diff --git a/Libraries/LibJS/Tests/Array.js b/Libraries/LibJS/Tests/Array.js
index 519bb54d8b..122f1501a7 100644
--- a/Libraries/LibJS/Tests/Array.js
+++ b/Libraries/LibJS/Tests/Array.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Array.length === 1);
     assert(Array.prototype.length === 0);
diff --git a/Libraries/LibJS/Tests/Array.prototype.pop.js b/Libraries/LibJS/Tests/Array.prototype.pop.js
index c6ce64554b..9dce8d4c29 100644
--- a/Libraries/LibJS/Tests/Array.prototype.pop.js
+++ b/Libraries/LibJS/Tests/Array.prototype.pop.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var a = [1, 2, 3];
     var value = a.pop();
diff --git a/Libraries/LibJS/Tests/Array.prototype.shift.js b/Libraries/LibJS/Tests/Array.prototype.shift.js
index 97f748744b..44cb316203 100644
--- a/Libraries/LibJS/Tests/Array.prototype.shift.js
+++ b/Libraries/LibJS/Tests/Array.prototype.shift.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var a = [1, 2, 3];
     var value = a.shift();
diff --git a/Libraries/LibJS/Tests/Array.prototype.toString.js b/Libraries/LibJS/Tests/Array.prototype.toString.js
index afffee48ad..3bd288f99a 100644
--- a/Libraries/LibJS/Tests/Array.prototype.toString.js
+++ b/Libraries/LibJS/Tests/Array.prototype.toString.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var a = [1, 2, 3];
     assert(a.toString() === '1,2,3');
diff --git a/Libraries/LibJS/Tests/Boolean.js b/Libraries/LibJS/Tests/Boolean.js
index 1a9f8593f1..c77bc04f39 100644
--- a/Libraries/LibJS/Tests/Boolean.js
+++ b/Libraries/LibJS/Tests/Boolean.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Boolean.length === 1);
     assert(typeof new Boolean() === "object");
diff --git a/Libraries/LibJS/Tests/Boolean.prototype.js b/Libraries/LibJS/Tests/Boolean.prototype.js
index de444128c3..31cb114a82 100644
--- a/Libraries/LibJS/Tests/Boolean.prototype.js
+++ b/Libraries/LibJS/Tests/Boolean.prototype.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(typeof Boolean.prototype === "object");
     assert(Boolean.prototype.valueOf() === false);
diff --git a/Libraries/LibJS/Tests/Boolean.prototype.toString.js b/Libraries/LibJS/Tests/Boolean.prototype.toString.js
index 9a8846af4b..843dbec593 100644
--- a/Libraries/LibJS/Tests/Boolean.prototype.toString.js
+++ b/Libraries/LibJS/Tests/Boolean.prototype.toString.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var foo = true;
     assert(foo.toString() === "true");
diff --git a/Libraries/LibJS/Tests/Boolean.prototype.valueOf.js b/Libraries/LibJS/Tests/Boolean.prototype.valueOf.js
index 7cfba10495..21ba4df190 100644
--- a/Libraries/LibJS/Tests/Boolean.prototype.valueOf.js
+++ b/Libraries/LibJS/Tests/Boolean.prototype.valueOf.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var foo = true;
     assert(foo.valueOf() === true);
diff --git a/Libraries/LibJS/Tests/Date.now.js b/Libraries/LibJS/Tests/Date.now.js
index 5459242cd4..72c5cc7930 100644
--- a/Libraries/LibJS/Tests/Date.now.js
+++ b/Libraries/LibJS/Tests/Date.now.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var last = 0;
     for (var i = 0; i < 100; ++i) {
diff --git a/Libraries/LibJS/Tests/Date.prototype.getDate.js b/Libraries/LibJS/Tests/Date.prototype.getDate.js
index e70dc7623c..4ad6a3b390 100644
--- a/Libraries/LibJS/Tests/Date.prototype.getDate.js
+++ b/Libraries/LibJS/Tests/Date.prototype.getDate.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var d = new Date();
     assert(!isNaN(d.getDate()));
diff --git a/Libraries/LibJS/Tests/Date.prototype.getDay.js b/Libraries/LibJS/Tests/Date.prototype.getDay.js
index 631f386ae3..94dbe1622b 100644
--- a/Libraries/LibJS/Tests/Date.prototype.getDay.js
+++ b/Libraries/LibJS/Tests/Date.prototype.getDay.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var d = new Date();
     assert(!isNaN(d.getDay()));
diff --git a/Libraries/LibJS/Tests/Date.prototype.getFullYear.js b/Libraries/LibJS/Tests/Date.prototype.getFullYear.js
index 6a102f2395..44416882c9 100644
--- a/Libraries/LibJS/Tests/Date.prototype.getFullYear.js
+++ b/Libraries/LibJS/Tests/Date.prototype.getFullYear.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var d = new Date();
     assert(!isNaN(d.getFullYear()));
diff --git a/Libraries/LibJS/Tests/Date.prototype.getHours.js b/Libraries/LibJS/Tests/Date.prototype.getHours.js
index b09e000a6e..2e7984b497 100644
--- a/Libraries/LibJS/Tests/Date.prototype.getHours.js
+++ b/Libraries/LibJS/Tests/Date.prototype.getHours.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var d = new Date();
     assert(!isNaN(d.getHours()));
diff --git a/Libraries/LibJS/Tests/Date.prototype.getMilliseconds.js b/Libraries/LibJS/Tests/Date.prototype.getMilliseconds.js
index 95f9d19916..49ef970fe8 100644
--- a/Libraries/LibJS/Tests/Date.prototype.getMilliseconds.js
+++ b/Libraries/LibJS/Tests/Date.prototype.getMilliseconds.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var d = new Date();
     assert(!isNaN(d.getMilliseconds()));
diff --git a/Libraries/LibJS/Tests/Date.prototype.getMinutes.js b/Libraries/LibJS/Tests/Date.prototype.getMinutes.js
index bf09c0278e..380f864ed4 100644
--- a/Libraries/LibJS/Tests/Date.prototype.getMinutes.js
+++ b/Libraries/LibJS/Tests/Date.prototype.getMinutes.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var d = new Date();
     assert(!isNaN(d.getMinutes()));
diff --git a/Libraries/LibJS/Tests/Date.prototype.getMonth.js b/Libraries/LibJS/Tests/Date.prototype.getMonth.js
index a6503b9b32..3556770058 100644
--- a/Libraries/LibJS/Tests/Date.prototype.getMonth.js
+++ b/Libraries/LibJS/Tests/Date.prototype.getMonth.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var d = new Date();
     assert(!isNaN(d.getMonth()));
diff --git a/Libraries/LibJS/Tests/Date.prototype.getSeconds.js b/Libraries/LibJS/Tests/Date.prototype.getSeconds.js
index e96272f9d6..7247bc9f13 100644
--- a/Libraries/LibJS/Tests/Date.prototype.getSeconds.js
+++ b/Libraries/LibJS/Tests/Date.prototype.getSeconds.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var d = new Date();
     assert(!isNaN(d.getSeconds()));
diff --git a/Libraries/LibJS/Tests/Date.prototype.getTime.js b/Libraries/LibJS/Tests/Date.prototype.getTime.js
index a7a54ee3fc..8c352465fe 100644
--- a/Libraries/LibJS/Tests/Date.prototype.getTime.js
+++ b/Libraries/LibJS/Tests/Date.prototype.getTime.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var d = new Date();
     assert(!isNaN(d.getTime()));
diff --git a/Libraries/LibJS/Tests/Error.js b/Libraries/LibJS/Tests/Error.js
index ddf78f28a9..0338dded12 100644
--- a/Libraries/LibJS/Tests/Error.js
+++ b/Libraries/LibJS/Tests/Error.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var e;
 
