A better stack for your Firebase Rules - Targaryen tests

tests.json

{
  "root": {
    "users": {
      "RICK": {
        "displayName": "Rick Sanchez",
        "age": 60
      },
      "MORTY": {
        "displayName": "Morty Smith",
        "age": 14
      }
    }
  },
  "users": {
    "Rick": { "uid": "RICK" },
    "Morty": { "uid": "MORTY" },
    "Server": { "uid": "SERVER" }
  },
  "tests": {
    "users": {
      "canRead": ["Server"],
      "cannotRead": ["Rick", "Morty"]
    },
    "users/MORTY": {
      "canRead": ["Server", "Morty"],
      "cannotRead": ["Rick"]
    },
    "users/RICK/age": {
      "canWrite": [{ "auth": "Rick", "data": 59 }]
    },
    "users/RICK/displayName": {
      "canWrite": [{ "auth": "Rick", "data": "Pickle Rick" }],
      "cannotWrite": [
        { "auth": "Rick", "data": null },
        { "auth": "Rick", "data": 123 },
        { "auth": "Rick", "data": { "no": "object" } }
      ]
    }
  }
}