diff --git a/test/built-ins/String/15.5.5.5.2-1-1.js b/test/built-ins/String/15.5.5.5.2-1-1.js
index 7272f6a63c..cd06724907 100644
--- a/test/built-ins/String/15.5.5.5.2-1-1.js
+++ b/test/built-ins/String/15.5.5.5.2-1-1.js
@@ -9,15 +9,10 @@ es5id: 15.5.5.5.2-1-1
 description: >
     String object supports bracket notation to lookup of data
     properties
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = new String("hello world");
   s.foo = 1;
   
-  if (s["foo"] === 1) {
-    return true;
-  }
- }
-runTestCase(testcase);
+
+assert.sameValue(s["foo"], 1, 's["foo"]');
diff --git a/test/built-ins/String/15.5.5.5.2-1-2.js b/test/built-ins/String/15.5.5.5.2-1-2.js
index 3dcb39432e..b822ef8a34 100644
--- a/test/built-ins/String/15.5.5.5.2-1-2.js
+++ b/test/built-ins/String/15.5.5.5.2-1-2.js
@@ -7,14 +7,9 @@ info: >
     notation to look up non numeric property names.
 es5id: 15.5.5.5.2-1-2
 description: String value supports bracket notation to lookup data properties
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = String("hello world");
   
-  if (s["foo"] === undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+
+assert.sameValue(s["foo"], undefined, 's["foo"]');
diff --git a/test/built-ins/String/15.5.5.5.2-3-1.js b/test/built-ins/String/15.5.5.5.2-3-1.js
index 0329088abb..b6d265f38f 100644
--- a/test/built-ins/String/15.5.5.5.2-3-1.js
+++ b/test/built-ins/String/15.5.5.5.2-3-1.js
@@ -9,14 +9,9 @@ es5id: 15.5.5.5.2-3-1
 description: >
     String object indexing returns undefined for missing data
     properties
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = new String("hello world");
   
-  if (s["foo"] === undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+
+assert.sameValue(s["foo"], undefined, 's["foo"]');
diff --git a/test/built-ins/String/15.5.5.5.2-3-2.js b/test/built-ins/String/15.5.5.5.2-3-2.js
index 6448d6bbc6..91e1b7609a 100644
--- a/test/built-ins/String/15.5.5.5.2-3-2.js
+++ b/test/built-ins/String/15.5.5.5.2-3-2.js
@@ -7,14 +7,9 @@ info: >
     notation to look up non numeric property names.
 es5id: 15.5.5.5.2-3-2
 description: String value indexing returns undefined for missing data properties
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = String("hello world");
   
-  if (s["foo"] === undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+
+assert.sameValue(s["foo"], undefined, 's["foo"]');
diff --git a/test/built-ins/String/15.5.5.5.2-3-3.js b/test/built-ins/String/15.5.5.5.2-3-3.js
index 1a3278dd75..73df524aee 100644
--- a/test/built-ins/String/15.5.5.5.2-3-3.js
+++ b/test/built-ins/String/15.5.5.5.2-3-3.js
@@ -9,14 +9,8 @@ es5id: 15.5.5.5.2-3-3
 description: >
     String object indexing returns undefined if the numeric index
     (NaN) is not an array index
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = new String("hello world");
 
-  if (s[NaN] === undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(s[NaN], undefined, 's[NaN]');
diff --git a/test/built-ins/String/15.5.5.5.2-3-4.js b/test/built-ins/String/15.5.5.5.2-3-4.js
index 85feb226c1..3f1a038b18 100644
--- a/test/built-ins/String/15.5.5.5.2-3-4.js
+++ b/test/built-ins/String/15.5.5.5.2-3-4.js
@@ -9,14 +9,8 @@ es5id: 15.5.5.5.2-3-4
 description: >
     String object indexing returns undefined if the numeric index
     (Infinity) is not an array index
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = new String("hello world");
 
-  if (s[Infinity] === undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(s[Infinity], undefined, 's[Infinity]');
diff --git a/test/built-ins/String/15.5.5.5.2-3-5.js b/test/built-ins/String/15.5.5.5.2-3-5.js
index 5ae4f23c58..a58b645b2d 100644
--- a/test/built-ins/String/15.5.5.5.2-3-5.js
+++ b/test/built-ins/String/15.5.5.5.2-3-5.js
@@ -9,14 +9,8 @@ es5id: 15.5.5.5.2-3-5
 description: >
     String object indexing returns undefined if the numeric index (
     2^32-1) is not an array index
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = new String("hello world");
 
-  if (s[Math.pow(2, 32)-1]===undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(s[Math.pow(2, 32)-1], undefined, 's[Math.pow(2, 32)-1]');
diff --git a/test/built-ins/String/15.5.5.5.2-3-6.js b/test/built-ins/String/15.5.5.5.2-3-6.js
index 05d266aa98..a285440358 100644
--- a/test/built-ins/String/15.5.5.5.2-3-6.js
+++ b/test/built-ins/String/15.5.5.5.2-3-6.js
@@ -9,14 +9,8 @@ es5id: 15.5.5.5.2-3-6
 description: >
     String value indexing returns undefined if the numeric index (NaN)
     is not an array index
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = String("hello world");
 
-  if (s[NaN] === undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(s[NaN], undefined, 's[NaN]');
diff --git a/test/built-ins/String/15.5.5.5.2-3-7.js b/test/built-ins/String/15.5.5.5.2-3-7.js
index 4423b89ce0..ff60fbccb0 100644
--- a/test/built-ins/String/15.5.5.5.2-3-7.js
+++ b/test/built-ins/String/15.5.5.5.2-3-7.js
@@ -9,14 +9,8 @@ es5id: 15.5.5.5.2-3-7
 description: >
     String value indexing returns undefined if the numeric index
     (Infinity) is not an array index
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = String("hello world");
 
