fixtures.js

// Type Definitions

type UserListing = {
  users: Array<User>
}

type ProfilePic = {
  url: string,
  width: number,
  height: number
}

type Role = "Administrator" | "Editor" | "Reader";
type Administrator = "Administrator";

type User = {
  id: number,
  firstName: string,
  lastName: string,
  role: Role,
  activated: bool,
  profilePic: ProfilePic
}

// Usage

import {UserListing} from "./types";
import {gen, genN} from "flow-runtime";

gen(UserListing);

// Output

{
  "users": [
    {
      "id": 1,
      "firstName": "String",
      "lastName": "String",
      "role": "Administrator",
      "activated": true,
      "profilePic": {
        "url": "String",
        "width": 1,
        "height": 1
      }
    }
  ]
}