diff --git a/Libraries/LibJS/Tests/Error.prototype.name.js b/Libraries/LibJS/Tests/Error.prototype.name.js
index 991cb92aee..48123543df 100644
--- a/Libraries/LibJS/Tests/Error.prototype.name.js
+++ b/Libraries/LibJS/Tests/Error.prototype.name.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var changedInstance = new Error("");
     changedInstance.name = 'NewCustomError';
diff --git a/Libraries/LibJS/Tests/Error.prototype.toString.js b/Libraries/LibJS/Tests/Error.prototype.toString.js
index 88a785fc23..e4f1d7db1e 100644
--- a/Libraries/LibJS/Tests/Error.prototype.toString.js
+++ b/Libraries/LibJS/Tests/Error.prototype.toString.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Error().toString() === "Error");
     assert(Error(undefined).toString() === "Error");
diff --git a/Libraries/LibJS/Tests/Function.js b/Libraries/LibJS/Tests/Function.js
index 1f4b232b6b..b832f27798 100644
--- a/Libraries/LibJS/Tests/Function.js
+++ b/Libraries/LibJS/Tests/Function.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Function.length === 1);
     assert(Function.prototype.length === 0);
diff --git a/Libraries/LibJS/Tests/Function.prototype.apply.js b/Libraries/LibJS/Tests/Function.prototype.apply.js
index 04f2fbd71b..f3e20d3fb2 100644
--- a/Libraries/LibJS/Tests/Function.prototype.apply.js
+++ b/Libraries/LibJS/Tests/Function.prototype.apply.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     function Foo(arg) {
         this.foo = arg;
diff --git a/Libraries/LibJS/Tests/Function.prototype.call.js b/Libraries/LibJS/Tests/Function.prototype.call.js
index 30e7725896..29eb153ea5 100644
--- a/Libraries/LibJS/Tests/Function.prototype.call.js
+++ b/Libraries/LibJS/Tests/Function.prototype.call.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     function Foo(arg) {
         this.foo = arg;
diff --git a/Libraries/LibJS/Tests/Function.prototype.toString.js b/Libraries/LibJS/Tests/Function.prototype.toString.js
index 231a49458d..4f2e1cf5e6 100644
--- a/Libraries/LibJS/Tests/Function.prototype.toString.js
+++ b/Libraries/LibJS/Tests/Function.prototype.toString.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert((function() {}).toString() === "function () {\n  ???\n}");
     assert((function(foo) {}).toString() === "function (foo) {\n  ???\n}");
diff --git a/Libraries/LibJS/Tests/Infinity-basic.js b/Libraries/LibJS/Tests/Infinity-basic.js
index 33164410f4..9bab327822 100644
--- a/Libraries/LibJS/Tests/Infinity-basic.js
+++ b/Libraries/LibJS/Tests/Infinity-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Infinity + "" === "Infinity");
     assert(-Infinity + "" === "-Infinity");
diff --git a/Libraries/LibJS/Tests/Math-constants.js b/Libraries/LibJS/Tests/Math-constants.js
index 0c402ddf93..9fe84c4bee 100644
--- a/Libraries/LibJS/Tests/Math-constants.js
+++ b/Libraries/LibJS/Tests/Math-constants.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 // Borrowed from LibM/TestMath.cpp :^)
 function expectClose(a, b) { assert(Math.abs(a - b) < 0.000001); }
 