-  if (s[Infinity] === undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(s[Infinity], undefined, 's[Infinity]');
diff --git a/test/built-ins/String/15.5.5.5.2-3-8.js b/test/built-ins/String/15.5.5.5.2-3-8.js
index a768680780..e7eb2d0851 100644
--- a/test/built-ins/String/15.5.5.5.2-3-8.js
+++ b/test/built-ins/String/15.5.5.5.2-3-8.js
@@ -9,14 +9,8 @@ es5id: 15.5.5.5.2-3-8
 description: >
     String value indexing returns undefined if the numeric index ( >=
     2^32-1) is not an array index
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = String("hello world");
 
-  if (s[Math.pow(2, 32)-1]===undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(s[Math.pow(2, 32)-1], undefined, 's[Math.pow(2, 32)-1]');
diff --git a/test/built-ins/String/15.5.5.5.2-7-1.js b/test/built-ins/String/15.5.5.5.2-7-1.js
index b43a7fcd9a..2b4f2493d6 100644
--- a/test/built-ins/String/15.5.5.5.2-7-1.js
+++ b/test/built-ins/String/15.5.5.5.2-7-1.js
@@ -9,14 +9,8 @@ es5id: 15.5.5.5.2-7-1
 description: >
     String object indexing returns undefined if the numeric index is
     less than 0
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = new String("hello world");
 
-  if (s[-1] === undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(s[-1], undefined, 's[-1]');
diff --git a/test/built-ins/String/15.5.5.5.2-7-2.js b/test/built-ins/String/15.5.5.5.2-7-2.js
index df78c9415d..1bf9c632a9 100644
--- a/test/built-ins/String/15.5.5.5.2-7-2.js
+++ b/test/built-ins/String/15.5.5.5.2-7-2.js
@@ -9,14 +9,8 @@ es5id: 15.5.5.5.2-7-2
 description: >
     String value indexing returns undefined if the numeric index is
     less than 0
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = String("hello world");
 
-  if (s[-1] === undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(s[-1], undefined, 's[-1]');
diff --git a/test/built-ins/String/15.5.5.5.2-7-3.js b/test/built-ins/String/15.5.5.5.2-7-3.js
index eb03d28d14..66d60ac03b 100644
--- a/test/built-ins/String/15.5.5.5.2-7-3.js
+++ b/test/built-ins/String/15.5.5.5.2-7-3.js
@@ -9,14 +9,8 @@ es5id: 15.5.5.5.2-7-3
 description: >
     String object indexing returns undefined if the numeric index is
     greater than the string length
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = new String("hello world");
 
-  if (s[11] === undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(s[11], undefined, 's[11]');
diff --git a/test/built-ins/String/15.5.5.5.2-7-4.js b/test/built-ins/String/15.5.5.5.2-7-4.js
index b13a09df56..1d06e8d9d4 100644
--- a/test/built-ins/String/15.5.5.5.2-7-4.js
+++ b/test/built-ins/String/15.5.5.5.2-7-4.js
@@ -9,14 +9,8 @@ es5id: 15.5.5.5.2-7-4
 description: >
     String value indexing returns undefined if the numeric index is
     greater than the string length
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = String("hello world");
 
-  if (s[11] === undefined) {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(s[11], undefined, 's[11]');
diff --git a/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Fail.js b/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Fail.js
index 5b9b365cd2..6a9ee85854 100644
--- a/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Fail.js
+++ b/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Fail.js
@@ -4,13 +4,7 @@
 /*---
 author: Ryan Lewis
 description: endsWith should return false when called on 'word' and passed 'r'.
-includes: [runTestCase.js]
 features: [String#endsWith]
 ---*/
 
-function testcase() {
-  if('word'.endsWith('r') === false) {
-  	return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue('word'.endsWith('r'), false, '"word".endsWith("r")');
diff --git a/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Fail_2.js b/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Fail_2.js
index 19954e1cfa..0b34a7b410 100644
--- a/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Fail_2.js
+++ b/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Fail_2.js
@@ -6,13 +6,7 @@ author: Ryan Lewis
 description: >
     endsWith should return false when called on 'word' and passed 'd',
     with an endPosition of 3.
-includes: [runTestCase.js]
 features: [String#endsWith]
 ---*/
 
-function testcase() {
-  if('word'.endsWith('d', 3) === false) {
-  	return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue('word'.endsWith('d', 3), false, '"word".endsWith("d", 3)');
diff --git a/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success.js b/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success.js
index b3655ff81d..854bc56eed 100644
--- a/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success.js
+++ b/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success.js
@@ -6,13 +6,7 @@ author: Ryan Lewis
 description: >
     endsWith should return true when called on 'word' and passed 'd'
     and with no endPosition (defaults to 4).
-includes: [runTestCase.js]
 features: [String#endsWith]
 ---*/
 
-function testcase() {
-  if('word'.endsWith('d') === true) {
-  	return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue('word'.endsWith('d'), true, '"word".endsWith("d")');
diff --git a/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success_2.js b/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success_2.js
index 1e5f5b55e9..23aba85a2f 100644
--- a/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success_2.js
+++ b/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success_2.js
@@ -6,13 +6,7 @@ author: Ryan Lewis
 description: >
     endsWith should return true when called on 'word' and passed 'd'
     and with an endPosition of 4.
-includes: [runTestCase.js]
 features: [String#endsWith]
 ---*/
 
