Delete parser and iterator

lib/binding_web/test/language-test.js

@@ -51,14 +51,19 @@ describe("Lookahead iterator", () => {
     ({ JavaScript, Parser } = await require("./helper"));
     const parser = new Parser().setLanguage(JavaScript);
     const tree = parser.parse("function fn() {}");
+    parser.delete();
     const cursor = tree.walk();
-    cursor.gotoFirstChild();
-    cursor.gotoFirstChild();
+    assert(cursor.gotoFirstChild());
+    assert(cursor.gotoFirstChild());
     state = cursor.currentNode().nextParseState;
     lookahead = JavaScript.lookaheadIterator(state);
     assert.exists(lookahead);
   });
 
+  after(() => {
+    lookahead.delete();
+  });
+
   const expected = ["identifier", "comment", "(", "*", "formal_parameters"];
   it("should iterate over valid symbols in the state", () => {
     const symbols = Array.from(lookahead);