diff --git a/Libraries/LibJS/Tests/Math.abs.js b/Libraries/LibJS/Tests/Math.abs.js
index 0c2ed1e0ab..583af24dfa 100644
--- a/Libraries/LibJS/Tests/Math.abs.js
+++ b/Libraries/LibJS/Tests/Math.abs.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Math.abs('-1') === 1);
     assert(Math.abs(-2) === 2);
diff --git a/Libraries/LibJS/Tests/Math.ceil.js b/Libraries/LibJS/Tests/Math.ceil.js
index 9ed8ff8960..56a6ff6269 100644
--- a/Libraries/LibJS/Tests/Math.ceil.js
+++ b/Libraries/LibJS/Tests/Math.ceil.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Math.ceil(0.95) === 1);
     assert(Math.ceil(4) === 4);
diff --git a/Libraries/LibJS/Tests/Math.cos.js b/Libraries/LibJS/Tests/Math.cos.js
index 2af3d7dbb8..e483243ae4 100644
--- a/Libraries/LibJS/Tests/Math.cos.js
+++ b/Libraries/LibJS/Tests/Math.cos.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Math.cos(0) === 1);
     assert(Math.cos(null) === 1);
diff --git a/Libraries/LibJS/Tests/Math.max.js b/Libraries/LibJS/Tests/Math.max.js
index 2b4a814a9f..7b01e44102 100644
--- a/Libraries/LibJS/Tests/Math.max.js
+++ b/Libraries/LibJS/Tests/Math.max.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Math.max.length === 2);
     assert(Math.max() === -Infinity);
diff --git a/Libraries/LibJS/Tests/Math.min.js b/Libraries/LibJS/Tests/Math.min.js
index 35b8746ee6..fbe26bd27b 100644
--- a/Libraries/LibJS/Tests/Math.min.js
+++ b/Libraries/LibJS/Tests/Math.min.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Math.min.length === 2);
     assert(Math.min(1) === 1);
diff --git a/Libraries/LibJS/Tests/Math.sin.js b/Libraries/LibJS/Tests/Math.sin.js
index bd93e66890..50a591b1c9 100644
--- a/Libraries/LibJS/Tests/Math.sin.js
+++ b/Libraries/LibJS/Tests/Math.sin.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Math.sin(0) === 0);
     assert(Math.sin(null) === 0);
diff --git a/Libraries/LibJS/Tests/Math.sqrt.js b/Libraries/LibJS/Tests/Math.sqrt.js
index 07a57e6507..622fd8b198 100644
--- a/Libraries/LibJS/Tests/Math.sqrt.js
+++ b/Libraries/LibJS/Tests/Math.sqrt.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Math.sqrt(9) === 3);
     console.log("PASS");
diff --git a/Libraries/LibJS/Tests/Math.tan.js b/Libraries/LibJS/Tests/Math.tan.js
index 07b9ff73f4..636fe2add7 100644
--- a/Libraries/LibJS/Tests/Math.tan.js
+++ b/Libraries/LibJS/Tests/Math.tan.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Math.tan(0) === 0);
     assert(Math.tan(null) === 0);
diff --git a/Libraries/LibJS/Tests/Math.trunc.js b/Libraries/LibJS/Tests/Math.trunc.js
index ec2bf0c537..79b257b176 100644
--- a/Libraries/LibJS/Tests/Math.trunc.js
+++ b/Libraries/LibJS/Tests/Math.trunc.js
@@ -1,3 +1,5 @@
+load("test-common.js")
+
 try {
     assert(Math.trunc(13.37) === 13);
     assert(Math.trunc(42.84) === 42);
diff --git a/Libraries/LibJS/Tests/NaN-basic.js b/Libraries/LibJS/Tests/NaN-basic.js
index 17b51711d6..188d9347e3 100644
--- a/Libraries/LibJS/Tests/NaN-basic.js
+++ b/Libraries/LibJS/Tests/NaN-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var nan = undefined + 1;
     assert(nan + "" == "NaN");
diff --git a/Libraries/LibJS/Tests/Number-constants.js b/Libraries/LibJS/Tests/Number-constants.js
index 7d52bce470..ce2e7a67f9 100644
--- a/Libraries/LibJS/Tests/Number-constants.js
+++ b/Libraries/LibJS/Tests/Number-constants.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Number.EPSILON === 2 ** -52);
     assert(Number.EPSILON > 0);
diff --git a/Libraries/LibJS/Tests/Number.isSafeInteger.js b/Libraries/LibJS/Tests/Number.isSafeInteger.js
index ee7e2308e7..407b999d9a 100644
--- a/Libraries/LibJS/Tests/Number.isSafeInteger.js
+++ b/Libraries/LibJS/Tests/Number.isSafeInteger.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Number.isSafeInteger.length === 1);
     assert(Number.isSafeInteger(0) === true);
diff --git a/Libraries/LibJS/Tests/Number.js b/Libraries/LibJS/Tests/Number.js
index 10a110840f..ba16723525 100644
--- a/Libraries/LibJS/Tests/Number.js
+++ b/Libraries/LibJS/Tests/Number.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Number.length === 1);
     assert(typeof Number() === "number");
diff --git a/Libraries/LibJS/Tests/Number.prototype.js b/Libraries/LibJS/Tests/Number.prototype.js
index 1ff4705fc0..f42f913fba 100644
--- a/Libraries/LibJS/Tests/Number.prototype.js
+++ b/Libraries/LibJS/Tests/Number.prototype.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
   assert(typeof Number.prototype === "object");
   assert(Number.prototype.valueOf() === 0);
diff --git a/Libraries/LibJS/Tests/Object.defineProperty.js b/Libraries/LibJS/Tests/Object.defineProperty.js
index d63e89beb2..fee37f9e78 100644
--- a/Libraries/LibJS/Tests/Object.defineProperty.js
+++ b/Libraries/LibJS/Tests/Object.defineProperty.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var o = {};
     Object.defineProperty(o, "foo", { value: 1, writable: false, enumerable: false });
diff --git a/Libraries/LibJS/Tests/Object.getOwnPropertyNames.js b/Libraries/LibJS/Tests/Object.getOwnPropertyNames.js
index 990dbf2801..cbb90108fc 100644
--- a/Libraries/LibJS/Tests/Object.getOwnPropertyNames.js
+++ b/Libraries/LibJS/Tests/Object.getOwnPropertyNames.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var names = Object.getOwnPropertyNames([1, 2, 3]);
 
