1 files changed, 81 insertions, 53 deletions

diff --git a/Libraries/LibJS/Tests/functions/arrow-functions.js b/Libraries/LibJS/Tests/functions/arrow-functions.js
index 6f9afc632d..3b3ab09ed1 100644
--- a/Libraries/LibJS/Tests/functions/arrow-functions.js
+++ b/Libraries/LibJS/Tests/functions/arrow-functions.js
@@ -1,69 +1,101 @@
-load("test-common.js");
+test("no arguments", () => {
+  let getNumber = () => {
+    return 42;
+  };
+  expect(getNumber()).toBe(42);
 
-try {
-  let getNumber = () => 42;
-  assert(getNumber() === 42);
+  getNumber = () => 42;
+  expect(getNumber()).toBe(42);
 
+  getNumber = () => {
+    return 99;
+  };
+  expect(getNumber()).toBe(99);
   getNumber = () => 99;
-  assert(getNumber() === 99);
+  expect(getNumber()).toBe(99);
+});
 
+test("arguments", () => {
   let add = (a, b) => a + b;
-  assert(add(2, 3) === 5);
+  expect(add(2, 3)).toBe(5);
 
   const addBlock = (a, b) => {
     let res = a + b;
     return res;
   };
-  assert(addBlock(5, 4) === 9);
+  expect(addBlock(5, 4)).toBe(9);
+});
 
+test("inside an array", () => {
   let chompy = [x => x, 2];
-  assert(chompy.length === 2);
-  assert(chompy[0](1) === 1);
+  expect(chompy).toHaveLength(2);
+  expect(chompy[0](1)).toBe(1);
+});
 
+test("return object literal", () => {
   const makeObject = (a, b) => ({ a, b });
   const obj = makeObject(33, 44);
-  assert(typeof obj === "object");
-  assert(obj.a === 33);
-  assert(obj.b === 44);
+  expect(typeof obj).toBe("object");
+  expect(obj.a).toBe(33);
+  expect(obj.b).toBe(44);
+});
 
+test("return undefined", () => {
   let returnUndefined = () => {};
-  assert(typeof returnUndefined() === "undefined");
+  expect(returnUndefined()).toBeUndefined();
+});
 
+test("return array literal", () => {
   const makeArray = (a, b) => [a, b];
   const array = makeArray("3", { foo: 4 });
-  assert(array[0] === "3");
-  assert(array[1].foo === 4);
+  expect(array[0]).toBe("3");
+  expect(array[1].foo).toBe(4);
+});
 
+test("return numeric expression", () => {
   let square = x => x * x;
-  assert(square(3) === 9);
+  expect(square(3)).toBe(9);
 
   let squareBlock = x => {
     return x * x;
   };
-  assert(squareBlock(4) === 16);
+  expect(squareBlock(4)).toBe(16);
+});
 
+test("return called arrow function expression", () => {
   const message = (who => "Hello " + who)("friends!");
-  assert(message === "Hello friends!");
+  expect(message).toBe("Hello friends!");
 
   const sum = ((x, y, z) => x + y + z)(1, 2, 3);
-  assert(sum === 6);
+  expect(sum).toBe(6);
 
   const product = ((x, y, z) => {
     let res = x * y * z;
     return res;
   })(5, 4, 2);
-  assert(product === 40);
+  expect(product).toBe(40);
 
   const half = (x => {
     return x / 2;
   })(10);
-  assert(half === 5);
-
-  var foo, bar;
+  expect(half).toBe(5);
+});
+
+test("currying", () => {
+  let add = a => b => a + b;
+  expect(typeof add(1)).toBe("function");
+  expect(typeof add(1, 2)).toBe("function");
+  expect(add(1)(2)).toBe(3);
+});
+
+test("with comma operator", () => {
+  let foo, bar;
   (foo = bar), baz => {};
-  assert(foo === undefined);
-  assert(bar === undefined);
+  expect(foo).toBe(undefined);
+  expect(bar).toBe(undefined);
+});
 
+test("arrow functions in objects", () => {
   function FooBar() {
     this.x = {
       y: () => this,
@@ -73,50 +105,46 @@ try {
     };
   }
 
-  var foobar = new FooBar();
-  assert(foobar.x.y() === foobar);
-  assert(foobar.x.z() === foobar.x);
-
-  var Baz = () => {};
-
-  assert(Baz.prototype === undefined);
-
-  assertThrowsError(
-    () => {
-      new Baz();
-    },
-    {
-      error: TypeError,
-      message: "Baz is not a constructor",
-    }
-  );
+  const foobar = new FooBar();
+  expect(foobar.x.y()).toBe(foobar);
+  expect(foobar.x.z()).toBe(foobar.x);
+});
 
+test("strict mode propogation", () => {
   (() => {
     "use strict";
-    assert(isStrictMode());
+    expect(isStrictMode()).toBeTrue();
 
     (() => {
-      assert(isStrictMode());
+      expect(isStrictMode()).toBeTrue();
     })();
   })();
 
   (() => {
     "use strict";
-    assert(isStrictMode());
+    expect(isStrictMode()).toBeTrue();
   })();
 
   (() => {
-    assert(!isStrictMode());
+    expect(isStrictMode()).toBeFalse();
 
     (() => {
       "use strict";
-      assert(isStrictMode());
+      expect(isStrictMode()).toBeTrue();
     })();
 
-    assert(!isStrictMode());
+    expect(isStrictMode()).toBeFalse();
   })();
-
-  console.log("PASS");
-} catch {
-  console.log("FAIL");
-}
+});
+
+test("no prototype", () => {
+  let foo = () => {};
+  expect(foo).not.toHaveProperty("prototype");
+});
+
+test("cannot be constructed", () => {
+  let foo = () => {};
+  expect(() => {
+    new foo();
+  }).toThrowWithMessage(TypeError, "foo is not a constructor");
+});