Fun with dynamic literals!

plugin.ts

const number = /(?:sbyte|ushort|short|uint|int|ulong|long|float|double|decimal|byte)/;
const string = /(?:char|string)/;
const bool = /(?:bool)/;
const date = /(?:DateTime)/;

let builder = {
  accessModifier: 'public',
  name: 'test',
  type: 'int'
};

let checkObj = {
    [+true]: 'Any',
    [+number.test(builder.type)]: 'number',
    [+string.test(builder.type)]: 'string',
    [+bool.test(builder.type)]: 'boolean',
    [+date.test(builder.type)]: 'moment.Moment',
};

return `${builder.accessModifier} ${builder.name}: ${checkObj[+true]}`;