-function testcase() {
-  if('word'.endsWith('d', 4) === true) {
-  	return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue('word'.endsWith('d', 4), true, '"word".endsWith("d", 4)');
diff --git a/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success_3.js b/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success_3.js
index 13613026c8..0b8ceae787 100644
--- a/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success_3.js
+++ b/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success_3.js
@@ -6,13 +6,7 @@ author: Ryan Lewis
 description: >
     endsWith should return true when called on 'word' and passed 'd'
     and with an endPosition of 25.
-includes: [runTestCase.js]
 features: [String#endsWith]
 ---*/
 
-function testcase() {
-  if('word'.endsWith('d', 25) === true) {
-  	return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue('word'.endsWith('d', 25), true, '"word".endsWith("d", 25)');
diff --git a/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success_4.js b/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success_4.js
index 47147e79ba..5318ce43fd 100644
--- a/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success_4.js
+++ b/test/built-ins/String/prototype/endsWith/String.prototype.endsWith_Success_4.js
@@ -6,13 +6,7 @@ author: Ryan Lewis
 description: >
     endsWith should return true when called on 'word' and passed 'r',
     with an endPosition of 3.
-includes: [runTestCase.js]
 features: [String#endsWith]
 ---*/
 
-function testcase() {
-  if('word'.endsWith('r', 3) === true) {
-  	return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue('word'.endsWith('r', 3), true, '"word".endsWith("r", 3)');
diff --git a/test/built-ins/String/prototype/includes/String.prototype.includes_FailBadLocation.js b/test/built-ins/String/prototype/includes/String.prototype.includes_FailBadLocation.js
index 0606dd1f08..b98ebe9f55 100644
--- a/test/built-ins/String/prototype/includes/String.prototype.includes_FailBadLocation.js
+++ b/test/built-ins/String/prototype/includes/String.prototype.includes_FailBadLocation.js
@@ -6,13 +6,7 @@ author: Ryan Lewis
 description: >
     String should return false if a location is passed that is
     greather than the length of the string.
-includes: [runTestCase.js]
 features: [String#includes]
 ---*/
 
-function testcase() {
-  if('word'.includes('w', 5) === false) {
-  	return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue('word'.includes('w', 5), false, '"word".includes("w", 5)');
diff --git a/test/built-ins/String/prototype/includes/String.prototype.includes_FailLocation.js b/test/built-ins/String/prototype/includes/String.prototype.includes_FailLocation.js
index dbd28ae96b..c787bb81aa 100644
--- a/test/built-ins/String/prototype/includes/String.prototype.includes_FailLocation.js
+++ b/test/built-ins/String/prototype/includes/String.prototype.includes_FailLocation.js
@@ -6,13 +6,7 @@ author: Ryan Lewis
 description: >
     String should return false if a letter is not found in the word
     starting from the passed location.
-includes: [runTestCase.js]
 features: [String#includes]
 ---*/
 
-function testcase() {
-  if('word'.includes('o', 3) === false) {
-  	return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue('word'.includes('o', 3), false, '"word".includes("o", 3)');
diff --git a/test/built-ins/String/prototype/includes/String.prototype.includes_FailMissingLetter.js b/test/built-ins/String/prototype/includes/String.prototype.includes_FailMissingLetter.js
index 823971eada..5e468b27f6 100644
--- a/test/built-ins/String/prototype/includes/String.prototype.includes_FailMissingLetter.js
+++ b/test/built-ins/String/prototype/includes/String.prototype.includes_FailMissingLetter.js
@@ -4,13 +4,7 @@
 /*---
 author: Ryan Lewis
 description: String should return false if a letter is not found in the word.
-includes: [runTestCase.js]
 features: [String#includes]
 ---*/
 
-function testcase() {
-  if('word'.includes('a', 0) === false) {
-  	return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue('word'.includes('a', 0), false, '"word".includes("a", 0)');
diff --git a/test/built-ins/String/prototype/includes/String.prototype.includes_Success.js b/test/built-ins/String/prototype/includes/String.prototype.includes_Success.js
index 2f2635081a..cf71285b57 100644
--- a/test/built-ins/String/prototype/includes/String.prototype.includes_Success.js
+++ b/test/built-ins/String/prototype/includes/String.prototype.includes_Success.js
@@ -6,13 +6,7 @@ author: Ryan Lewis
 description: >
     String should return true when called on 'word' and passed 'w' and
     the location 0.
-includes: [runTestCase.js]
 features: [String#includes]
 ---*/
 
-function testcase() {
-  if('word'.includes('w', 0) === true) {
-  	return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue('word'.includes('w', 0), true, '"word".includes("w", 0)');
diff --git a/test/built-ins/String/prototype/includes/String.prototype.includes_SuccessNoLocation.js b/test/built-ins/String/prototype/includes/String.prototype.includes_SuccessNoLocation.js
index 76561aef32..3128b0100f 100644
--- a/test/built-ins/String/prototype/includes/String.prototype.includes_SuccessNoLocation.js
+++ b/test/built-ins/String/prototype/includes/String.prototype.includes_SuccessNoLocation.js
@@ -6,13 +6,7 @@ author: Ryan Lewis
 description: >
     String should return true when called on 'word' and passed 'w' and
     with no location (defaults to 0).
-includes: [runTestCase.js]
 features: [String#includes]
 ---*/
 
-function testcase() {
-  if('word'.includes('w') === true) {
-  	return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue('word'.includes('w'), true, '"word".includes("w")');
diff --git a/test/built-ins/String/prototype/includes/String.prototype.includes_lengthProp.js b/test/built-ins/String/prototype/includes/String.prototype.includes_lengthProp.js
index 1f15731440..999c8fc88b 100644
--- a/test/built-ins/String/prototype/includes/String.prototype.includes_lengthProp.js
+++ b/test/built-ins/String/prototype/includes/String.prototype.includes_lengthProp.js
@@ -4,13 +4,7 @@
 /*---
 author: Ryan Lewis
 description: String should have the property length with size of 1.
-includes: [runTestCase.js]
 features: [String#includes]
 ---*/
 
