From 21e627b35daa98ba7f725a3565cf54f31ab57b5e Mon Sep 17 00:00:00 2001
From: rwaldron <waldron.rick@gmail.com>
Date: Wed, 11 Aug 2021 10:42:40 -0400
Subject: [PATCH] Transform legacy format to harness assertions

---
 .../Array/prototype/join/S15.4.4.5_A2_T4.js   |  98 +++++---------
 .../Array/prototype/join/S15.4.4.5_A3.1_T2.js | 107 ++++++++-------
 .../Array/prototype/join/S15.4.4.5_A3.2_T2.js |  42 ++----
 .../Array/prototype/join/S15.4.4.5_A6.7.js    |  11 +-
 .../Array/prototype/pop/S15.4.4.6_A2_T4.js    |  74 ++++-------
 .../Array/prototype/pop/S15.4.4.6_A5.7.js     |  11 +-
 .../Array/prototype/push/S15.4.4.7_A2_T3.js   |  75 ++++-------
 .../Array/prototype/push/S15.4.4.7_A3.js      |  21 ++-
 .../Array/prototype/push/S15.4.4.7_A6.7.js    |  11 +-
 .../Array/prototype/reverse/S15.4.4.8_A5.7.js |  11 +-
 .../Array/prototype/shift/S15.4.4.9_A2_T5.js  |  74 ++++-------
 .../Array/prototype/shift/S15.4.4.9_A5.7.js   |  11 +-
 .../Array/prototype/slice/S15.4.4.10_A3_T1.js |  24 ++--
 .../Array/prototype/slice/S15.4.4.10_A3_T2.js |  23 ++--
 .../Array/prototype/slice/S15.4.4.10_A5.7.js  |  11 +-
 .../Array/prototype/sort/S15.4.4.11_A5_T1.js  |  17 +--
 .../Array/prototype/sort/S15.4.4.11_A7.7.js   |  11 +-
 .../Array/prototype/splice/S15.4.4.12_A5.7.js |  11 +-
 .../toLocaleString/S15.4.4.3_A4.7.js          |  11 +-
 .../prototype/toString/S15.4.4.2_A1_T4.js     | 125 +++++-------------
 .../prototype/toString/S15.4.4.2_A4.7.js      |  11 +-
 .../prototype/unshift/S15.4.4.13_A2_T3.js     |  74 ++++-------
 .../prototype/unshift/S15.4.4.13_A5.7.js      |  11 +-
 23 files changed, 320 insertions(+), 555 deletions(-)

diff --git a/test/built-ins/Array/prototype/join/S15.4.4.5_A2_T4.js b/test/built-ins/Array/prototype/join/S15.4.4.5_A2_T4.js
index 3c1fa2d431..b84d697950 100644
--- a/test/built-ins/Array/prototype/join/S15.4.4.5_A2_T4.js
+++ b/test/built-ins/Array/prototype/join/S15.4.4.5_A2_T4.js
@@ -15,112 +15,80 @@ var obj = {};
 obj.join = Array.prototype.join;
 
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 3
   }
 };
-if (obj.join() !== ",,") {
-  throw new Test262Error('#1: obj.length = {valueOf: function() {return 3}}  obj.join() === ",,". Actual: ' + (obj.join()));
-}
+assert.sameValue(obj.join(), ",,", 'obj.join() must return ",,"');
 
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 3
   },
-  toString: function() {
+  toString() {
     return 2
   }
 };
-if (obj.join() !== ",,") {
-  throw new Test262Error('#2: obj.length = {valueOf: function() {return 3}, toString: function() {return 2}}  obj.join() === ",,". Actual: ' + (obj.join()));
-}
+assert.sameValue(obj.join(), ",,", 'obj.join() must return ",,"');
 
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 3
   },
-  toString: function() {
+  toString() {
     return {}
   }
 };
-if (obj.join() !== ",,") {
-  throw new Test262Error('#3: obj.length = {valueOf: function() {return 3}, toString: function() {return {}}}  obj.join() === ",,". Actual: ' + (obj.join()));
-}
-
-try {
-  obj.length = {
-    valueOf: function() {
-      return 3
-    },
-    toString: function() {
-      throw "error"
-    }
-  };
-  if (obj.join() !== ",,") {
-    throw new Test262Error('#4.1: obj.length = {valueOf: function() {return 3}, toString: function() {throw "error"}}; obj.join() === ",". Actual: ' + (obj.join()));
-  }
-}
-catch (e) {
-  if (e === "error") {
-    throw new Test262Error('#4.2: obj.length = {valueOf: function() {return 3}, toString: function() {throw "error"}}; obj.join() not throw "error"');
-  } else {
-    throw new Test262Error('#4.3: obj.length = {valueOf: function() {return 3}, toString: function() {throw "error"}}; obj.join() not throw Error. Actual: ' + (e));
-  }
-}
+assert.sameValue(obj.join(), ",,", 'obj.join() must return ",,"');
 
 obj.length = {
-  toString: function() {
+  valueOf() {
+    return 3
+  },
+  toString() {
+    throw new Test262Error();
+  }
+};
+assert.sameValue(obj.join(), ",,", 'obj.join() must return ",,"');
+
+obj.length = {
+  toString() {
     return 2
   }
 };
-if (obj.join() !== ",") {
-  throw new Test262Error('#5: obj.length = {toString: function() {return 2}}  obj.join() === ",". Actual: ' + (obj.join()));
-}
+assert.sameValue(obj.join(), ",", 'obj.join() must return ","');
 
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return {}
   },
-  toString: function() {
+  toString() {
     return 2
   }
 }
-if (obj.join() !== ",") {
-  throw new Test262Error('#6: obj.length = {valueOf: function() {return {}}, toString: function() {return 2}}  obj.join() === ",". Actual: ' + (obj.join()));
-}
+assert.sameValue(obj.join(), ",", 'obj.join() must return ","');
 
-try {
+assert.throws(Test262Error, () => {
   obj.length = {
-    valueOf: function() {
-      throw "error"
+    valueOf() {
+      throw new Test262Error();
     },
-    toString: function() {
+    toString() {
       return 2
     }
   };
   obj.join();
-  throw new Test262Error('#7.1: obj.length = {valueOf: function() {throw "error"}, toString: function() {return 2}}; obj.join() throw "error". Actual: ' + (obj.join()));
-}
-catch (e) {
-  if (e !== "error") {
-    throw new Test262Error('#7.2: obj.length = {valueOf: function() {throw "error"}, toString: function() {return 2}}; obj.join() throw "error". Actual: ' + (e));
-  }
-}
+});
 
-try {
+assert.throws(TypeError, () => {
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       return {}
     },
-    toString: function() {
+    toString() {
       return {}
     }
   };
   obj.join();
-  throw new Test262Error('#8.1: obj.length = {valueOf: function() {return {}}, toString: function() {return {}}}  obj.join() throw TypeError. Actual: ' + (obj.join()));
-}
-catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#8,2: obj.length = {valueOf: function() {return {}}, toString: function() {return {}}}  obj.join() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/join/S15.4.4.5_A3.1_T2.js b/test/built-ins/Array/prototype/join/S15.4.4.5_A3.1_T2.js
index c7ee77ad80..213011db07 100644
--- a/test/built-ins/Array/prototype/join/S15.4.4.5_A3.1_T2.js
+++ b/test/built-ins/Array/prototype/join/S15.4.4.5_A3.1_T2.js
@@ -11,127 +11,134 @@ description: >
 
