feat : set second solution

src/10-set.solution.2.ts

@@ -0,0 +1,23 @@
+import { expect, it } from "vitest";
+import { Equal, Expect } from "./helpers/type-utils";
+
+const guitarists: Set<string> = new Set();
+
+guitarists.add("Jimi Hendrix");
+guitarists.add("Eric Clapton");
+
+it("Should contain Jimi and Eric", () => {
+  expect(guitarists.has("Jimi Hendrix")).toEqual(true);
+  expect(guitarists.has("Eric Clapton")).toEqual(true);
+});
+
+it("Should give a type error when you try to pass a non-string", () => {
+  // @ts-expect-error
+  guitarists.add(2);
+});
+
+it("Should be typed as an array of strings", () => {
+  const guitaristsAsArray = Array.from(guitarists);
+
+  type tests = [Expect<Equal<typeof guitaristsAsArray, string[]>>];
+});