-function testcase() {
-  if('word'.includes.length === 1) {
-  	return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue('word'.includes.length, 1, '"word".includes.length');
diff --git a/test/built-ins/String/prototype/replace/15.5.4.11-1.js b/test/built-ins/String/prototype/replace/15.5.4.11-1.js
index 4b736662f4..7d337df78f 100644
--- a/test/built-ins/String/prototype/replace/15.5.4.11-1.js
+++ b/test/built-ins/String/prototype/replace/15.5.4.11-1.js
@@ -7,12 +7,9 @@ description: >
     'this' object used by the replaceValue function of a
     String.prototype.replace invocation
 flags: [noStrict]
-includes:
-    - runTestCase.js
-    - fnGlobalObject.js
+includes: [fnGlobalObject.js]
 ---*/
 
-function testcase() {
   var retVal = 'x'.replace(/x/, 
                            function() { 
                                if (this===fnGlobalObject()) {
@@ -21,6 +18,5 @@ function testcase() {
                                    return 'z';
                                }
                            });
-  return retVal==='y';
-}
-runTestCase(testcase);
+
+assert.sameValue(retVal, 'y', 'retVal');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-0-1.js b/test/built-ins/String/prototype/trim/15.5.4.20-0-1.js
index 3679dbb4e2..429a17b072 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-0-1.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-0-1.js
@@ -4,13 +4,8 @@
 /*---
 es5id: 15.5.4.20-0-1
 description: String.prototype.trim must exist as a function
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var f = String.prototype.trim;
-  if (typeof(f) === "function") {
-    return true;
-  }
- }
-runTestCase(testcase);
+
+assert.sameValue(typeof(f), "function", 'typeof(f)');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-0-2.js b/test/built-ins/String/prototype/trim/15.5.4.20-0-2.js
index 35ee4c7226..61b702e346 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-0-2.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-0-2.js
@@ -4,12 +4,6 @@
 /*---
 es5id: 15.5.4.20-0-2
 description: String.prototype.trim must exist as a function taking 0 parameters
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if (String.prototype.trim.length === 0) {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(String.prototype.trim.length, 0, 'String.prototype.trim.length');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-1-8.js b/test/built-ins/String/prototype/trim/15.5.4.20-1-8.js
index dc48907384..3b93eb1737 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-1-8.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-1-8.js
@@ -6,11 +6,9 @@ es5id: 15.5.4.20-1-8
 description: >
     String.prototype.trim works for a primitive string (value is '
     abc')
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var strObj = String("    abc");
-        return "abc" === strObj.trim() && strObj.toString() === "    abc";
-    }
-runTestCase(testcase);
+
+assert.sameValue(strObj.trim(), "abc", 'strObj.trim()');
+assert.sameValue(strObj.toString(), "    abc", 'strObj.toString()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-1-9.js b/test/built-ins/String/prototype/trim/15.5.4.20-1-9.js
index 176e584610..cd09927dd8 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-1-9.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-1-9.js
@@ -6,11 +6,8 @@ es5id: 15.5.4.20-1-9
 description: >
     String.prototype.trim works for a String object which value is
     undefined
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var strObj = new String(undefined);
-        return strObj.trim() === "undefined";
-    }
-runTestCase(testcase);
+
+assert.sameValue(strObj.trim(), "undefined", 'strObj.trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-2-38.js b/test/built-ins/String/prototype/trim/15.5.4.20-2-38.js
index 40f3230e98..163254129a 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-2-38.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-2-38.js
@@ -6,16 +6,12 @@ es5id: 15.5.4.20-2-38
 description: >
     String.prototype.trim - 'this' is an object which has an own
     toString method
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var obj = {
             toString: function () {
                 return "abc";
             }
         };
 
-        return (String.prototype.trim.call(obj) === "abc");
-    }
-runTestCase(testcase);
+assert.sameValue(String.prototype.trim.call(obj), "abc", 'String.prototype.trim.call(obj)');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-2-39.js b/test/built-ins/String/prototype/trim/15.5.4.20-2-39.js
index 23442c8caa..2536716ded 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-2-39.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-2-39.js
@@ -6,16 +6,12 @@ es5id: 15.5.4.20-2-39
 description: >
     String.prototype.trim - 'this' is an object which has an own
     valueOf method
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var obj = {
             valueOf: function () {
                 return "abc";
             }
         };
 
-        return (String.prototype.trim.call(obj) === "[object Object]");
-    }
-runTestCase(testcase);
+assert.sameValue(String.prototype.trim.call(obj), "[object Object]", 'String.prototype.trim.call(obj)');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-2-40.js b/test/built-ins/String/prototype/trim/15.5.4.20-2-40.js
index e4ba7845e2..4edb83c727 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-2-40.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-2-40.js
@@ -7,10 +7,8 @@ description: >
     String.prototype.trim - 'this' is an object that has an own
     toString method that returns an object and valueOf method that
     returns a primitive value
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var toStringAccessed = false;
         var valueOfAccessed = false;
         var obj = {
@@ -23,6 +21,7 @@ function testcase() {
                 return "abc";
             }
         };
-        return (String.prototype.trim.call(obj) === "abc") && valueOfAccessed && toStringAccessed;
-    }
-runTestCase(testcase);
+
+assert.sameValue(String.prototype.trim.call(obj), "abc", 'String.prototype.trim.call(obj)');
+assert(valueOfAccessed, 'valueOfAccessed !== true');
+assert(toStringAccessed, 'toStringAccessed !== true');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-2-41.js b/test/built-ins/String/prototype/trim/15.5.4.20-2-41.js
index 98d1320055..a9233a47d1 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-2-41.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-2-41.js
@@ -6,10 +6,8 @@ es5id: 15.5.4.20-2-41
 description: >
     String.prototype.trim - 'this' is an object which has an own
     toString and valueOf method.
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var toStringAccessed = false;
         var valueOfAccessed = false;
         var obj = {
@@ -22,6 +20,7 @@ function testcase() {
                 return "cef";
             }
         };
-        return (String.prototype.trim.call(obj) === "abc") && !valueOfAccessed && toStringAccessed;
-    }
-runTestCase(testcase);
+
+assert.sameValue(String.prototype.trim.call(obj), "abc", 'String.prototype.trim.call(obj)');
+assert.sameValue(valueOfAccessed, false, 'valueOfAccessed');
+assert(toStringAccessed, 'toStringAccessed !== true');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-2-43.js b/test/built-ins/String/prototype/trim/15.5.4.20-2-43.js
index 238944ac27..1c9446bdc0 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-2-43.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-2-43.js
@@ -7,11 +7,8 @@ description: >
     String.prototype.trim - 'this' is an object with an own valueOf
     and inherited toString methods with hint string, verify inherited
     toString method will be called first
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-
         var toStringAccessed = false;
         var valueOfAccessed = false;
 