 var x = new Array(0, 1, 2, 3);
 var object = {
-  valueOf: function() {
+  valueOf() {
     return "+"
   }
 };
-if (x.join(object) !== "0[object Object]1[object Object]2[object Object]3") {
-  throw new Test262Error('#1: var object = {valueOf: function() {return "+"}}; x.join(object) === "0[object Object]1[object Object]2[object Object]3". Actual: ' + (x.join(object)));
-}
+
+assert.sameValue(
+  x.join(object),
+  "0[object Object]1[object Object]2[object Object]3",
+  'x.join({valueOf() {return "+"}}) must return "0[object Object]1[object Object]2[object Object]3"'
+);
 
 var object = {
-  valueOf: function() {
+  valueOf() {
     return "+"
   },
-  toString: function() {
+  toString() {
     return "*"
   }
 };
-if (x.join(object) !== "0*1*2*3") {
-  throw new Test262Error('#2: var object = {valueOf: function() {return "+"}, toString: function() {return "*"}}; x.join(object) === "0*1*2*3". Actual: ' + (x.join(object)));
-}
+
+assert.sameValue(
+  x.join(object),
+  "0*1*2*3",
+  'x.join("{valueOf() {return "+"}, toString() {return "*"}}) must return "0*1*2*3"'
+);
 
 var object = {
-  valueOf: function() {
+  valueOf() {
     return "+"
   },
-  toString: function() {
+  toString() {
     return {}
   }
 };
-if (x.join(object) !== "0+1+2+3") {
-  throw new Test262Error('#3: var object = {valueOf: function() {return "+"}, toString: function() {return {}}}; x.join(object) === "0+1+2+3". Actual: ' + (x.join(object)));
-}
+
+assert.sameValue(
+  x.join(object),
+  "0+1+2+3",
+  'x.join({valueOf() {return "+"}, toString() {return {}}}) must return "0+1+2+3"'
+);
 
 try {
   var object = {
-    valueOf: function() {
+    valueOf() {
       throw "error"
     },
-    toString: function() {
+    toString() {
       return "*"
     }
   };
-  if (x.join(object) !== "0*1*2*3") {
-    throw new Test262Error('#4.1: var object = {valueOf: function() {throw "error"}, toString: function() {return "*"}}; x.join(object) === "0*1*2*3". Actual: ' + (x.join(object)));
-  }
+
+  assert.sameValue(
+    x.join(object),
+    "0*1*2*3",
+    'x.join("{valueOf() {throw "error"}, toString() {return "*"}}) must return "0*1*2*3"'
+  );
 }
 catch (e) {
-  if (e === "error") {
-    throw new Test262Error('#4.2: var object = {valueOf: function() {throw "error"}, toString: function() {return "*"}}; x.join(object) not throw "error"');
-  } else {
-    throw new Test262Error('#4.3: var object = {valueOf: function() {throw "error"}, toString: function() {return "*"}}; x.join(object) not throw Error. Actual: ' + (e));
-  }
+  assert.notSameValue(e, "error", 'The value of e is not "error"');
 }
 
 var object = {
-  toString: function() {
+  toString() {
     return "*"
   }
 };
-if (x.join(object) !== "0*1*2*3") {
-  throw new Test262Error('#5: var object = {toString: function() {return "*"}}; x.join(object) === "0*1*2*3". Actual: ' + (x.join(object)));
-}
+assert.sameValue(x.join(object), "0*1*2*3", 'x.join({toString() {return "*"}}) must return "0*1*2*3"');
 
 var object = {
-  valueOf: function() {
+  valueOf() {
     return {}
   },
-  toString: function() {
+  toString() {
     return "*"
   }
 }
-if (x.join(object) !== "0*1*2*3") {
-  throw new Test262Error('#6: var object = {valueOf: function() {return {}}, toString: function() {return "*"}}; x.join(object) === "0*1*2*3". Actual: ' + (x.join(object)));
-}
+
+assert.sameValue(
+  x.join(object),
+  "0*1*2*3",
+  'x.join({valueOf() {return {}}, toString() {return "*"}}) must return "0*1*2*3"'
+);
 
 try {
   var object = {
-    valueOf: function() {
+    valueOf() {
       return "+"
     },
-    toString: function() {
+    toString() {
       throw "error"
     }
   };
   x.join(object);
-  throw new Test262Error('#7.1: var object = {valueOf: function() {return "+"}, toString: function() {throw "error"}}; x.join(object) throw "error". Actual: ' + (x.join(object)));
+  throw new Test262Error('#7.1: var object = {valueOf() {return "+"}, toString() {throw "error"}}; x.join(object) throw "error". Actual: ' + (x.join(object)));
 }
 catch (e) {
-  if (e !== "error") {
-    throw new Test262Error('#7.2: var object = {valueOf: function() {return "+"}, toString: function() {throw "error"}}; x.join(object) throw "error". Actual: ' + (e));
-  }
+  assert.sameValue(e, "error", 'The value of e is expected to be "error"');
 }
 
 try {
   var object = {
-    valueOf: function() {
+    valueOf() {
       return {}
     },
-    toString: function() {
+    toString() {
       return {}
     }
   };
   x.join(object);
-  throw new Test262Error('#8.1: var object = {valueOf: function() {return {}}, toString: function() {return {}}}; x.join(object) throw TypeError. Actual: ' + (x.join(object)));
+  throw new Test262Error('#8.1: var object = {valueOf() {return {}}, toString() {return {}}}; x.join(object) throw TypeError. Actual: ' + (x.join(object)));
 }
 catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#8.2: var object = {valueOf: function() {return {}}, toString: function() {return {}}}; x.join(object) throw TypeError. Actual: ' + (e));
-  }
+  assert.sameValue(
+    e instanceof TypeError,
+    true,
+    'The result of evaluating (e instanceof TypeError) is expected to be true'
+  );
 }
 
 try {
   var object = {
-    toString: function() {
+    toString() {
       throw "error"
     }
   };
   [].join(object);
-  throw new Test262Error('#9.1: var object = {toString: function() {throw "error"}}; [].join(object) throw "error". Actual: ' + ([].join(object)));
+  throw new Test262Error('#9.1: var object = {toString() {throw "error"}}; [].join(object) throw "error". Actual: ' + ([].join(object)));
 }
 catch (e) {
-  if (e !== "error") {
-    throw new Test262Error('#9.2: var object = {toString: function() {throw "error"}}; [].join(object) throw "error". Actual: ' + (e));
-  }
+  assert.sameValue(e, "error", 'The value of e is expected to be "error"');
 }
diff --git a/test/built-ins/Array/prototype/join/S15.4.4.5_A3.2_T2.js b/test/built-ins/Array/prototype/join/S15.4.4.5_A3.2_T2.js
index 2ea887456b..b6575d611d 100644
--- a/test/built-ins/Array/prototype/join/S15.4.4.5_A3.2_T2.js
+++ b/test/built-ins/Array/prototype/join/S15.4.4.5_A3.2_T2.js
@@ -13,9 +13,7 @@ var object = {
   }
 };
 var x = new Array(object);
-if (x.join() !== "[object Object]") {
-  throw new Test262Error('#1: var object = {valueOf: function() {return "+"}} var x = new Array(object); x.join() === "[object Object]". Actual: ' + (x.join()));
-}
+assert.sameValue(x.join(), "[object Object]", 'x.join() must return "[object Object]"');
 
 var object = {
   valueOf: function() {
@@ -26,9 +24,7 @@ var object = {
   }
 };
 var x = new Array(object);
-if (x.join() !== "*") {
-  throw new Test262Error('#2: var object = {valueOf: function() {return "+"}, toString: function() {return "*"}} var x = new Array(object); x.join() === "*". Actual: ' + (x.join()));
-}
+assert.sameValue(x.join(), "*", 'x.join() must return "*"');
 
