LibJS: Implement Set.prototype.intersection

1 files changed, 12 insertions, 0 deletions

diff --git a/Userland/Libraries/LibJS/Tests/builtins/Set/Set.prototype.intersection.js b/Userland/Libraries/LibJS/Tests/builtins/Set/Set.prototype.intersection.js
new file mode 100644
index 0000000000..98ce3f1c96
--- /dev/null
+++ b/Userland/Libraries/LibJS/Tests/builtins/Set/Set.prototype.intersection.js
@@ -0,0 +1,12 @@
+test("basic functionality", () => {
+    expect(Set.prototype.intersection).toHaveLength(1);
+
+    const set1 = new Set(["a", "b", "c"]);
+    const set2 = new Set(["b", "c", "d", "e"]);
+    const intersection1to2 = set1.intersection(set2);
+    const intersection2to1 = set2.intersection(set1);
+    for (const intersectionSet of [intersection1to2, intersection2to1]) {
+        expect(intersectionSet).toHaveSize(2);
+        ["b", "c"].forEach(value => expect(intersectionSet.has(value)).toBeTrue());
+    }
+});