@@ -30,6 +27,7 @@ function testcase() {
             valueOfAccessed = true;
             return "efg";
         };
-        return (String.prototype.trim.call(child) === "abc") && toStringAccessed && !valueOfAccessed;
-    }
-runTestCase(testcase);
+
+assert.sameValue(String.prototype.trim.call(child), "abc", 'String.prototype.trim.call(child)');
+assert(toStringAccessed, 'toStringAccessed !== true');
+assert.sameValue(valueOfAccessed, false, 'valueOfAccessed');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-2-44.js b/test/built-ins/String/prototype/trim/15.5.4.20-2-44.js
index a4aa431f8d..3dbead7888 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-2-44.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-2-44.js
@@ -6,11 +6,8 @@ es5id: 15.5.4.20-2-44
 description: >
     String.prototype.trim - 'this' is a string that contains east
     Asian characters (value is 'SD咕噜')
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var str = "SD咕噜";
-        return str.trim() === str;
-    }
-runTestCase(testcase);
+
+assert.sameValue(str.trim(), str, 'str.trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-2-45.js b/test/built-ins/String/prototype/trim/15.5.4.20-2-45.js
index 1ac68b4ce8..c8c99d70a5 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-2-45.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-2-45.js
@@ -6,12 +6,9 @@ es5id: 15.5.4.20-2-45
 description: >
     String.prototype.trim - 'this' is a string that contains white
     space, character, number, object and null characters
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var str = "abc" + "   " + 123 + "   " + {} + "    " + "\u0000";
         var str1 = "    " + str + "    ";
-        return str1.trim() === str;
-    }
-runTestCase(testcase);
+
+assert.sameValue(str1.trim(), str, 'str1.trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-2-46.js b/test/built-ins/String/prototype/trim/15.5.4.20-2-46.js
index ed896250a1..f68088fa36 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-2-46.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-2-46.js
@@ -6,11 +6,8 @@ es5id: 15.5.4.20-2-46
 description: >
     String.prototype.trim - 'this' is a Function Object that converts
     to a string
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var funObj = function () { return arguments; };
-        return typeof(String.prototype.trim.call(funObj)) === "string";
-    }
-runTestCase(testcase);
+
+assert.sameValue(typeof(String.prototype.trim.call(funObj)), "string", 'typeof(String.prototype.trim.call(funObj))');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-2-49.js b/test/built-ins/String/prototype/trim/15.5.4.20-2-49.js
index bc4ad97fbc..7eb3a04b37 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-2-49.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-2-49.js
@@ -6,11 +6,8 @@ es5id: 15.5.4.20-2-49
 description: >
     String.prototype.trim - 'this' is a RegExp Object that converts to
     a string
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var regObj = new RegExp(/test/);
-        return String.prototype.trim.call(regObj) === "/test/";
-    }
-runTestCase(testcase);
+
+assert.sameValue(String.prototype.trim.call(regObj), "/test/", 'String.prototype.trim.call(regObj)');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-2-50.js b/test/built-ins/String/prototype/trim/15.5.4.20-2-50.js
index da4c2d4dfd..7dff7b940f 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-2-50.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-2-50.js
@@ -6,11 +6,8 @@ es5id: 15.5.4.20-2-50
 description: >
     String.prototype.trim - 'this' is a Error Object that converts to
     a string
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var errObj = new Error("test");
-        return String.prototype.trim.call(errObj) === "Error: test";
-    }
-runTestCase(testcase);
+
+assert.sameValue(String.prototype.trim.call(errObj), "Error: test", 'String.prototype.trim.call(errObj)');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-2-51.js b/test/built-ins/String/prototype/trim/15.5.4.20-2-51.js
index 1f069f0ada..d47c31beb8 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-2-51.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-2-51.js
@@ -6,11 +6,8 @@ es5id: 15.5.4.20-2-51
 description: >
     String.prototype.trim - 'this' is a Arguments Object that converts
     to a string
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var argObj = function () { return arguments; } (1, 2, true);
-        return String.prototype.trim.call(argObj) === "[object Arguments]";
-    }
-runTestCase(testcase);
+
+assert.sameValue(String.prototype.trim.call(argObj), "[object Arguments]", 'String.prototype.trim.call(argObj)');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-3-1.js b/test/built-ins/String/prototype/trim/15.5.4.20-3-1.js
index 66029872e5..0d7794575a 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-3-1.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-3-1.js
@@ -4,12 +4,8 @@
 /*---
 es5id: 15.5.4.20-3-1
 description: String.prototype.trim - 'S' is a string with all LineTerminator
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-
         var lineTerminatorsStr = "\u000A\u000D\u2028\u2029";
-        return (lineTerminatorsStr.trim() === "");
-    }
-runTestCase(testcase);
+
+assert.sameValue(lineTerminatorsStr.trim(), "", 'lineTerminatorsStr.trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-3-2.js b/test/built-ins/String/prototype/trim/15.5.4.20-3-2.js
index 8b51fb737c..6be919fc02 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-3-2.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-3-2.js
@@ -4,12 +4,8 @@
 /*---
 es5id: 15.5.4.20-3-2
 description: String.prototype.trim - 'S' is a string with all WhiteSpace
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-
         var whiteSpacesStr = "\u0009\u000A\u000B\u000C\u000D\u0020\u00A0\u1680\u180E\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200A\u2028\u2029\u202F\u205F\u3000\uFEFF";
-        return (whiteSpacesStr.trim() === "");
-    }
-runTestCase(testcase);
+
+assert.sameValue(whiteSpacesStr.trim(), "", 'whiteSpacesStr.trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-3-3.js b/test/built-ins/String/prototype/trim/15.5.4.20-3-3.js
index a9f690d07b..94f9121bcb 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-3-3.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-3-3.js
@@ -6,14 +6,10 @@ es5id: 15.5.4.20-3-3
 description: >
     String.prototype.trim - 'S' is a string with all union of
     WhiteSpace and LineTerminator
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var lineTerminatorsStr = "\u000A\u000D\u2028\u2029";
         var whiteSpacesStr = "\u0009\u000A\u000B\u000C\u000D\u0020\u00A0\u1680\u180E\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200A\u2028\u2029\u202F\u205F\u3000\uFEFF";
         var str = whiteSpacesStr + lineTerminatorsStr;
 