diff --git a/Libraries/LibJS/Tests/Object.getPrototypeOf.js b/Libraries/LibJS/Tests/Object.getPrototypeOf.js
index 08ccc6a0da..3e35fcb797 100644
--- a/Libraries/LibJS/Tests/Object.getPrototypeOf.js
+++ b/Libraries/LibJS/Tests/Object.getPrototypeOf.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var o1 = new Object();
     var o2 = {};
diff --git a/Libraries/LibJS/Tests/Object.prototype.constructor.js b/Libraries/LibJS/Tests/Object.prototype.constructor.js
index 9f9218fd6d..06f5921bf8 100644
--- a/Libraries/LibJS/Tests/Object.prototype.constructor.js
+++ b/Libraries/LibJS/Tests/Object.prototype.constructor.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(Array.prototype.constructor === Array)
     assert(Boolean.prototype.constructor === Boolean)
diff --git a/Libraries/LibJS/Tests/Object.prototype.hasOwnProperty.js b/Libraries/LibJS/Tests/Object.prototype.hasOwnProperty.js
index 225394939f..0a12f2ee52 100644
--- a/Libraries/LibJS/Tests/Object.prototype.hasOwnProperty.js
+++ b/Libraries/LibJS/Tests/Object.prototype.hasOwnProperty.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var o = {};
     o.foo = 1;
diff --git a/Libraries/LibJS/Tests/Object.prototype.js b/Libraries/LibJS/Tests/Object.prototype.js
index 0d794442d5..549716bb65 100644
--- a/Libraries/LibJS/Tests/Object.prototype.js
+++ b/Libraries/LibJS/Tests/Object.prototype.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var o = new Object();
     Object.prototype.foo = 123;
diff --git a/Libraries/LibJS/Tests/Object.prototype.toString.js b/Libraries/LibJS/Tests/Object.prototype.toString.js
index 2672b70f1b..94b9c1f2b2 100644
--- a/Libraries/LibJS/Tests/Object.prototype.toString.js
+++ b/Libraries/LibJS/Tests/Object.prototype.toString.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(typeof Object.prototype.toString() === "string");
     console.log("PASS");
diff --git a/Libraries/LibJS/Tests/String.prototype.charAt.js b/Libraries/LibJS/Tests/String.prototype.charAt.js
index 994fed659d..9e9fbd96b4 100644
--- a/Libraries/LibJS/Tests/String.prototype.charAt.js
+++ b/Libraries/LibJS/Tests/String.prototype.charAt.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var s = "foobar"
     assert(typeof s === "string");
diff --git a/Libraries/LibJS/Tests/String.prototype.indexOf.js b/Libraries/LibJS/Tests/String.prototype.indexOf.js
index 117093b61e..b0488e955c 100644
--- a/Libraries/LibJS/Tests/String.prototype.indexOf.js
+++ b/Libraries/LibJS/Tests/String.prototype.indexOf.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var s = "hello friends"
 