 var object = {
   valueOf: function() {
@@ -39,9 +35,7 @@ var object = {
   }
 };
 var x = new Array(object);
-if (x.join() !== "+") {
-  throw new Test262Error('#3: var object = {valueOf: function() {return "+"}, toString: function() {return {}}} var x = new Array(object); x.join() === "+". Actual: ' + (x.join()));
-}
+assert.sameValue(x.join(), "+", 'x.join() must return "+"');
 
 try {
   var object = {
@@ -53,16 +47,10 @@ try {
     }
   };
   var x = new Array(object);
-  if (x.join() !== "*") {
-    throw new Test262Error('#4.1: var object = {valueOf: function() {throw "error"}, toString: function() {return "*"}} var x = new Array(object); x.join() === "*". Actual: ' + (x.join()));
-  }
+  assert.sameValue(x.join(), "*", 'x.join() must return "*"');
 }
 catch (e) {
-  if (e === "error") {
-    throw new Test262Error('#4.2: var object = {valueOf: function() {throw "error"}, toString: function() {return "*"}} var x = new Array(object); x.join() not throw "error"');
-  } else {
-    throw new Test262Error('#4.3: var object = {valueOf: function() {throw "error"}, toString: function() {return "*"}} var x = new Array(object); x.join() not throw Error. Actual: ' + (e));
-  }
+  assert.notSameValue(e, "error", 'The value of e is not "error"');
 }
 
 var object = {
@@ -71,9 +59,7 @@ var object = {
   }
 };
 var x = new Array(object);
-if (x.join() !== "*") {
-  throw new Test262Error('#5: var object = {toString: function() {return "*"}} var x = new Array(object); x.join() === "*". Actual: ' + (x.join()));
-}
+assert.sameValue(x.join(), "*", 'x.join() must return "*"');
 
 var object = {
   valueOf: function() {
@@ -84,9 +70,7 @@ var object = {
   }
 }
 var x = new Array(object);
-if (x.join() !== "*") {
-  throw new Test262Error('#6: var object = {valueOf: function() {return {}}, toString: function() {return "*"}} var x = new Array(object); x.join() === "*". Actual: ' + (x.join()));
-}
+assert.sameValue(x.join(), "*", 'x.join() must return "*"');
 
 try {
   var object = {
@@ -102,9 +86,7 @@ try {
   throw new Test262Error('#7.1: var object = {valueOf: function() {return "+"}, toString: function() {throw "error"}} var x = new Array(object); x.join() throw "error". Actual: ' + (x.join()));
 }
 catch (e) {
-  if (e !== "error") {
-    throw new Test262Error('#7.2: var object = {valueOf: function() {return "+"}, toString: function() {throw "error"}} var x = new Array(object); x.join() throw "error". Actual: ' + (e));
-  }
+  assert.sameValue(e, "error", 'The value of e is expected to be "error"');
 }
 
 try {
@@ -121,7 +103,9 @@ try {
   throw new Test262Error('#8.1: var object = {valueOf: function() {return {}}, toString: function() {return {}}} var x = new Array(object); x.join() throw TypeError. Actual: ' + (x.join()));
 }
 catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#8.2: var object = {valueOf: function() {return {}}, toString: function() {return {}}} var x = new Array(object); x.join() throw TypeError. Actual: ' + (e));
-  }
+  assert.sameValue(
+    e instanceof TypeError,
+    true,
+    'The result of evaluating (e instanceof TypeError) is expected to be true'
+  );
 }
diff --git a/test/built-ins/Array/prototype/join/S15.4.4.5_A6.7.js b/test/built-ins/Array/prototype/join/S15.4.4.5_A6.7.js
index 8559cbec7b..8ff58d4dfb 100644
--- a/test/built-ins/Array/prototype/join/S15.4.4.5_A6.7.js
+++ b/test/built-ins/Array/prototype/join/S15.4.4.5_A6.7.js
@@ -9,12 +9,7 @@ description: >
     throw a TypeError exception
 ---*/
 
-
-try {
+assert.throws(TypeError, () => {
   new Array.prototype.join();
-  throw new Test262Error('#1.1: new Array.prototype.join() throw TypeError. Actual: ' + (new Array.prototype.join()));
-} catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#1.2: new Array.prototype.join() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/pop/S15.4.4.6_A2_T4.js b/test/built-ins/Array/prototype/pop/S15.4.4.6_A2_T4.js
index 82b7c4dbd7..e372029475 100644
--- a/test/built-ins/Array/prototype/pop/S15.4.4.6_A2_T4.js
+++ b/test/built-ins/Array/prototype/pop/S15.4.4.6_A2_T4.js
@@ -16,125 +16,109 @@ obj.pop = Array.prototype.pop;
 
 obj[0] = -1;
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 1
   }
 };
 var pop = obj.pop();
-if (pop !== -1) {
-  throw new Test262Error('#1: obj[0] = -1; obj.length = {valueOf: function() {return 1}}  obj.pop() === -1. Actual: ' + (pop));
-}
+assert.sameValue(pop, -1, 'The value of pop is expected to be -1');
 
 obj[0] = -1;
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 1
   },
-  toString: function() {
+  toString() {
     return 0
   }
 };
 var pop = obj.pop();
-if (pop !== -1) {
-  throw new Test262Error('#0: obj[0] = -1; obj.length = {valueOf: function() {return 1}, toString: function() {return 0}}  obj.pop() === -1. Actual: ' + (pop));
-}
+assert.sameValue(pop, -1, 'The value of pop is expected to be -1');
 
 obj[0] = -1;
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 1
   },
-  toString: function() {
+  toString() {
     return {}
   }
 };
 var pop = obj.pop();
-if (pop !== -1) {
-  throw new Test262Error('#3: obj[0] = -1; obj.length = {valueOf: function() {return 1}, toString: function() {return {}}}  obj.pop() === -1. Actual: ' + (pop));
-}
+assert.sameValue(pop, -1, 'The value of pop is expected to be -1');
 
 try {
   obj[0] = -1;
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       return 1
     },
-    toString: function() {
+    toString() {
       throw "error"
     }
   };
   var pop = obj.pop();
-  if (pop !== -1) {
-    throw new Test262Error('#4.1: obj[0] = -1; obj.length = {valueOf: function() {return 1}, toString: function() {throw "error"}}; obj.pop() === ",". Actual: ' + (pop));
-  }
+  assert.sameValue(pop, -1, 'The value of pop is expected to be -1');
 }
 catch (e) {
-  if (e === "error") {
-    throw new Test262Error('#4.2: obj[0] = -1; obj.length = {valueOf: function() {return 1}, toString: function() {throw "error"}}; obj.pop() not throw "error"');
-  } else {
-    throw new Test262Error('#4.3: obj[0] = -1; obj.length = {valueOf: function() {return 1}, toString: function() {throw "error"}}; obj.pop() not throw Error. Actual: ' + (e));
-  }
+  assert.notSameValue(e, "error", 'The value of e is not "error"');
 }
 
 obj[0] = -1;
 obj.length = {
-  toString: function() {
+  toString() {
     return 0
   }
 };
 var pop = obj.pop();
-if (pop !== undefined) {
-  throw new Test262Error('#5: obj[0] = -1; obj.length = {toString: function() {return 0}}  obj.pop() === undefined. Actual: ' + (pop));
-}
+assert.sameValue(pop, undefined, 'The value of pop is expected to equal undefined');
 
 obj[0] = -1;
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return {}
   },
-  toString: function() {
+  toString() {
     return 0
   }
 }
 var pop = obj.pop();
-if (pop !== undefined) {
-  throw new Test262Error('#6: obj[0] = -1; obj.length = {valueOf: function() {return {}}, toString: function() {return 0}}  obj.pop() === undefined. Actual: ' + (pop));
-}
+assert.sameValue(pop, undefined, 'The value of pop is expected to equal undefined');
 