-        return (str.trim() === "");
-    }
-runTestCase(testcase);
+assert.sameValue(str.trim(), "", 'str.trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-3-4.js b/test/built-ins/String/prototype/trim/15.5.4.20-3-4.js
index 453c1a4513..a00b8ee11d 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-3-4.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-3-4.js
@@ -6,14 +6,10 @@ es5id: 15.5.4.20-3-4
 description: >
     String.prototype.trim - 'S' is a string start with union of all
     LineTerminator and all WhiteSpace
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var lineTerminatorsStr = "\u000A\u000D\u2028\u2029";
         var whiteSpacesStr = "\u0009\u000A\u000B\u000C\u000D\u0020\u00A0\u1680\u180E\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200A\u2028\u2029\u202F\u205F\u3000\uFEFF";
         var str = whiteSpacesStr + lineTerminatorsStr + "abc";
 
-        return (str.trim() === "abc");
-    }
-runTestCase(testcase);
+assert.sameValue(str.trim(), "abc", 'str.trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-3-5.js b/test/built-ins/String/prototype/trim/15.5.4.20-3-5.js
index e8263207b1..c13159165a 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-3-5.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-3-5.js
@@ -6,14 +6,10 @@ es5id: 15.5.4.20-3-5
 description: >
     String.prototype.trim - 'S' is a string end with union of all
     LineTerminator and all WhiteSpace
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var lineTerminatorsStr = "\u000A\u000D\u2028\u2029";
         var whiteSpacesStr = "\u0009\u000A\u000B\u000C\u000D\u0020\u00A0\u1680\u180E\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200A\u2028\u2029\u202F\u205F\u3000\uFEFF";
         var str = "abc" + whiteSpacesStr + lineTerminatorsStr ;
 
-        return (str.trim() === "abc");
-    }
-runTestCase(testcase);
+assert.sameValue(str.trim(), "abc", 'str.trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-3-6.js b/test/built-ins/String/prototype/trim/15.5.4.20-3-6.js
index 145238d45b..875d3357bb 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-3-6.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-3-6.js
@@ -7,14 +7,10 @@ description: >
     String.prototype.trim - 'S' is a string start with union of all
     LineTerminator and all WhiteSpace and end with union of all
     LineTerminator and all WhiteSpace
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var lineTerminatorsStr = "\u000A\u000D\u2028\u2029";
         var whiteSpacesStr = "\u0009\u000A\u000B\u000C\u000D\u0020\u00A0\u1680\u180E\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200A\u2028\u2029\u202F\u205F\u3000\uFEFF";
         var str = whiteSpacesStr + lineTerminatorsStr + "abc" + whiteSpacesStr + lineTerminatorsStr;
 
-        return (str.trim() === "abc");
-    }
-runTestCase(testcase);
+assert.sameValue(str.trim(), "abc", 'str.trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-3-7.js b/test/built-ins/String/prototype/trim/15.5.4.20-3-7.js
index f8b7a4f960..65b0439f22 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-3-7.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-3-7.js
@@ -6,14 +6,10 @@ es5id: 15.5.4.20-3-7
 description: >
     String.prototype.trim - 'S' is a string that union of
     LineTerminator and WhiteSpace in the middle
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var lineTerminatorsStr = "\u000A\u000D\u2028\u2029";
         var whiteSpacesStr = "\u0009\u000A\u000B\u000C\u000D\u0020\u00A0\u1680\u180E\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200A\u2028\u2029\u202F\u205F\u3000\uFEFF";
         var str = "ab" + whiteSpacesStr + lineTerminatorsStr + "cd";
 
-        return (str.trim() === str);
-    }
-runTestCase(testcase);
+assert.sameValue(str.trim(), str, 'str.trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-1.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-1.js
index 8064c5780b..9abc0fdfad 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-1.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-1.js
@@ -6,16 +6,11 @@ es5id: 15.5.4.20-4-1
 description: >
     String.prototype.trim handles multiline string with whitepace and
     lineterminators
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
 var s = "\u0009a b\
 c \u0009"
 
