LibJS: Convert all remaining non-Array tests to the new system :)

Author: https://github.com/mattco98
Commit: 15de2eda2b
Pull-request: https://github.com/SerenityOS/serenity/pull/2689
Reviewed-by: https://github.com/linusg

Libraries/LibJS/Tests/classes/class-methods.js

@@ -0,0 +1,51 @@
+test("basic functionality", () => {
+  class A {
+    number() {
+      return 2;
+    }
+
+    string() {
+      return "foo";
+    }
+  }
+
+  const a = new A();
+  expect(a.number()).toBe(2);
+  expect(a.string()).toBe("foo");
+});
+
+test("length", () => {
+  class A {
+    method1() {}
+
+    method2(a, b, c, d) {}
+
+    method3(a, b, ...c) {}
+  }
+
+  const a = new A();
+  expect(a.method1).toHaveLength(0);
+  expect(a.method2).toHaveLength(4);
+  expect(a.method3).toHaveLength(2);
+});
+
+test("extended name syntax", () => {
+  class A {
+    "method with space"() {
+      return 1;
+    }
+
+    12() {
+      return 2;
+    }
+
+    [`he${"llo"}`]() {
+      return 3;
+    }
+  }
+
+  const a = new A();
+  expect(a["method with space"]()).toBe(1);
+  expect(a[12]()).toBe(2);
+  expect(a.hello()).toBe(3);
+});