 try {
   obj[0] = -1;
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       throw "error"
     },
-    toString: function() {
+    toString() {
       return 0
     }
   };
   var pop = obj.pop();
-  throw new Test262Error('#7.1: obj[0] = -1; obj.length = {valueOf: function() {throw "error"}, toString: function() {return 0}}; obj.pop() throw "error". Actual: ' + (pop));
+  throw new Test262Error('#7.1: obj[0] = -1; obj.length = {valueOf() {throw "error"}, toString() {return 0}}; obj.pop() throw "error". Actual: ' + (pop));
 }
 catch (e) {
-  if (e !== "error") {
-    throw new Test262Error('#7.2: obj[0] = -1; obj.length = {valueOf: function() {throw "error"}, toString: function() {return 0}}; obj.pop() throw "error". Actual: ' + (e));
-  }
+  assert.sameValue(e, "error", 'The value of e is expected to be "error"');
 }
 
 try {
   obj[0] = -1;
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       return {}
     },
-    toString: function() {
+    toString() {
       return {}
     }
   };
   var pop = obj.pop();
-  throw new Test262Error('#8.1: obj[0] = -1; obj.length = {valueOf: function() {return {}}, toString: function() {return {}}}  obj.pop() throw TypeError. Actual: ' + (pop));
+  throw new Test262Error('#8.1: obj[0] = -1; obj.length = {valueOf() {return {}}, toString() {return {}}}  obj.pop() throw TypeError. Actual: ' + (pop));
 }
 catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#8.2: obj[0] = -1; obj.length = {valueOf: function() {return {}}, toString: function() {return {}}}  obj.pop() throw TypeError. Actual: ' + (e));
-  }
+  assert.sameValue(
+    e instanceof TypeError,
+    true,
+    'The result of evaluating (e instanceof TypeError) is expected to be true'
+  );
 }
diff --git a/test/built-ins/Array/prototype/pop/S15.4.4.6_A5.7.js b/test/built-ins/Array/prototype/pop/S15.4.4.6_A5.7.js
index cd7b3967bc..e1cb815a31 100644
--- a/test/built-ins/Array/prototype/pop/S15.4.4.6_A5.7.js
+++ b/test/built-ins/Array/prototype/pop/S15.4.4.6_A5.7.js
@@ -9,12 +9,7 @@ description: >
     throw a TypeError exception
 ---*/
 
-
-try {
+assert.throws(TypeError, () => {
   new Array.prototype.pop();
-  throw new Test262Error('#1.1: new Array.prototype.pop() throw TypeError. Actual: ' + (new Array.prototype.pop()));
-} catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#1.2: new Array.prototype.pop() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/push/S15.4.4.7_A2_T3.js b/test/built-ins/Array/prototype/push/S15.4.4.7_A2_T3.js
index 8e87c8bf67..b4183bb05d 100644
--- a/test/built-ins/Array/prototype/push/S15.4.4.7_A2_T3.js
+++ b/test/built-ins/Array/prototype/push/S15.4.4.7_A2_T3.js
@@ -15,121 +15,104 @@ var obj = {};
 obj.push = Array.prototype.push;
 
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 3
   }
 };
 var push = obj.push();
-if (push !== 3) {
-  throw new Test262Error('#1:  obj.length = {valueOf: function() {return 3}}  obj.push() === 3. Actual: ' + (push));
-}
+assert.sameValue(push, 3, 'The value of push is expected to be 3');
 
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 3
   },
-  toString: function() {
+  toString() {
     return 1
   }
 };
 var push = obj.push();
-if (push !== 3) {
-  throw new Test262Error('#0:  obj.length = {valueOf: function() {return 3}, toString: function() {return 1}}  obj.push() === 3. Actual: ' + (push));
-}
+assert.sameValue(push, 3, 'The value of push is expected to be 3');
 
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 3
   },
-  toString: function() {
+  toString() {
     return {}
   }
 };
 var push = obj.push();
-if (push !== 3) {
-  throw new Test262Error('#1:  obj.length = {valueOf: function() {return 3}, toString: function() {return {}}}  obj.push() === 3. Actual: ' + (push));
-}
+assert.sameValue(push, 3, 'The value of push is expected to be 3');
 
 try {
-
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       return 3
     },
-    toString: function() {
+    toString() {
       throw "error"
     }
   };
   var push = obj.push();
-  if (push !== 3) {
-    throw new Test262Error('#4.1:  obj.length = {valueOf: function() {return 3}, toString: function() {throw "error"}}; obj.push() === ",". Actual: ' + (push));
-  }
+  assert.sameValue(push, 3, 'The value of push is expected to be 3');
 }
 catch (e) {
-  if (e === "error") {
-    throw new Test262Error('#4.2:  obj.length = {valueOf: function() {return 3}, toString: function() {throw "error"}}; obj.push() not throw "error"');
-  } else {
-    throw new Test262Error('#4.3:  obj.length = {valueOf: function() {return 3}, toString: function() {throw "error"}}; obj.push() not throw Error. Actual: ' + (e));
-  }
+  assert.notSameValue(e, "error", 'The value of e is not "error"');
 }
 
 obj.length = {
-  toString: function() {
+  toString() {
     return 1
   }
 };
 var push = obj.push();
-if (push !== 1) {
-  throw new Test262Error('#5:  obj.length = {toString: function() {return 1}}  obj.push() === 1. Actual: ' + (push));
-}
+assert.sameValue(push, 1, 'The value of push is expected to be 1');
 
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return {}
   },
-  toString: function() {
+  toString() {
     return 1
   }
 }
 var push = obj.push();
-if (push !== 1) {
-  throw new Test262Error('#6:  obj.length = {valueOf: function() {return {}}, toString: function() {return 1}}  obj.push() === 1. Actual: ' + (push));
-}
+assert.sameValue(push, 1, 'The value of push is expected to be 1');
 
 try {
 
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       throw "error"
     },
-    toString: function() {
+    toString() {
       return 1
     }
   };
   var push = obj.push();
-  throw new Test262Error('#7.1:  obj.length = {valueOf: function() {throw "error"}, toString: function() {return 1}}; obj.push() throw "error". Actual: ' + (push));
+  throw new Test262Error('#7.1:  obj.length = {valueOf() {throw "error"}, toString() {return 1}}; obj.push() throw "error". Actual: ' + (push));
 }
 catch (e) {
-  if (e !== "error") {
-    throw new Test262Error('#7.2:  obj.length = {valueOf: function() {throw "error"}, toString: function() {return 1}}; obj.push() throw "error". Actual: ' + (e));
-  }
+  assert.sameValue(e, "error", 'The value of e is expected to be "error"');
 }
 
 try {
 
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       return {}
     },
-    toString: function() {
+    toString() {
       return {}
     }
   };
   var push = obj.push();
-  throw new Test262Error('#8.1:  obj.length = {valueOf: function() {return {}}, toString: function() {return {}}}  obj.push() throw TypeError. Actual: ' + (push));
+  throw new Test262Error('#8.1:  obj.length = {valueOf() {return {}}, toString() {return {}}}  obj.push() throw TypeError. Actual: ' + (push));
 }
 catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#8.2:  obj.length = {valueOf: function() {return {}}, toString: function() {return {}}}  obj.push() throw TypeError. Actual: ' + (e));
-  }
+  assert.sameValue(
+    e instanceof TypeError,
+    true,
+    'The result of evaluating (e instanceof TypeError) is expected to be true'
+  );
 }
diff --git a/test/built-ins/Array/prototype/push/S15.4.4.7_A3.js b/test/built-ins/Array/prototype/push/S15.4.4.7_A3.js
index 1d8f4f29a6..1bcd57ef0c 100644
--- a/test/built-ins/Array/prototype/push/S15.4.4.7_A3.js
+++ b/test/built-ins/Array/prototype/push/S15.4.4.7_A3.js
@@ -11,23 +11,18 @@ var x = [];
 x.length = 4294967295;
 
 var push = x.push();
-if (push !== 4294967295) {
-  throw new Test262Error('#1: x = []; x.length = 4294967295; x.push() === 4294967295. Actual: ' + (push));
-}
+assert.sameValue(push, 4294967295, 'The value of push is expected to be 4294967295');
 
 try {
   x.push("x");
   throw new Test262Error('#2.1: x = []; x.length = 4294967295; x.push("x") throw RangeError. Actual: ' + (push));
 } catch (e) {
-  if ((e instanceof RangeError) !== true) {
-    throw new Test262Error('#2.2: x = []; x.length = 4294967295; x.push("x") throw RangeError. Actual: ' + (e));
-  }
+  assert.sameValue(
+    e instanceof RangeError,
+    true,
+    'The result of evaluating (e instanceof RangeError) is expected to be true'
+  );
 }
 