             
-  if (s.trim() === "a bc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+
+assert.sameValue(s.trim(), "a bc", 's.trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-11.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-11.js
index e8f88f47e4..f7e0b26447 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-11.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-11.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-11
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (abc\u0009)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("abc\u0009".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("abc\u0009".trim(), "abc", '"abc\u0009".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-12.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-12.js
index a2f335d8db..3caef65790 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-12.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-12.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-12
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (abc\u000B)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("abc\u000B".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("abc\u000B".trim(), "abc", '"abc\u000B".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-13.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-13.js
index a578d38fdf..234b364ca4 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-13.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-13.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-13
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (abc\u000C)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("abc\u000C".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("abc\u000C".trim(), "abc", '"abc\u000C".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-14.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-14.js
index 6056f3f67f..251f1c1ed0 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-14.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-14.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-14
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (abc\u0020)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("abc\u0020".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("abc\u0020".trim(), "abc", '"abc\u0020".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-16.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-16.js
index 5e4786665d..756aad46c5 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-16.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-16.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-16
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (abc\u00A0)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("abc\u00A0".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("abc\u00A0".trim(), "abc", '"abc\u00A0".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-19.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-19.js
index ebbfc69d2b..6bffa4d109 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-19.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-19.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-19
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u0009abc\u0009)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u0009abc\u0009".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u0009abc\u0009".trim(), "abc", '"\u0009abc\u0009".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-2.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-2.js
index 2072a27bd5..62adbfd550 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-2.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-2.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-2
 description: >
     String.prototype.trim handles whitepace and lineterminators (
     \u0009abc \u0009)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if (" \u0009abc \u0009".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue(" \u0009abc \u0009".trim(), "abc", '" \u0009abc \u0009".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-20.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-20.js
index 60b9543b4c..04e8e11cd8 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-20.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-20.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-20
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u000Babc\u000B)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u000Babc\u000B".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u000Babc\u000B".trim(), "abc", '"\u000Babc\u000B".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-21.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-21.js
index e39c4ac26f..033f14ba53 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-21.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-21.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-21
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u000Cabc\u000C)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u000Cabc\u000C".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u000Cabc\u000C".trim(), "abc", '"\u000Cabc\u000C".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-22.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-22.js
index 032ac8beaf..4007e5afdc 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-22.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-22.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-22
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u0020abc\u0020)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u0020abc\u0020".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u0020abc\u0020".trim(), "abc", '"\u0020abc\u0020".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-24.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-24.js
index b9ccbe1545..2997d65015 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-24.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-24.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-24
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u00A0abc\u00A0)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u00A0abc\u00A0".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u00A0abc\u00A0".trim(), "abc", '"\u00A0abc\u00A0".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-27.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-27.js
index a3648a57ac..0b9d1f0188 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-27.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-27.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-27
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u0009\u0009)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u0009\u0009".trim() === "") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u0009\u0009".trim(), "", '"\u0009\u0009".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-28.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-28.js
index 976fd7fb8d..7b2643f17b 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-28.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-28.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-28
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u000B\u000B)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u000B\u000B".trim() === "") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u000B\u000B".trim(), "", '"\u000B\u000B".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-29.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-29.js
index 6cebbd89ea..8f40a82f75 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-29.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-29.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-29
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u000C\u000C)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u000C\u000C".trim() === "") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u000C\u000C".trim(), "", '"\u000C\u000C".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-3.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-3.js
index 93f0eb87cf..b91223a8ba 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-3.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-3.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-3
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u0009abc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u0009abc".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u0009abc".trim(), "abc", '"\u0009abc".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-30.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-30.js
index 3a0cb4de6f..2219e34c72 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-30.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-30.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-30
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u0020\u0020)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u0020\u0020".trim() === "") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u0020\u0020".trim(), "", '"\u0020\u0020".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-32.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-32.js
index d7b0d193ea..142ace5439 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-32.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-32.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-32
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u00A0\u00A0)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u00A0\u00A0".trim() === "") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u00A0\u00A0".trim(), "", '"\u00A0\u00A0".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-35.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-35.js
index 667c167416..4324a99b18 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-35.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-35.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-35
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (ab\u0009c)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("ab\u0009c".trim() === "ab\u0009c") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("ab\u0009c".trim(), "ab\u0009c", '"ab\u0009c".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-36.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-36.js
index 34723ac462..6aab569a09 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-36.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-36.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-36
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (ab\u000Bc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("ab\u000Bc".trim() === "ab\u000Bc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("ab\u000Bc".trim(), "ab\u000Bc", '"ab\u000Bc".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-37.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-37.js
index cb6c7f8e22..9c96555557 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-37.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-37.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-37
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (ab\u000Cc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("ab\u000Cc".trim() === "ab\u000Cc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("ab\u000Cc".trim(), "ab\u000Cc", '"ab\u000Cc".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-38.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-38.js
index 9f294c4214..6d8254f070 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-38.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-38.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-38
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (ab\u0020c)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("ab\u0020c".trim() === "ab\u0020c") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("ab\u0020c".trim(), "ab\u0020c", '"ab\u0020c".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-4.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-4.js
index a9a1fdcb66..5fee51f1dc 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-4.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-4.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-4
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u000Babc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u000Babc".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u000Babc".trim(), "abc", '"\u000Babc".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-40.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-40.js
index 59941b09d5..ca352deebc 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-40.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-40.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-40
