LibWeb: Add tests for atob() and btoa()

Author: https://github.com/nico
Commit: https://github.com/SerenityOS/serenity/commit/a92f7aea7a9
Pull-request: https://github.com/SerenityOS/serenity/pull/2864

Libraries/LibWeb/Tests/Document/Doctype.js

@@ -2,10 +2,10 @@ loadPage("file:///res/html/misc/blank.html");
 
 afterPageLoad(() => {
     test("Basic functionality", () => {
-       expect(document.compatMode).toBe("CSS1Compat");
-       expect(document.doctype).toBeDefined();
-       expect(document.doctype.name).toBe("html");
-       expect(document.doctype.publicId).toBe("");
-       expect(document.doctype.systemId).toBe("");
+        expect(document.compatMode).toBe("CSS1Compat");
+        expect(document.doctype).toBeDefined();
+        expect(document.doctype.name).toBe("html");
+        expect(document.doctype.publicId).toBe("");
+        expect(document.doctype.systemId).toBe("");
     });
 });

Libraries/LibWeb/Tests/Window/Base64.js

@@ -0,0 +1,19 @@
+loadPage("file:///res/html/misc/blank.html");
+
+afterPageLoad(() => {
+    test("atob", () => {
+        expect(atob("YQ==")).toBe("a");
+        expect(atob("YWE=")).toBe("aa");
+        expect(atob("YWFh")).toBe("aaa");
+        expect(atob("YWFhYQ==")).toBe("aaaa");
+        expect(atob("/w==")).toBe("\xff");
+    });
+
+    test("btoa", () => {
+        expect(btoa("a")).toBe("YQ==");
+        expect(btoa("aa")).toBe("YWE=");
+        expect(btoa("aaa")).toBe("YWFh");
+        expect(btoa("aaaa")).toBe("YWFhYQ==");
+        expect(btoa("\xff")).toBe("/w==");
+    });
+});