diff --git a/Libraries/LibJS/Tests/String.prototype.js b/Libraries/LibJS/Tests/String.prototype.js
index 4bc304babf..a3b0228224 100644
--- a/Libraries/LibJS/Tests/String.prototype.js
+++ b/Libraries/LibJS/Tests/String.prototype.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(typeof Object.getPrototypeOf("") === "object");
     assert(Object.getPrototypeOf("").valueOf() === '');
diff --git a/Libraries/LibJS/Tests/String.prototype.padEnd.js b/Libraries/LibJS/Tests/String.prototype.padEnd.js
index a654ec8b46..18ea5377cd 100644
--- a/Libraries/LibJS/Tests/String.prototype.padEnd.js
+++ b/Libraries/LibJS/Tests/String.prototype.padEnd.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(String.prototype.padEnd.length === 1);
 
diff --git a/Libraries/LibJS/Tests/String.prototype.padStart.js b/Libraries/LibJS/Tests/String.prototype.padStart.js
index 322d1c7a35..0b2b99d803 100644
--- a/Libraries/LibJS/Tests/String.prototype.padStart.js
+++ b/Libraries/LibJS/Tests/String.prototype.padStart.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(String.prototype.padStart.length === 1);
 
diff --git a/Libraries/LibJS/Tests/String.prototype.startsWith.js b/Libraries/LibJS/Tests/String.prototype.startsWith.js
index fe7c511681..2ed6d486f5 100644
--- a/Libraries/LibJS/Tests/String.prototype.startsWith.js
+++ b/Libraries/LibJS/Tests/String.prototype.startsWith.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var s = "foobar";
     assert(s.startsWith("f") === true);
diff --git a/Libraries/LibJS/Tests/String.prototype.toLowerCase.js b/Libraries/LibJS/Tests/String.prototype.toLowerCase.js
index a1f6b58993..571f26e729 100644
--- a/Libraries/LibJS/Tests/String.prototype.toLowerCase.js
+++ b/Libraries/LibJS/Tests/String.prototype.toLowerCase.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(String.prototype.toLowerCase.length === 0);
 
diff --git a/Libraries/LibJS/Tests/String.prototype.toString.js b/Libraries/LibJS/Tests/String.prototype.toString.js
index ffb25c758b..3be304ed1e 100644
--- a/Libraries/LibJS/Tests/String.prototype.toString.js
+++ b/Libraries/LibJS/Tests/String.prototype.toString.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(String.prototype.toString.length === 0)
     assert("".toString() === "");
diff --git a/Libraries/LibJS/Tests/String.prototype.toUpperCase.js b/Libraries/LibJS/Tests/String.prototype.toUpperCase.js
index 2a68e1e770..c1532dfa22 100644
--- a/Libraries/LibJS/Tests/String.prototype.toUpperCase.js
+++ b/Libraries/LibJS/Tests/String.prototype.toUpperCase.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(String.prototype.toUpperCase.length === 0);
 