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (ab\u00A0c)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("ab\u00A0c".trim() === "ab\u00A0c") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("ab\u00A0c".trim(), "ab\u00A0c", '"ab\u00A0c".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-41.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-41.js
index 53f4ac0a53..acf7f33cfe 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-41.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-41.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-41
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (ab\u200Bc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("ab\u200Bc".trim() === "ab\u200Bc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("ab\u200Bc".trim(), "ab\u200Bc", '"ab\u200Bc".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-42.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-42.js
index 31ac2106ab..fe54dd19ca 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-42.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-42.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-42
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (ab\uFEFFc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("ab\uFEFFc".trim() === "ab\uFEFFc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("ab\uFEFFc".trim(), "ab\uFEFFc", '"ab\uFEFFc".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-43.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-43.js
index a1253b33ef..d475a888c5 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-43.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-43.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-43
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u000Aabc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u000Aabc".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u000Aabc".trim(), "abc", '"\u000Aabc".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-44.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-44.js
index 23b9c7cf1f..3a368677a2 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-44.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-44.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-44
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u000Dabc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u000Dabc".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u000Dabc".trim(), "abc", '"\u000Dabc".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-45.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-45.js
index f92d9df2a9..2a1811a92c 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-45.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-45.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-45
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u2028abc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u2028abc".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u2028abc".trim(), "abc", '"\u2028abc".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-46.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-46.js
index f40ad4c928..20653a56d0 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-46.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-46.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-46
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u2029abc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u2029abc".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u2029abc".trim(), "abc", '"\u2029abc".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-47.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-47.js
index 6dcf7da9dc..3ac00096a8 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-47.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-47.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-47
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (abc\u000A)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("abc\u000A".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("abc\u000A".trim(), "abc", '"abc\u000A".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-48.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-48.js
index f16dfcf8f5..5e3bb87857 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-48.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-48.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-48
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (abc\u000D)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("abc\u000D".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("abc\u000D".trim(), "abc", '"abc\u000D".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-49.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-49.js
index 288582b180..aff1fa5af0 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-49.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-49.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-49
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (abc\u2028)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("abc\u2028".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("abc\u2028".trim(), "abc", '"abc\u2028".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-5.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-5.js
index 9af3935a39..b5473c26db 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-5.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-5.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-5
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u000Cabc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u000Cabc".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u000Cabc".trim(), "abc", '"\u000Cabc".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-50.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-50.js
index 49f5dcdea5..74280cb918 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-50.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-50.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-50
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (abc\u2029)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("abc\u2029".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("abc\u2029".trim(), "abc", '"abc\u2029".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-51.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-51.js
index daf957ec81..308a62ad23 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-51.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-51.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-51
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u000Aabc\u000A)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u000Aabc\u000A".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u000Aabc\u000A".trim(), "abc", '"\u000Aabc\u000A".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-52.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-52.js
index 4b81cf24c1..846ff7e9d6 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-52.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-52.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-52
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u000Dabc\u000D)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u000Dabc\u000D".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u000Dabc\u000D".trim(), "abc", '"\u000Dabc\u000D".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-53.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-53.js
index ff0a0b258e..97e8949f87 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-53.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-53.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-53
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u2028abc\u2028)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u2028abc\u2028".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u2028abc\u2028".trim(), "abc", '"\u2028abc\u2028".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-54.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-54.js
index aa51015f48..3fab5ec6eb 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-54.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-54.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-54
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u2029abc\u2029)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u2029abc\u2029".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u2029abc\u2029".trim(), "abc", '"\u2029abc\u2029".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-55.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-55.js
index 6997e3bbbc..ccbe68cbe7 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-55.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-55.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-55
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u000A\u000A)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u000A\u000A".trim() === "") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u000A\u000A".trim(), "", '"\u000A\u000A".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-56.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-56.js
index b0371c1f52..2f648d6928 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-56.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-56.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-56
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u000D\u000D)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u000D\u000D".trim() === "") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u000D\u000D".trim(), "", '"\u000D\u000D".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-57.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-57.js
index 10fe688aca..e13d6a0c08 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-57.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-57.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-57
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u2028\u2028)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u2028\u2028".trim() === "") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u2028\u2028".trim(), "", '"\u2028\u2028".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-58.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-58.js
index f34a8b6109..b06974f583 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-58.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-58.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-58
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u2029\u2029)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u2029\u2029".trim() === "") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u2029\u2029".trim(), "", '"\u2029\u2029".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-59.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-59.js
index b041e0ab38..13a98eb6c5 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-59.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-59.js
@@ -6,14 +6,9 @@ es5id: 15.5.4.20-4-59
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u2029abc as a multiline string)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
   var s = "\u2029\
            abc";
-  if (s.trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+
+assert.sameValue(s.trim(), "abc", 's.trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-6.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-6.js
index 410c064552..e37c01bbaf 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-6.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-6.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-6
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u0020abc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u0020abc".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u0020abc".trim(), "abc", '"\u0020abc".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-60.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-60.js
index 95af050af0..6cd066500d 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-60.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-60.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-60
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (string with just blanks)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("    ".trim() === "") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("    ".trim(), "", '"    ".trim()');
diff --git a/test/built-ins/String/prototype/trim/15.5.4.20-4-8.js b/test/built-ins/String/prototype/trim/15.5.4.20-4-8.js
index 6b156d9952..0304afed30 100644
--- a/test/built-ins/String/prototype/trim/15.5.4.20-4-8.js
+++ b/test/built-ins/String/prototype/trim/15.5.4.20-4-8.js
@@ -6,12 +6,6 @@ es5id: 15.5.4.20-4-8
 description: >
     String.prototype.trim handles whitepace and lineterminators
     (\u00A0abc)
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
-  if ("\u00A0abc".trim() === "abc") {
-    return true;
-  }
- }
-runTestCase(testcase);
+assert.sameValue("\u00A0abc".trim(), "abc", '"\u00A0abc".trim()');