LibJS: Refactor Array.prototype callback functions and make them generic

Libraries/LibJS/Tests/Array.prototype-generic-functions.js

@@ -0,0 +1,47 @@
+load("test-common.js");
+
+try {
+    const o = { length: 5, 0: "foo", 1: "bar", 3: "baz" };
+
+    ["every"].forEach(name => {
+        const visited = [];
+        Array.prototype[name].call(o, function (value) {
+            visited.push(value);
+            return true;
+        });
+        assert(visited.length === 3);
+        assert(visited[0] === "foo");
+        assert(visited[1] === "bar");
+        assert(visited[2] === "baz");
+    });
+
+    ["find", "findIndex"].forEach(name => {
+        const visited = [];
+        Array.prototype[name].call(o, function (value) {
+            visited.push(value);
+            return false;
+        });
+        assert(visited.length === 5);
+        assert(visited[0] === "foo");
+        assert(visited[1] === "bar");
+        assert(visited[2] === undefined);
+        assert(visited[3] === "baz");
+        assert(visited[4] === undefined);
+    });
+
+    ["filter", "forEach", "map", "some"].forEach(name => {
+        const visited = [];
+        Array.prototype[name].call(o, function (value) {
+            visited.push(value);
+            return false;
+        });
+        assert(visited.length === 3);
+        assert(visited[0] === "foo");
+        assert(visited[1] === "bar");
+        assert(visited[2] === "baz");
+    });
+
+    console.log("PASS");
+} catch (e) {
+    console.log("FAIL: " + e);
+}