LibJS: Add tests for bitwise NOT operator

Author: https://github.com/linusg
Commit: https://github.com/SerenityOS/serenity/commit/7b2fdd08cec
Pull-request: https://github.com/SerenityOS/serenity/pull/4869

Libraries/LibJS/Tests/operators/bitwise-not.js

@@ -0,0 +1,23 @@
+test("basic functionality", () => {
+    expect(~0).toBe(-1);
+    expect(~1).toBe(-2);
+    expect(~2).toBe(-3);
+    expect(~3).toBe(-4);
+    expect(~4).toBe(-5);
+    expect(~5).toBe(-6);
+    expect(~-1).toBe(0);
+    expect(~42).toBe(-43);
+    expect(~9999).toBe(-10000);
+});
+
+test("non-numeric values", () => {
+    expect(~"42").toBe(-43);
+    expect(~"foo").toBe(-1);
+    expect(~[]).toBe(-1);
+    expect(~{}).toBe(-1);
+    expect(~undefined).toBe(-1);
+    expect(~null).toBe(-1);
+    expect(~NaN).toBe(-1);
+    expect(~Infinity).toBe(-1);
+    expect(~-Infinity).toBe(-1);
+});