diff --git a/Libraries/LibJS/Tests/array-basic.js b/Libraries/LibJS/Tests/array-basic.js
index 7298fab672..bfd1064da7 100644
--- a/Libraries/LibJS/Tests/array-basic.js
+++ b/Libraries/LibJS/Tests/array-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var a = [1, 2, 3];
 
diff --git a/Libraries/LibJS/Tests/arrow-functions.js b/Libraries/LibJS/Tests/arrow-functions.js
index d2db8fdaf5..56537de34c 100644
--- a/Libraries/LibJS/Tests/arrow-functions.js
+++ b/Libraries/LibJS/Tests/arrow-functions.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     let getNumber = () => 42;
     assert(getNumber() === 42);
diff --git a/Libraries/LibJS/Tests/binary-bitwise-operators-basic.js b/Libraries/LibJS/Tests/binary-bitwise-operators-basic.js
index 704a00349e..09eb1ae036 100644
--- a/Libraries/LibJS/Tests/binary-bitwise-operators-basic.js
+++ b/Libraries/LibJS/Tests/binary-bitwise-operators-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert((0 | 0) === 0);
     assert((0 | 1) === 1);
diff --git a/Libraries/LibJS/Tests/continue-basic.js b/Libraries/LibJS/Tests/continue-basic.js
index a0d59cdeb6..28d2cfa588 100644
--- a/Libraries/LibJS/Tests/continue-basic.js
+++ b/Libraries/LibJS/Tests/continue-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var j = 0;
     for (var i = 0; i < 9; ++i) {
diff --git a/Libraries/LibJS/Tests/do-while-basic.js b/Libraries/LibJS/Tests/do-while-basic.js
index 5ca6d50791..9472ec4808 100644
--- a/Libraries/LibJS/Tests/do-while-basic.js
+++ b/Libraries/LibJS/Tests/do-while-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var number = 0;
     do {
diff --git a/Libraries/LibJS/Tests/exception-ReferenceError.js b/Libraries/LibJS/Tests/exception-ReferenceError.js
index b26804a316..1bbf506bdc 100644
--- a/Libraries/LibJS/Tests/exception-ReferenceError.js
+++ b/Libraries/LibJS/Tests/exception-ReferenceError.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     i < 3;
 } catch (e) {
diff --git a/Libraries/LibJS/Tests/exponentiation-basic.js b/Libraries/LibJS/Tests/exponentiation-basic.js
index 8e7c7c74f2..0684c46889 100644
--- a/Libraries/LibJS/Tests/exponentiation-basic.js
+++ b/Libraries/LibJS/Tests/exponentiation-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(2 ** 0 === 1);
     assert(2 ** 1 === 2);
diff --git a/Libraries/LibJS/Tests/for-basic.js b/Libraries/LibJS/Tests/for-basic.js
index c68c2b9972..747a574cb1 100644
--- a/Libraries/LibJS/Tests/for-basic.js
+++ b/Libraries/LibJS/Tests/for-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var a = [];
     for (var i = 0; i < 3; ++i) {
diff --git a/Libraries/LibJS/Tests/for-no-curlies.js b/Libraries/LibJS/Tests/for-no-curlies.js
index 8c54819a2d..6b808dad91 100644
--- a/Libraries/LibJS/Tests/for-no-curlies.js
+++ b/Libraries/LibJS/Tests/for-no-curlies.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var number = 0;
 
diff --git a/Libraries/LibJS/Tests/function-TypeError.js b/Libraries/LibJS/Tests/function-TypeError.js
index cd7870c952..8d63265f49 100644
--- a/Libraries/LibJS/Tests/function-TypeError.js
+++ b/Libraries/LibJS/Tests/function-TypeError.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     try {
         var b = true;
diff --git a/Libraries/LibJS/Tests/function-length.js b/Libraries/LibJS/Tests/function-length.js
index 7a3e69cc32..05cfc2a66a 100644
--- a/Libraries/LibJS/Tests/function-length.js
+++ b/Libraries/LibJS/Tests/function-length.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     function foo() { }
     assert(foo.length === 0);
diff --git a/Libraries/LibJS/Tests/function-missing-arg.js b/Libraries/LibJS/Tests/function-missing-arg.js
index 48810a38e7..39c10b6649 100644
--- a/Libraries/LibJS/Tests/function-missing-arg.js
+++ b/Libraries/LibJS/Tests/function-missing-arg.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 function foo(a, b) { return a + b; }
 
