import { assertEquals } from "@std/assert";
import { FakeTime } from "@std/testing/time";
import { TtlCache } from "../../lib/ttl-cache.ts";

Deno.test("TtlCache: an entry expires ttlMs after it is written", () => {
  using time = new FakeTime();
  const cache = new TtlCache<string>(1000, 10);
  cache.set("a", "x");
  time.tick(999);
  assertEquals(cache.get("a"), "x");
  time.tick(1);
  assertEquals(cache.get("a"), undefined);
});

Deno.test("TtlCache: past maxEntries, the oldest write goes first", () => {
  const cache = new TtlCache<number>(1000, 2);
  cache.set("a", 1);
  cache.set("b", 2);
  // Rewriting "a" makes it the newest, so "b" is the oldest now.
  cache.set("a", 3);
  cache.set("c", 4);
  assertEquals(cache.get("a"), 3);
  assertEquals(cache.get("b"), undefined);
  assertEquals(cache.get("c"), 4);
});

Deno.test("TtlCache: delete with a value spares a newer entry", () => {
  const cache = new TtlCache<object>(1000, 10);
  const first = {};
  const second = {};
  cache.set("k", first);
  cache.set("k", second);
  cache.delete("k", first);
  assertEquals(cache.get("k"), second);
  cache.delete("k", second);
  assertEquals(cache.get("k"), undefined);
});