Add player leaderboard and homepage preview

tests/leaderboard.test.ts

@@ -0,0 +1,41 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { leaderboardFilters, leaderboardHref } from "../shared/leaderboard";
+
+test("leaderboard filters constrain malformed and repeated query parameters", () => {
+  assert.deepEqual(
+    leaderboardFilters({ difficulty: "hard", q: "  Alex  ", page: "3" }),
+    { difficulty: "hard", search: "Alex", page: 3 },
+  );
+  for (const page of ["-4", "0", "Infinity", "2.5", "no", ["2", "3"]]) {
+    assert.equal(leaderboardFilters({ page }).page, 1);
+  }
+  assert.equal(
+    leaderboardFilters({ difficulty: ["hard", "easy"] }).difficulty,
+    "all",
+  );
+  assert.equal(
+    leaderboardFilters({ difficulty: "creative" }).difficulty,
+    "all",
+  );
+  assert.equal(
+    leaderboardFilters({ q: "x".repeat(100), page: "2000000" }).search.length,
+    64,
+  );
+  assert.equal(leaderboardFilters({ page: "2000000" }).page, 1_000_000);
+});
+
+test("leaderboard navigation preserves and encodes player searches", () => {
+  const link = new URL(
+    leaderboardHref("normal", "Alex & %_", 3),
+    "https://minegeo.test",
+  );
+  assert.equal(link.searchParams.get("difficulty"), "normal");
+  assert.equal(link.searchParams.get("q"), "Alex & %_");
+  assert.equal(link.searchParams.get("page"), "3");
+  assert.equal(leaderboardHref("all"), "/leaderboard");
+  assert.equal(
+    new URL(leaderboardHref("easy", "Alex"), link).searchParams.has("page"),
+    false,
+  );
+});