 try {
diff --git a/Libraries/LibJS/Tests/function-this-in-arguments.js b/Libraries/LibJS/Tests/function-this-in-arguments.js
index 0bfa3de834..4fb2a3248f 100644
--- a/Libraries/LibJS/Tests/function-this-in-arguments.js
+++ b/Libraries/LibJS/Tests/function-this-in-arguments.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
   assert(typeof this === "object");
   assert(this === globalThis);
diff --git a/Libraries/LibJS/Tests/instanceof-basic.js b/Libraries/LibJS/Tests/instanceof-basic.js
index 0db8dbdc0a..29d22e7e60 100644
--- a/Libraries/LibJS/Tests/instanceof-basic.js
+++ b/Libraries/LibJS/Tests/instanceof-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     function Foo() {
         this.x = 123;
diff --git a/Libraries/LibJS/Tests/invalid-lhs-in-assignment.js b/Libraries/LibJS/Tests/invalid-lhs-in-assignment.js
index 323ed9bb66..d7f65af2c0 100644
--- a/Libraries/LibJS/Tests/invalid-lhs-in-assignment.js
+++ b/Libraries/LibJS/Tests/invalid-lhs-in-assignment.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     try {
         Math.abs(-20) = 40;
diff --git a/Libraries/LibJS/Tests/let-scoping.js b/Libraries/LibJS/Tests/let-scoping.js
index 8bdeb9f04b..a47c2bb202 100644
--- a/Libraries/LibJS/Tests/let-scoping.js
+++ b/Libraries/LibJS/Tests/let-scoping.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
 
     let i = 1;
diff --git a/Libraries/LibJS/Tests/logical-expressions-basic.js b/Libraries/LibJS/Tests/logical-expressions-basic.js
index de7ff65fd7..b02eb6fcdd 100644
--- a/Libraries/LibJS/Tests/logical-expressions-basic.js
+++ b/Libraries/LibJS/Tests/logical-expressions-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert((true && true) === true);
     assert((false && false) === false);
diff --git a/Libraries/LibJS/Tests/logical-expressions-short-circuit.js b/Libraries/LibJS/Tests/logical-expressions-short-circuit.js
index a666255ac7..77edd59b80 100644
--- a/Libraries/LibJS/Tests/logical-expressions-short-circuit.js
+++ b/Libraries/LibJS/Tests/logical-expressions-short-circuit.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     let foo = 1;
     false && (foo = 2);
diff --git a/Libraries/LibJS/Tests/modulo-basic.js b/Libraries/LibJS/Tests/modulo-basic.js
index e5b74d60e2..c8e9a22fb0 100644
--- a/Libraries/LibJS/Tests/modulo-basic.js
+++ b/Libraries/LibJS/Tests/modulo-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(10 % 3 === 1);
     assert(10.5 % 2.5 === 0.5);
diff --git a/Libraries/LibJS/Tests/numeric-literals-basic.js b/Libraries/LibJS/Tests/numeric-literals-basic.js
index 3cf308d2ce..0b1f6249d6 100644
--- a/Libraries/LibJS/Tests/numeric-literals-basic.js
+++ b/Libraries/LibJS/Tests/numeric-literals-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(0xff === 255);
     assert(0XFF === 255);
diff --git a/Libraries/LibJS/Tests/object-basic.js b/Libraries/LibJS/Tests/object-basic.js
index 1334ee6e1b..2320304fc0 100644
--- a/Libraries/LibJS/Tests/object-basic.js
+++ b/Libraries/LibJS/Tests/object-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var o = { 1: 23, foo: "bar", "hello": "friends" };
     assert(o[1] === 23);
diff --git a/Libraries/LibJS/Tests/parser-unary-associativity.js b/Libraries/LibJS/Tests/parser-unary-associativity.js
index 1bc9b05f8e..6ed427110a 100644
--- a/Libraries/LibJS/Tests/parser-unary-associativity.js
+++ b/Libraries/LibJS/Tests/parser-unary-associativity.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var o = {};
     o.a = 1;
diff --git a/Libraries/LibJS/Tests/run-tests b/Libraries/LibJS/Tests/run-tests
index 346039fef1..7cc52252cc 100755
--- a/Libraries/LibJS/Tests/run-tests
+++ b/Libraries/LibJS/Tests/run-tests
@@ -13,6 +13,7 @@ pass_count=0
 fail_count=0
 count=0
 
+GLOBIGNORE=test-common.js
 for f in *.js; do
     result=`$js_program -t $f`
     if [ "$result" = "PASS" ]; then
diff --git a/Libraries/LibJS/Tests/switch-break.js b/Libraries/LibJS/Tests/switch-break.js
index 2b57f02723..0fe5fe1aab 100644
--- a/Libraries/LibJS/Tests/switch-break.js
+++ b/Libraries/LibJS/Tests/switch-break.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var i = 0;
     var three;
diff --git a/Libraries/LibJS/Tests/ternary-basic.js b/Libraries/LibJS/Tests/ternary-basic.js
index 72aad18369..6eb62bda3d 100644
--- a/Libraries/LibJS/Tests/ternary-basic.js
+++ b/Libraries/LibJS/Tests/ternary-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var x = 1;
 