-if (x[4294967295] !== "x") {
-  throw new Test262Error('#3: x = []; x.length = 4294967295; try {x.push("x")}catch(e){}; x[4294967295] === "x". Actual: ' + (x[4294967295]));
-}
-
-if (x.length !== 4294967295) {
-  throw new Test262Error('#4: x = []; x.length = 4294967295; try {x.push("x")}catch(e){}; x.length === 4294967295. Actual: ' + (x.length));
-}
+assert.sameValue(x[4294967295], "x", 'The value of x[4294967295] is expected to be "x"');
+assert.sameValue(x.length, 4294967295, 'The value of x.length is expected to be 4294967295');
diff --git a/test/built-ins/Array/prototype/push/S15.4.4.7_A6.7.js b/test/built-ins/Array/prototype/push/S15.4.4.7_A6.7.js
index 4bb5f526fd..3eacb84df3 100644
--- a/test/built-ins/Array/prototype/push/S15.4.4.7_A6.7.js
+++ b/test/built-ins/Array/prototype/push/S15.4.4.7_A6.7.js
@@ -9,12 +9,7 @@ description: >
     throw a TypeError exception
 ---*/
 
-
-try {
+assert.throws(TypeError, () => {
   new Array.prototype.push();
-  throw new Test262Error('#1.1: new Array.prototype.push() throw TypeError. Actual: ' + (new Array.prototype.push()));
-} catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#1.2: new Array.prototype.push() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/reverse/S15.4.4.8_A5.7.js b/test/built-ins/Array/prototype/reverse/S15.4.4.8_A5.7.js
index d1ac302439..e17bc4d5c8 100644
--- a/test/built-ins/Array/prototype/reverse/S15.4.4.8_A5.7.js
+++ b/test/built-ins/Array/prototype/reverse/S15.4.4.8_A5.7.js
@@ -9,12 +9,7 @@ description: >
     throw a TypeError exception
 ---*/
 
-
-try {
+assert.throws(TypeError, () => {
   new Array.prototype.reverse();
-  throw new Test262Error('#1.1: new Array.prototype.reverse() throw TypeError. Actual: ' + (new Array.prototype.reverse()));
-} catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#1.2: new Array.prototype.reverse() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/shift/S15.4.4.9_A2_T5.js b/test/built-ins/Array/prototype/shift/S15.4.4.9_A2_T5.js
index 3597f2c6ef..9a5fa3eb4d 100644
--- a/test/built-ins/Array/prototype/shift/S15.4.4.9_A2_T5.js
+++ b/test/built-ins/Array/prototype/shift/S15.4.4.9_A2_T5.js
@@ -16,125 +16,109 @@ obj.shift = Array.prototype.shift;
 
 obj[0] = -1;
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 1
   }
 };
 var shift = obj.shift();
-if (shift !== -1) {
-  throw new Test262Error('#1: obj[0] = -1; obj.length = {valueOf: function() {return 1}}  obj.shift() === -1. Actual: ' + (shift));
-}
+assert.sameValue(shift, -1, 'The value of shift is expected to be -1');
 
 obj[0] = -1;
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 1
   },
-  toString: function() {
+  toString() {
     return 0
   }
 };
 var shift = obj.shift();
-if (shift !== -1) {
-  throw new Test262Error('#0: obj[0] = -1; obj.length = {valueOf: function() {return 1}, toString: function() {return 0}}  obj.shift() === -1. Actual: ' + (shift));
-}
+assert.sameValue(shift, -1, 'The value of shift is expected to be -1');
 
 obj[0] = -1;
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 1
   },
-  toString: function() {
+  toString() {
     return {}
   }
 };
 var shift = obj.shift();
-if (shift !== -1) {
-  throw new Test262Error('#3: obj[0] = -1; obj.length = {valueOf: function() {return 1}, toString: function() {return {}}}  obj.shift() === -1. Actual: ' + (shift));
-}
+assert.sameValue(shift, -1, 'The value of shift is expected to be -1');
 
 try {
   obj[0] = -1;
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       return 1
     },
-    toString: function() {
+    toString() {
       throw "error"
     }
   };
   var shift = obj.shift();
-  if (shift !== -1) {
-    throw new Test262Error('#4.1: obj[0] = -1; obj.length = {valueOf: function() {return 1}, toString: function() {throw "error"}}; obj.shift() === ",". Actual: ' + (shift));
-  }
+  assert.sameValue(shift, -1, 'The value of shift is expected to be -1');
 }
 catch (e) {
-  if (e === "error") {
-    throw new Test262Error('#4.2: obj[0] = -1; obj.length = {valueOf: function() {return 1}, toString: function() {throw "error"}}; obj.shift() not throw "error"');
-  } else {
-    throw new Test262Error('#4.3: obj[0] = -1; obj.length = {valueOf: function() {return 1}, toString: function() {throw "error"}}; obj.shift() not throw Error. Actual: ' + (e));
-  }
+  assert.notSameValue(e, "error", 'The value of e is not "error"');
 }
 
 obj[0] = -1;
 obj.length = {
-  toString: function() {
+  toString() {
     return 0
   }
 };
 var shift = obj.shift();
-if (shift !== undefined) {
-  throw new Test262Error('#5: obj[0] = -1; obj.length = {toString: function() {return 0}}  obj.shift() === undefined. Actual: ' + (shift));
-}
+assert.sameValue(shift, undefined, 'The value of shift is expected to equal undefined');
 
 obj[0] = -1;
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return {}
   },
-  toString: function() {
+  toString() {
     return 0
   }
 }
 var shift = obj.shift();
-if (shift !== undefined) {
-  throw new Test262Error('#6: obj[0] = -1; obj.length = {valueOf: function() {return {}}, toString: function() {return 0}}  obj.shift() === undefined. Actual: ' + (shift));
-}
+assert.sameValue(shift, undefined, 'The value of shift is expected to equal undefined');
 
 try {
   obj[0] = -1;
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       throw "error"
     },
-    toString: function() {
+    toString() {
       return 0
     }
   };
   var shift = obj.shift();
-  throw new Test262Error('#7.1: obj[0] = -1; obj.length = {valueOf: function() {throw "error"}, toString: function() {return 0}}; obj.shift() throw "error". Actual: ' + (shift));
+  throw new Test262Error('#7.1: obj[0] = -1; obj.length = {valueOf() {throw "error"}, toString() {return 0}}; obj.shift() throw "error". Actual: ' + (shift));
 }
 catch (e) {
-  if (e !== "error") {
-    throw new Test262Error('#7.2: obj[0] = -1; obj.length = {valueOf: function() {throw "error"}, toString: function() {return 0}}; obj.shift() throw "error". Actual: ' + (e));
-  }
+  assert.sameValue(e, "error", 'The value of e is expected to be "error"');
 }
 
