index.ts

const ANIMALS_KV_KEY_ID = 'all-animals'
export async function getAllAnimals(env: Env): Promise<any[]> {
   let animals = await env.ANIMALS.get(ANIMALS_KV_KEY_ID)

   if (animals === null) {
      return []
   }

   return JSON.parse(animals);
}

export async function updateAnimals(animals: any[], env: Env) {
   await env.ANIMALS.put(ANIMALS_KV_KEY_ID, JSON.stringify(animals))
}

export async function addAnimal(animal: Object, env: Env) {
   let animals = await getAllAnimals(env)

   animals.push(animal);

   await updateAnimals(animals, env)

   return animal;
}