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Cache Add/Get

A cache stores data so that future requests for that data can be served faster. We'll use one to keep PokeAPI responses in memory. No need to make the same network request twice!

First, we need a way to store and retrieve entries. I used a Cache class with a private Map. Each string key identifies a cached value.

The add<T> and get<T> methods use a generic so callers can store different types of data. For example, get<ShallowLocations>(url) returns ShallowLocations | undefined. The caller must use the right type for that key; a type assertion doesn't check the stored value at runtime.

Assignment

Create src/pokecache.ts and export a Cache class. I used a private #cache = new Map<string, unknown>() to hold the values.
Add an add<T>(key: string, val: T) method. Adding an existing key should replace its value.
Add a get<T>(key: string): T | undefined method. Return the stored value when the key exists, or undefined when it doesn't.
Write tests for adding and retrieving entries, missing keys, and replacing a value. Keep different keys in the same cache to check that they don't overwrite each other.

We'll add expiration and connect the cache to the PokeAPI in the next lessons. For now, map and mapb should work as before.

Run and submit the CLI tests from the root of the repo.