 try {
   obj[0] = -1;
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       return {}
     },
-    toString: function() {
+    toString() {
       return {}
     }
   };
   var shift = obj.shift();
-  throw new Test262Error('#8.1: obj[0] = -1; obj.length = {valueOf: function() {return {}}, toString: function() {return {}}}  obj.shift() throw TypeError. Actual: ' + (shift));
+  throw new Test262Error('#8.1: obj[0] = -1; obj.length = {valueOf() {return {}}, toString() {return {}}}  obj.shift() throw TypeError. Actual: ' + (shift));
 }
 catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#8.2: obj[0] = -1; obj.length = {valueOf: function() {return {}}, toString: function() {return {}}}  obj.shift() throw TypeError. Actual: ' + (e));
-  }
+  assert.sameValue(
+    e instanceof TypeError,
+    true,
+    'The result of evaluating (e instanceof TypeError) is expected to be true'
+  );
 }
diff --git a/test/built-ins/Array/prototype/shift/S15.4.4.9_A5.7.js b/test/built-ins/Array/prototype/shift/S15.4.4.9_A5.7.js
index 7b658bd2d8..ca94cddd2d 100644
--- a/test/built-ins/Array/prototype/shift/S15.4.4.9_A5.7.js
+++ b/test/built-ins/Array/prototype/shift/S15.4.4.9_A5.7.js
@@ -9,12 +9,7 @@ description: >
     throw a TypeError exception
 ---*/
 
-
-try {
+assert.throws(TypeError, () => {
   new Array.prototype.shift();
-  throw new Test262Error('#1.1: new Array.prototype.shift() throw TypeError. Actual: ' + (new Array.prototype.shift()));
-} catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#1.2: new Array.prototype.shift() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/slice/S15.4.4.10_A3_T1.js b/test/built-ins/Array/prototype/slice/S15.4.4.10_A3_T1.js
index 98d72af7a7..41df4336fd 100644
--- a/test/built-ins/Array/prototype/slice/S15.4.4.10_A3_T1.js
+++ b/test/built-ins/Array/prototype/slice/S15.4.4.10_A3_T1.js
@@ -7,17 +7,13 @@ esid: sec-array.prototype.slice
 description: length = 4294967296
 ---*/
 
-var obj = {};
-obj.slice = Array.prototype.slice;
-obj[0] = "x";
-obj[4294967295] = "y";
-obj.length = 4294967296;
-
-try {
-  var arr = obj.slice(0, 4294967296);
-  throw new Test262Error('#1: var obj = {}; obj.slice = Array.prototype.slice; obj[0] = "x"; obj[4294967295] = "y"; obj.length = 4294967296; var arr = obj.slice(0,4294967296); lead to throwing exception.');
-} catch (e) {
-  if (!(e instanceof RangeError)) {
-    throw new Test262Error('#1.1: var obj = {}; obj.slice = Array.prototype.slice; obj[0] = "x"; obj[4294967295] = "y"; obj.length = 4294967296; var arr = obj.slice(0,4294967296); lead to throwing exception. Exception is instance of RangeError. Actual: exception is ' + e);
-  }
-}
+assert.throws(RangeError, () => {
+  var obj = {};
+  obj.slice = Array.prototype.slice;
+  obj[0] = "x";
+  obj[4294967295] = "y";
+  obj.length = 4294967296;
+  obj.slice(0, 4294967296);
+  new Array.prototype.toLocaleString();
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/slice/S15.4.4.10_A3_T2.js b/test/built-ins/Array/prototype/slice/S15.4.4.10_A3_T2.js
index 0358fd0e1d..ac5d83ba18 100644
--- a/test/built-ins/Array/prototype/slice/S15.4.4.10_A3_T2.js
+++ b/test/built-ins/Array/prototype/slice/S15.4.4.10_A3_T2.js
@@ -7,17 +7,12 @@ esid: sec-array.prototype.slice
 description: length = 4294967297
 ---*/
 
-var obj = {};
-obj.slice = Array.prototype.slice;
-obj[0] = "x";
-obj[4294967296] = "y";
-obj.length = 4294967297;
-
-try {
-  var arr = obj.slice(0, 4294967297);
-  throw new Test262Error('#1: var obj = {}; obj.slice = Array.prototype.slice; obj[0] = "x"; obj[4294967296] = "y"; obj.length = 4294967297; var arr = obj.slice(0,4294967297); lead to throwing exception.');
-} catch (e) {
-  if (!(e instanceof RangeError)) {
-    throw new Test262Error('#1.1: var obj = {}; obj.slice = Array.prototype.slice; obj[0] = "x"; obj[4294967296] = "y"; obj.length = 4294967297; var arr = obj.slice(0,4294967297); lead to throwing exception. Exception is instance of RangeError. Actual: exception is ' + e);
-  }
-}
+assert.throws(RangeError, () => {
+  var obj = {};
+  obj.slice = Array.prototype.slice;
+  obj[0] = "x";
+  obj[4294967296] = "y";
+  obj.length = 4294967297;
+  obj.slice(0, 4294967297);
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/slice/S15.4.4.10_A5.7.js b/test/built-ins/Array/prototype/slice/S15.4.4.10_A5.7.js
index a3c7162296..2e65c0c075 100644
--- a/test/built-ins/Array/prototype/slice/S15.4.4.10_A5.7.js
+++ b/test/built-ins/Array/prototype/slice/S15.4.4.10_A5.7.js
@@ -9,12 +9,7 @@ description: >
     throw a TypeError exception
 ---*/
 
-
-try {
+assert.throws(TypeError, () => {
   new Array.prototype.slice();
-  throw new Test262Error('#1.1: new Array.prototype.slice() throw TypeError. Actual: ' + (new Array.prototype.slice()));
-} catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#1.2: new Array.prototype.slice() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/sort/S15.4.4.11_A5_T1.js b/test/built-ins/Array/prototype/sort/S15.4.4.11_A5_T1.js
index 1c164af479..8e0a401de1 100644
--- a/test/built-ins/Array/prototype/sort/S15.4.4.11_A5_T1.js
+++ b/test/built-ins/Array/prototype/sort/S15.4.4.11_A5_T1.js
@@ -7,15 +7,10 @@ esid: sec-array.prototype.sort
 description: comparefn function throw "error"
 ---*/
 
-var myComparefn = function(x, y) {
-  throw "error";
-}
-var x = [1, 0];
-try {
-  x.sort(myComparefn)
-  throw new Test262Error('#1.1: Array.sort should not eat exceptions');
-} catch (e) {
-  if (e !== "error") {
-    throw new Test262Error('#1.2: Array.sort should not eat exceptions');
+assert.throws(Test262Error, () => {
+  var myComparefn = function(x, y) {
+    throw new Test262Error();
   }
-}
+  var x = [1, 0];
+  x.sort(myComparefn);
+});
diff --git a/test/built-ins/Array/prototype/sort/S15.4.4.11_A7.7.js b/test/built-ins/Array/prototype/sort/S15.4.4.11_A7.7.js
index 7c7c3700a9..91b1d21453 100644
--- a/test/built-ins/Array/prototype/sort/S15.4.4.11_A7.7.js
+++ b/test/built-ins/Array/prototype/sort/S15.4.4.11_A7.7.js
@@ -9,12 +9,7 @@ description: >
     throw a TypeError exception
 ---*/
 
-
-try {
+assert.throws(TypeError, () => {
   new Array.prototype.sort();
-  throw new Test262Error('#1.1: new Array.prototype.sort() throw TypeError. Actual: ' + (new Array.prototype.sort()));
-} catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#1.2: new Array.prototype.sort() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/splice/S15.4.4.12_A5.7.js b/test/built-ins/Array/prototype/splice/S15.4.4.12_A5.7.js
index 9ab2d60c68..f4ab5911b5 100644
--- a/test/built-ins/Array/prototype/splice/S15.4.4.12_A5.7.js
+++ b/test/built-ins/Array/prototype/splice/S15.4.4.12_A5.7.js
@@ -9,12 +9,7 @@ description: >
     throw a TypeError exception
 ---*/
 
