Prefer explicit error checking where possible

The `negative` frontmatter tag expresses an expectation for the behavior
of the test file as a whole. The `assert.throws` helper function offers
more fine-grained control over expectations because it may be applied to
specific statements and expressions. This makes it preferable in cases
where it may be used (i.e. when the test body does not describe a syntax
error or early error).

Re-implement assertions for errors to use the `assert.throws` helper
function wherever possible.

test/built-ins/Array/prototype/splice/S15.4.4.12_A6.1_T2.js

@@ -5,7 +5,6 @@
 info: Array.prototype.splice sets `length` on `this`
 es5id: 15.4.4.12_A6.1_T2
 description: Array.prototype.splice throws if `length` is read-only
-negative: TypeError
 ---*/
 
 var a = [0, 1, 2];
@@ -14,4 +13,6 @@ Object.defineProperty(a, 'length', {
     writable: false
 });
 
-a.splice(1, 2, 4);
+assert.throws(TypeError, function() {
+  a.splice(1, 2, 4);
+});

test/built-ins/Function/15.3.5-2gs.js

@@ -9,10 +9,11 @@ es5id: 15.3.5-2gs
 description: >
     StrictMode - error is thrown when reading the 'caller' property of
     a function object
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
 function _15_3_5_1_gs() {}
-_15_3_5_1_gs.caller;
-throw NotEarlyError;
+
+assert.throws(TypeError, function() {
+  _15_3_5_1_gs.caller;
+});

test/built-ins/Function/15.3.5.4_2-10gs.js

@@ -10,13 +10,14 @@ description: >
     Strict mode - checking access to strict function caller from
     non-strict function (New'ed Function constructor includes strict
     directive prologue)
-negative: TypeError
 flags: [noStrict]
 ---*/
 
 var f = new Function("\"use strict\";\nreturn gNonStrict();");
-f();
 
+assert.throws(TypeError, function() {
+    f();
+});
 
 function gNonStrict() {
     return gNonStrict.caller || gNonStrict.caller.throwTypeError;

test/built-ins/Function/15.3.5.4_2-11gs.js

@@ -9,11 +9,12 @@ es5id: 15.3.5.4_2-11gs
 description: >
     Strict mode - checking access to strict function caller from
     strict function (eval used within strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
-eval("gNonStrict();");
+assert.throws(TypeError, function() {
+    eval("gNonStrict();");
+});
 
 
 function gNonStrict() {

test/built-ins/Function/15.3.5.4_2-13gs.js

@@ -9,13 +9,14 @@ es5id: 15.3.5.4_2-13gs
 description: >
     Strict mode - checking access to non-strict function caller from
     strict function (indirect eval used within strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
 var my_eval = eval;
-my_eval("gNonStrict();");
 
+assert.throws(TypeError, function() {
+    my_eval("gNonStrict();");
+});
 
 function gNonStrict() {
     return gNonStrict.caller;

test/built-ins/Function/15.3.5.4_2-15gs.js

@@ -10,15 +10,16 @@ description: >
     Strict mode - checking access to strict function caller from
     strict function (New'ed object from FunctionDeclaration defined
     within strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
 function f() {
     return gNonStrict();
 }
-new f();
 
+assert.throws(TypeError, function() {
+    new f();
+});
 
 function gNonStrict() {
     return gNonStrict.caller;

test/built-ins/Function/15.3.5.4_2-16gs.js

@@ -10,7 +10,6 @@ description: >
     Strict mode - checking access to strict function caller from
     non-strict function (New'ed object from FunctionDeclaration
     includes strict directive prologue)
-negative: TypeError
 flags: [noStrict]
 ---*/
 
@@ -18,8 +17,10 @@ function f() {
     "use strict";
     return gNonStrict();
 }
-new f();
 
+assert.throws(TypeError, function() {
+    new f();
+});
 
 function gNonStrict() {
     return gNonStrict.caller || gNonStrict.caller.throwTypeError;

test/built-ins/Function/15.3.5.4_2-17gs.js

@@ -10,15 +10,16 @@ description: >
     Strict mode - checking access to strict function caller from
     strict function (New'ed object from FunctionExpression defined
     within strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
 var f = function () {
     return gNonStrict();
 }
-new f();
 
+assert.throws(TypeError, function() {
+    new f();
+});
 
 function gNonStrict() {
     return gNonStrict.caller;

test/built-ins/Function/15.3.5.4_2-18gs.js

@@ -10,7 +10,6 @@ description: >
     Strict mode - checking access to strict function caller from
     non-strict function (New'ed object from FunctionExpression
     includes strict directive prologue)
-negative: TypeError
 flags: [noStrict]
 ---*/
 
@@ -18,8 +17,10 @@ var f = function () {
     "use strict";
     return gNonStrict();
 }
-new f();
 
+assert.throws(TypeError, function() {
+    new f();
+});
 
 function gNonStrict() {
     return gNonStrict.caller || gNonStrict.caller.throwTypeError;

test/built-ins/Function/15.3.5.4_2-19gs.js

@@ -10,15 +10,15 @@ description: >
     Strict mode - checking access to strict function caller from
     strict function (New'ed object from Anonymous FunctionExpression
     defined within strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
-var obj = new (function () {
-    return gNonStrict();
+assert.throws(TypeError, function() {
+    var obj = new (function () {
+        return gNonStrict();
+    });
 });
 