diff --git a/Libraries/LibJS/Tests/test-common.js b/Libraries/LibJS/Tests/test-common.js
new file mode 100644
index 0000000000..b466a3f010
--- /dev/null
+++ b/Libraries/LibJS/Tests/test-common.js
@@ -0,0 +1,16 @@
+
+function AssertionError(message) {
+    var instance = new Error(message);
+    instance.name = 'AssertionError';
+    Object.setPrototypeOf(instance, Object.getPrototypeOf(this));
+    return instance;
+}
+
+function assert(value) {
+    if (!value)
+        throw new AssertionError("The assertion failed!");
+}
+
+function assertNotReached() {
+    throw new AssertionError("assertNotReached() was reached!");
+}
diff --git a/Libraries/LibJS/Tests/throw-basic.js b/Libraries/LibJS/Tests/throw-basic.js
index 3b5106ec43..2c8190480e 100644
--- a/Libraries/LibJS/Tests/throw-basic.js
+++ b/Libraries/LibJS/Tests/throw-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     throw 1;
     assertNotReached();
diff --git a/Libraries/LibJS/Tests/to-number-basic.js b/Libraries/LibJS/Tests/to-number-basic.js
index cf41bb8b3c..e0d07a51fe 100644
--- a/Libraries/LibJS/Tests/to-number-basic.js
+++ b/Libraries/LibJS/Tests/to-number-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(+false === 0);
     assert(-false === 0);
diff --git a/Libraries/LibJS/Tests/typeof-basic.js b/Libraries/LibJS/Tests/typeof-basic.js
index ee0d67eaa3..a1ba3dd5f7 100644
--- a/Libraries/LibJS/Tests/typeof-basic.js
+++ b/Libraries/LibJS/Tests/typeof-basic.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     assert(typeof "foo" === "string");
     assert(!(typeof "foo" !== "string"));
diff --git a/Libraries/LibJS/Tests/var-multiple-declarator.js b/Libraries/LibJS/Tests/var-multiple-declarator.js
index 49c76e276b..e4cac238c5 100644
--- a/Libraries/LibJS/Tests/var-multiple-declarator.js
+++ b/Libraries/LibJS/Tests/var-multiple-declarator.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     var a = 1, b = 2, c = a + b;
     assert(a === 1);
diff --git a/Libraries/LibJS/Tests/var-scoping.js b/Libraries/LibJS/Tests/var-scoping.js
index 65ef361c97..4e88a9de0b 100644
--- a/Libraries/LibJS/Tests/var-scoping.js
+++ b/Libraries/LibJS/Tests/var-scoping.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
     function foo() {
         i = 3;
diff --git a/Libraries/LibJS/Tests/variable-declaration.js b/Libraries/LibJS/Tests/variable-declaration.js
index 461a46ecd2..b1231925db 100644
--- a/Libraries/LibJS/Tests/variable-declaration.js
+++ b/Libraries/LibJS/Tests/variable-declaration.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 try {
 
     const constantValue = 1;
diff --git a/Libraries/LibJS/Tests/variable-undefined.js b/Libraries/LibJS/Tests/variable-undefined.js
index 1ad67efb41..604ace3ced 100644
--- a/Libraries/LibJS/Tests/variable-undefined.js
+++ b/Libraries/LibJS/Tests/variable-undefined.js
@@ -1,3 +1,5 @@
+load("test-common.js");
+
 function foo(a) {
     return a;
 }
diff --git a/Userland/js.cpp b/Userland/js.cpp
index a31b932792..bb09165b17 100644
--- a/Userland/js.cpp
+++ b/Userland/js.cpp
@@ -372,28 +372,9 @@ void repl(JS::Interpreter& interpreter)
     }
 }
 
-JS::Value assert_impl(JS::Interpreter& interpreter)
-{
-    if (!interpreter.argument_count())
-        return interpreter.throw_exception<JS::TypeError>("No arguments specified");
-
-    auto assertion_value = interpreter.argument(0).to_boolean();
-    if (!assertion_value)
-        return interpreter.throw_exception<JS::Error>("AssertionError", "The assertion failed!");
-
-    return JS::Value(assertion_value);
-}
-
-JS::Value assert_not_reached(JS::Interpreter& interpreter)
-{
-    return interpreter.throw_exception<JS::Error>("AssertionError", "assertNotReached() was reached!");
-}
-
 void enable_test_mode(JS::Interpreter& interpreter)
 {
     interpreter.global_object().put_native_function("load", ReplObject::load_file);
-    interpreter.global_object().put_native_function("assert", assert_impl);
-    interpreter.global_object().put_native_function("assertNotReached", assert_not_reached);
 }
 
 int main(int argc, char** argv)