-
-try {
+assert.throws(TypeError, () => {
   new Array.prototype.splice();
-  throw new Test262Error('#1.1: new Array.prototype.splice() throw TypeError. Actual: ' + (new Array.prototype.splice()));
-} catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#1.2: new Array.prototype.splice() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/toLocaleString/S15.4.4.3_A4.7.js b/test/built-ins/Array/prototype/toLocaleString/S15.4.4.3_A4.7.js
index 41957c8ab0..1354e95aa9 100644
--- a/test/built-ins/Array/prototype/toLocaleString/S15.4.4.3_A4.7.js
+++ b/test/built-ins/Array/prototype/toLocaleString/S15.4.4.3_A4.7.js
@@ -10,12 +10,7 @@ description: >
     throw a TypeError exception
 ---*/
 
-
-try {
+assert.throws(TypeError, () => {
   new Array.prototype.toLocaleString();
-  throw new Test262Error('#1.1: new Array.prototype.toLocaleString() throw TypeError. Actual: ' + (new Array.prototype.toLocaleString()));
-} catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#1.2: new Array.prototype.toLocaleString() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/toString/S15.4.4.2_A1_T4.js b/test/built-ins/Array/prototype/toString/S15.4.4.2_A1_T4.js
index dc564c901e..661499cec4 100644
--- a/test/built-ins/Array/prototype/toString/S15.4.4.2_A1_T4.js
+++ b/test/built-ins/Array/prototype/toString/S15.4.4.2_A1_T4.js
@@ -11,144 +11,89 @@ description: If Type(value) is Object, evaluate ToPrimitive(value, String)
 ---*/
 
 var object = {
-  valueOf: function() {
+  valueOf() {
     return "+"
   }
 };
 var x = new Array(object);
-if (x.toString() !== x.join()) {
-  throw new Test262Error('#1.1: var object = {valueOf: function() {return "+"}} var x = new Array(object); x.toString() === x.join(). Actual: ' + (x.toString()));
-} else {
-  if (x.toString() !== "[object Object]") {
-    throw new Test262Error('#1.2: var object = {valueOf: function() {return "+"}} var x = new Array(object); x.toString() === "[object Object]". Actual: ' + (x.toString()));
-  }
-}
+assert.sameValue(x.toString(), x.join(), 'x.toString() must return the same value returned by x.join()');
 
 var object = {
-  valueOf: function() {
+  valueOf() {
     return "+"
   },
-  toString: function() {
+  toString() {
     return "*"
   }
 };
 var x = new Array(object);
-if (x.toString() !== x.join()) {
-  throw new Test262Error('#2.1: var object = {valueOf: function() {return "+"}, toString: function() {return x.join()}} var x = new Array(object); x.toString() === "*". Actual: ' + (x.toString()));
-} else {
-  if (x.toString() !== "*") {
-    throw new Test262Error('#2.2: var object = {valueOf: function() {return "+"}, toString: function() {return "*"}} var x = new Array(object); x.toString() === "*". Actual: ' + (x.toString()));
-  }
-}
+assert.sameValue(x.toString(), x.join(), 'x.toString() must return the same value returned by x.join()');
 
 var object = {
-  valueOf: function() {
+  valueOf() {
     return "+"
   },
-  toString: function() {
+  toString() {
     return {}
   }
 };
 var x = new Array(object);
-if (x.toString() !== x.join()) {
-  throw new Test262Error('#3.1: var object = {valueOf: function() {return x.join()}, toString: function() {return {}}} var x = new Array(object); x.toString() === "+". Actual: ' + (x.toString()));
-} else {
-  if (x.toString() !== "+") {
-    throw new Test262Error('#3.2: var object = {valueOf: function() {return "+"}, toString: function() {return {}}} var x = new Array(object); x.toString() === "+". Actual: ' + (x.toString()));
-  }
-}
-
-try {
-  var object = {
-    valueOf: function() {
-      throw "error"
-    },
-    toString: function() {
-      return "*"
-    }
-  };
-  var x = new Array(object);
-  if (x.toString() !== x.join()) {
-    throw new Test262Error('#4.1: var object = {valueOf: function() {throw "error"}, toString: function() {return x.join()}} var x = new Array(object); x.toString() === "*". Actual: ' + (x.toString()));
-  } else {
-    if (x.toString() !== "*") {
-      throw new Test262Error('#4.2: var object = {valueOf: function() {throw "error"}, toString: function() {return "*"}} var x = new Array(object); x.toString() === "*". Actual: ' + (x.toString()));
-    }
-  }
-}
-catch (e) {
-  if (e === "error") {
-    throw new Test262Error('#4.3: var object = {valueOf: function() {throw "error"}, toString: function() {return "*"}} var x = new Array(object); x.toString() not throw "error"');
-  } else {
-    throw new Test262Error('#4.4: var object = {valueOf: function() {throw "error"}, toString: function() {return "*"}} var x = new Array(object); x.toString() not throw Error. Actual: ' + (e));
-  }
-}
+assert.sameValue(x.toString(), x.join(), 'x.toString() must return the same value returned by x.join()');
 
 var object = {
-  toString: function() {
+  valueOf() {
+    throw "error"
+  },
+  toString() {
     return "*"
   }
 };
 var x = new Array(object);
-if (x.toString() !== x.join()) {
-  throw new Test262Error('#5.1: var object = {toString: function() {return x.join()}} var x = new Array(object); x.toString() === "*". Actual: ' + (x.toString()));
-} else {
-  if (x.toString() !== "*") {
-    throw new Test262Error('#5.2: var object = {toString: function() {return "*"}} var x = new Array(object); x.toString() === "*". Actual: ' + (x.toString()));
-  }
-}
+assert.sameValue(x.toString(), x.join(), 'x.toString() must return the same value returned by x.join()');
+
 
 var object = {
-  valueOf: function() {
+  toString() {
+    return "*"
+  }
+};
+var x = new Array(object);
+assert.sameValue(x.toString(), x.join(), 'x.toString() must return the same value returned by x.join()');
+
+var object = {
+  valueOf() {
     return {}
   },
-  toString: function() {
+  toString() {
     return "*"
   }
 }
 var x = new Array(object);
-if (x.toString() !== x.join()) {
-  throw new Test262Error('#6.1: var object = {valueOf: function() {return {}}, toString: function() {return x.join()}} var x = new Array(object); x.toString() === "*". Actual: ' + (x.toString()));
-} else {
-  if (x.toString() !== "*") {
-    throw new Test262Error('#6.2: var object = {valueOf: function() {return {}}, toString: function() {return "*"}} var x = new Array(object); x.toString() === "*". Actual: ' + (x.toString()));
-  }
-}
+assert.sameValue(x.toString(), x.join(), 'x.toString() must return the same value returned by x.join()');
 
-try {
+assert.throws(Test262Error, () => {
   var object = {
-    valueOf: function() {
+    valueOf() {
       return "+"
     },
-    toString: function() {
-      throw "error"
+    toString() {
+      throw new Test262Error();
     }
   };
   var x = new Array(object);
   x.toString();
-  throw new Test262Error('#7.1: var object = {valueOf: function() {return "+"}, toString: function() {throw "error"}} var x = new Array(object); x.toString() throw "error". Actual: ' + (x.toString()));
-}
-catch (e) {
-  if (e !== "error") {
-    throw new Test262Error('#7.2: var object = {valueOf: function() {return "+"}, toString: function() {throw "error"}} var x = new Array(object); x.toString() throw "error". Actual: ' + (e));
-  }
-}
+});
 