-
 function gNonStrict() {
     return gNonStrict.caller;
 }

test/built-ins/Function/15.3.5.4_2-1gs.js

@@ -9,15 +9,16 @@ es5id: 15.3.5.4_2-1gs
 description: >
     Strict mode - checking access to strict function caller from
     strict function (FunctionDeclaration defined within strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
 function f() {
     return gNonStrict();
 }
-f();
 
+assert.throws(TypeError, function() {
+    f();
+});
 
 function gNonStrict() {
     return gNonStrict.caller;

test/built-ins/Function/15.3.5.4_2-20gs.js

@@ -10,13 +10,14 @@ description: >
     Strict mode - checking access to strict function caller from
     non-strict function (New'ed object from Anonymous
     FunctionExpression includes strict directive prologue)
-negative: TypeError
 flags: [noStrict]
 ---*/
 
-var obj = new (function () {
-    "use strict";
-    return gNonStrict();
+assert.throws(TypeError, function() {
+    var obj = new (function () {
+        "use strict";
+        return gNonStrict();
+    });
 });
 
 

test/built-ins/Function/15.3.5.4_2-21gs.js

@@ -10,7 +10,6 @@ description: >
     Strict mode - checking access to strict function caller from
     strict function (FunctionDeclaration defined within a
     FunctionDeclaration inside strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
@@ -20,8 +19,10 @@ function f1() {
     }
     return f();
 }
-f1();
 
+assert.throws(TypeError, function() {
+    f1();
+});
 
 function gNonStrict() {
     return gNonStrict.caller;

test/built-ins/Function/15.3.5.4_2-22gs.js

@@ -10,7 +10,6 @@ description: >
     Strict mode - checking access to strict function caller from
     strict function (FunctionExpression defined within a
     FunctionDeclaration inside strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
@@ -20,8 +19,10 @@ function f1() {
     }
     return f();
 }
-f1();
 
+assert.throws(TypeError, function() {
+    f1();
+});
 
 function gNonStrict() {
     return gNonStrict.caller;

test/built-ins/Function/15.3.5.4_2-23gs.js

@@ -10,7 +10,6 @@ description: >
     Strict mode - checking access to strict function caller from
     strict function (Anonymous FunctionExpression defined within a
     FunctionDeclaration inside strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
@@ -19,8 +18,10 @@ function f1() {
         return gNonStrict();
     })();
 }
-f1();
 
+assert.throws(TypeError, function() {
+    f1();
+});
 
 function gNonStrict() {
     return gNonStrict.caller;

test/built-ins/Function/15.3.5.4_2-24gs.js

@@ -10,7 +10,6 @@ description: >
     Strict mode - checking access to strict function caller from
     strict function (FunctionDeclaration defined within a
     FunctionExpression inside strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
@@ -20,7 +19,10 @@ var f1 = function () {
     }
     return f();
 }
-f1();
+
+assert.throws(TypeError, function() {
+    f1();
+});
 
 
 function gNonStrict() {

test/built-ins/Function/15.3.5.4_2-25gs.js

@@ -10,7 +10,6 @@ description: >
     Strict mode - checking access to strict function caller from
     strict function (FunctionExpression defined within a
     FunctionExpression inside strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
@@ -20,8 +19,10 @@ var f1 = function () {
     }
     return f();
 }
-f1();
 
+assert.throws(TypeError, function() {
+    f1();
+});
 
 function gNonStrict() {
     return gNonStrict.caller;

test/built-ins/Function/15.3.5.4_2-26gs.js

@@ -10,7 +10,6 @@ description: >
     Strict mode - checking access to strict function caller from
     strict function (Anonymous FunctionExpression defined within a
     FunctionExpression inside strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
@@ -19,8 +18,10 @@ var f1 = function () {
         return gNonStrict();
     })();
 }
-f1();
 
+assert.throws(TypeError, function() {
+    f1();
+});
 
 function gNonStrict() {
     return gNonStrict.caller;

test/built-ins/Function/15.3.5.4_2-27gs.js

@@ -10,17 +10,17 @@ description: >
     Strict mode - checking access to strict function caller from
     strict function (FunctionDeclaration defined within an Anonymous
     FunctionExpression inside strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
-(function () {
-    function f() {
-        return gNonStrict();
-    }
-    return f();
-})();
-
+assert.throws(TypeError, function() {
+    (function () {
+        function f() {
+            return gNonStrict();
+        }
+        return f();
+    })();
+});
 
 function gNonStrict() {
     return gNonStrict.caller;

test/built-ins/Function/15.3.5.4_2-28gs.js

@@ -10,16 +10,17 @@ description: >
     Strict mode - checking access to strict function caller from
     strict function (FunctionExpression defined within an Anonymous
     FunctionExpression inside strict mode)
-negative: TypeError
 flags: [onlyStrict]
 ---*/
 
-(function () {
-    var f = function () {
-        return gNonStrict();
-    }
-    return f();
-})();
+assert.throws(TypeError, function() {
+    (function () {
+        var f = function () {
+            return gNonStrict();
+        }
+        return f();
+    })();
+});
 
 
 function gNonStrict() {