (Array.isArray(value)) {
          const first = value[0];
          if (typeof first === 'string' || typeof first === 'number' || typeof first === 'boolean') {
            types += `${' '.repeat((depth + 1) * 2)}${key}: ${typeof first}[]\n`;
          } else {
            types += `${' '.repeat((depth + 1) * 2)}${key}: ${makeTypes(first, depth + 1)}[]\n`;
          }
        } else if (typeof value === 'object') {
          let typeStr: string;
          if (value instanceof Date) {
            typeStr = 'Date';
          } else {
            typeStr = makeTypes(value, depth + 1);
          }
          types += `${' '.repeat((depth + 1) * 2)}${key}: ${typeStr}\n`;
        } else {
          types += `${' '.repeat((depth + 1) * 2)}${key}: ${typeof value}\n`;
        }
      }
    });

    return `{\n${types}${' '.repeat(depth * 2)}}`;
  }
  return '';
}