-try {
+assert.throws(TypeError, () => {
   var object = {
-    valueOf: function() {
+    valueOf() {
       return {}
     },
-    toString: function() {
+    toString() {
       return {}
     }
   };
   var x = new Array(object);
   x.toString();
-  throw new Test262Error('#8.1: var object = {valueOf: function() {return {}}, toString: function() {return {}}} var x = new Array(object); x.toString() throw TypeError. Actual: ' + (x.toString()));
-}
-catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#8.2: var object = {valueOf: function() {return {}}, toString: function() {return {}}} var x = new Array(object); x.toString() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/toString/S15.4.4.2_A4.7.js b/test/built-ins/Array/prototype/toString/S15.4.4.2_A4.7.js
index 8922c434fd..4cb290b049 100644
--- a/test/built-ins/Array/prototype/toString/S15.4.4.2_A4.7.js
+++ b/test/built-ins/Array/prototype/toString/S15.4.4.2_A4.7.js
@@ -10,12 +10,7 @@ description: >
     throw a TypeError exception
 ---*/
 
-
-try {
+assert.throws(TypeError, () => {
   new Array.prototype.toString();
-  throw new Test262Error('#1.1: new Array.prototype.toString() throw TypeError. Actual: ' + (new Array.prototype.toString()));
-} catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#1.2: new Array.prototype.toString() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});
diff --git a/test/built-ins/Array/prototype/unshift/S15.4.4.13_A2_T3.js b/test/built-ins/Array/prototype/unshift/S15.4.4.13_A2_T3.js
index 7a1da8898f..7f9ed4e247 100644
--- a/test/built-ins/Array/prototype/unshift/S15.4.4.13_A2_T3.js
+++ b/test/built-ins/Array/prototype/unshift/S15.4.4.13_A2_T3.js
@@ -15,120 +15,104 @@ var obj = {};
 obj.unshift = Array.prototype.unshift;
 
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 3
   }
 };
 var unshift = obj.unshift();
-if (unshift !== 3) {
-  throw new Test262Error('#1:  obj.length = {valueOf: function() {return 3}}  obj.unshift() === 3. Actual: ' + (unshift));
-}
+assert.sameValue(unshift, 3, 'The value of unshift is expected to be 3');
 
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 3
   },
-  toString: function() {
+  toString() {
     return 1
   }
 };
 var unshift = obj.unshift();
-if (unshift !== 3) {
-  throw new Test262Error('#0:  obj.length = {valueOf: function() {return 3}, toString: function() {return 1}}  obj.unshift() === 3. Actual: ' + (unshift));
-}
+assert.sameValue(unshift, 3, 'The value of unshift is expected to be 3');
 
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return 3
   },
-  toString: function() {
+  toString() {
     return {}
   }
 };
 var unshift = obj.unshift();
-if (unshift !== 3) {
-  throw new Test262Error('#1:  obj.length = {valueOf: function() {return 3}, toString: function() {return {}}}  obj.unshift() === 3. Actual: ' + (unshift));
-}
+assert.sameValue(unshift, 3, 'The value of unshift is expected to be 3');
 
 try {
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       return 3
     },
-    toString: function() {
+    toString() {
       throw "error"
     }
   };
   var unshift = obj.unshift();
-  if (unshift !== 3) {
-    throw new Test262Error('#4.1:  obj.length = {valueOf: function() {return 3}, toString: function() {throw "error"}}; obj.unshift() === ",". Actual: ' + (unshift));
-  }
+  assert.sameValue(unshift, 3, 'The value of unshift is expected to be 3');
 }
 catch (e) {
-  if (e === "error") {
-    throw new Test262Error('#4.2:  obj.length = {valueOf: function() {return 3}, toString: function() {throw "error"}}; obj.unshift() not throw "error"');
-  } else {
-    throw new Test262Error('#4.3:  obj.length = {valueOf: function() {return 3}, toString: function() {throw "error"}}; obj.unshift() not throw Error. Actual: ' + (e));
-  }
+  assert.notSameValue(e, "error", 'The value of e is not "error"');
 }
 
 obj.length = {
-  toString: function() {
+  toString() {
     return 1
   }
 };
 var unshift = obj.unshift();
-if (unshift !== 1) {
-  throw new Test262Error('#5:  obj.length = {toString: function() {return 1}}  obj.unshift() === 1. Actual: ' + (unshift));
-}
+assert.sameValue(unshift, 1, 'The value of unshift is expected to be 1');
 
 obj.length = {
-  valueOf: function() {
+  valueOf() {
     return {}
   },
-  toString: function() {
+  toString() {
     return 1
   }
 }
 var unshift = obj.unshift();
-if (unshift !== 1) {
-  throw new Test262Error('#6:  obj.length = {valueOf: function() {return {}}, toString: function() {return 1}}  obj.unshift() === 1. Actual: ' + (unshift));
-}
+assert.sameValue(unshift, 1, 'The value of unshift is expected to be 1');
 
 try {
 
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       throw "error"
     },
-    toString: function() {
+    toString() {
       return 1
     }
   };
   var unshift = obj.unshift();
-  throw new Test262Error('#7.1:  obj.length = {valueOf: function() {throw "error"}, toString: function() {return 1}}; obj.unshift() throw "error". Actual: ' + (unshift));
+  throw new Test262Error('#7.1:  obj.length = {valueOf() {throw "error"}, toString() {return 1}}; obj.unshift() throw "error". Actual: ' + (unshift));
 }
 catch (e) {
-  if (e !== "error") {
-    throw new Test262Error('#7.2:  obj.length = {valueOf: function() {throw "error"}, toString: function() {return 1}}; obj.unshift() throw "error". Actual: ' + (e));
-  }
+  assert.sameValue(e, "error", 'The value of e is expected to be "error"');
 }
 
 try {
 
   obj.length = {
-    valueOf: function() {
+    valueOf() {
       return {}
     },
-    toString: function() {
+    toString() {
       return {}
     }
   };
   var unshift = obj.unshift();
-  throw new Test262Error('#8.1:  obj.length = {valueOf: function() {return {}}, toString: function() {return {}}}  obj.unshift() throw TypeError. Actual: ' + (unshift));
+  throw new Test262Error('#8.1:  obj.length = {valueOf() {return {}}, toString() {return {}}}  obj.unshift() throw TypeError. Actual: ' + (unshift));
 }
 catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#8.2:  obj.length = {valueOf: function() {return {}}, toString: function() {return {}}}  obj.unshift() throw TypeError. Actual: ' + (e));
-  }
+  assert.sameValue(
+    e instanceof TypeError,
+    true,
+    'The result of evaluating (e instanceof TypeError) is expected to be true'
+  );
 }
diff --git a/test/built-ins/Array/prototype/unshift/S15.4.4.13_A5.7.js b/test/built-ins/Array/prototype/unshift/S15.4.4.13_A5.7.js
index ed3bf22d78..b133386118 100644
--- a/test/built-ins/Array/prototype/unshift/S15.4.4.13_A5.7.js
+++ b/test/built-ins/Array/prototype/unshift/S15.4.4.13_A5.7.js
@@ -9,12 +9,7 @@ description: >
     throw a TypeError exception
 ---*/
 
-
-try {
+assert.throws(TypeError, () => {
   new Array.prototype.unshift();
-  throw new Test262Error('#1.1: new Array.prototype.unshift() throw TypeError. Actual: ' + (new Array.prototype.unshift()));
-} catch (e) {
-  if ((e instanceof TypeError) !== true) {
-    throw new Test262Error('#1.2: new Array.prototype.unshift() throw TypeError. Actual: ' + (e));
-  }
-}
+  throw new Test262Error();
+});