Increase branch coverage: Array.prototype functions

Added new test cases to improve branch coverage in Array.prototype routines.

The following script is made for testing branch coverage with all the test suites (--jerry-test-suite --test262 --unittests --jerry-tests), or with only one .js file.

https://github.com/matedabis/jerryscript/blob/gcov_coverage_tester/tests/gcov-tests/gcovtester.py

While measuring the branch coverage we dont count JERRY_ASSERT s. The results are measured by running all the test scripts, with the modifications in the PRs.

Branch coverage including pando-project#2682 and pando-project#2674:
	-before: 399 / 476
	-after:  472 / 476

There are 28 functions in ecma-builtin-array-prototype.c, we hit 14 from them.
The other 14 functions are either already covered, or we could not improve the coverage of it.

More information about the coverage improvement and the branches not reached:
https://gist.github.com/matedabis/d7b9fc0690aa2f4be6aa160fdf482e0e

While improving the coverage we found an unnecessary condition check, which can not be false in any cases.

Co-authored-by: Csaba Repasi repasics@inf.u-szeged.hu
JerryScript-DCO-1.0-Signed-off-by: Csaba Repasi repasics@inf.u-szeged.hu
JerryScript-DCO-1.0-Signed-off-by: Mate Dabis mdabis@inf.u-szeged.hu

Author: matedabis

jerry-core/ecma/builtin-objects/ecma-builtin-array-prototype.c

@@ -579,7 +579,7 @@ ecma_builtin_array_prototype_object_reverse (ecma_value_t this_arg, /**< this ar
       ECMA_FINALIZE (put_value);
     }
     /* 6.j */
-    else if (lower_exist && !upper_exist)
+    else if (lower_exist)
     {
       ECMA_TRY_CATCH (del_value, ecma_op_object_delete (obj_p, lower_str_p, true), ret_value);
       ECMA_TRY_CATCH (put_value, ecma_op_object_put (obj_p, upper_str_p, lower_value, true), ret_value);
@@ -1224,8 +1224,9 @@ ecma_builtin_array_prototype_object_splice (const ecma_value_t args[], /**< argu
       }
     }
     /* 13. */
-    else if (item_count > delete_count)
+    else
     {
+      JERRY_ASSERT (item_count > delete_count);
       /* 13.b */
       for (k = len - delete_count; k > start  && ecma_is_value_empty (ret_value); k--)
       {

tests/jerry/array-prototype-concat.js

@@ -74,3 +74,17 @@ try {
   assert(e.message === "foo");
   assert(e instanceof ReferenceError);
 }
+
+/* ES v5.1 15.4.4.4.5.
+   Checking behavior when unable to get element from a given array */
+arr1 = [];
+arr2 = [];
+arr3 = [];
+Object.defineProperty(arr2, '0', { 'get' : function () {throw new ReferenceError ("foo"); } });
+
+try {
+  arr1.concat(arr2, arr3);
+  assert(false);
+} catch (e) {
+  assert(e instanceof ReferenceError);
+}

tests/jerry/array-prototype-join.js

@@ -74,3 +74,16 @@ obj_2[3] = 4;
 obj_2.join = Array.prototype.join;
 
 assert (obj_2.join() === "1,2,3");
+
+/* ES v5.1 15.4.4.5.7.
+   Checking behavior when an element throws error */
+try {
+  var f = function () { throw new TypeError("ooo");};
+  var arr = [0, 1, 2, 3];
+  Object.defineProperty(arr, '0', { 'get' : f });
+  Array.prototype.join.call(arr);
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+  assert(e.message == "ooo");
+}

tests/jerry/array-prototype-pop.js

@@ -72,3 +72,27 @@ try {
   assert(e.message === "foo");
   assert(e instanceof ReferenceError);
 }
+
+/* ES v5.1 15.4.4.6.5.c
+   Checking behavior when unable to delete property */
+var obj = {pop : Array.prototype.pop, length : 2};
+Object.defineProperty(obj, '1', function () {});
+
+try {
+  obj.pop();
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}
+
+/* ES v5.1 15.4.4.6.5.d
+   Checking behavior when array is not modifiable */
+var obj = {pop : Array.prototype.pop, length : 2};
+Object.freeze(obj);
+
+try {
+  obj.pop();
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}

tests/jerry/array-prototype-push.js

@@ -74,3 +74,15 @@ try {
 }
 assert(o.length === 1);
 assert(o[0] === "z");
+
+/* ES v5.1 15.4.4.7.5.
+   Checking behavior when array is non-extensible while pushing */
+var arr = [];
+Object.freeze(arr);
+
+try {
+  arr.push(1, 2);
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}

tests/jerry/array-prototype-reverse.js

@@ -43,3 +43,77 @@ try {
   assert(e.message === "foo");
   assert(e instanceof ReferenceError);
 }
+
+/* ES v5.1 15.4.4.8.6.e.
+   Checking behavior when unable to get the last element */
+var obj = { reverse : Array.prototype.reverse, length : 4 };
+Object.defineProperty(obj, '3', { 'get' : function () {throw new ReferenceError ("foo"); } });
+
+try {
+  obj.reverse();
+  assert(false);
+} catch (e) {
+  assert(e.message === "foo");
+  assert(e instanceof ReferenceError);
+}
+
+/* ES v5.1 15.4.4.8.6.h.i.
+   Checking behavior when first 3 elements are not writable */
+try {
+  var arr = [0, 1, 2, 3, 4, 5, 6,,,,,,,,,0, 1, 2, 3, 4, 5, 6];
+  Object.defineProperty(arr, '0', { writable : false });
+  Object.defineProperty(arr, '1', { writable : false });
+  Object.defineProperty(arr, '2', { writable : false });
+  Array.prototype.reverse.call(arr);
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}
+
+/* ES v5.1 15.4.4.8.6.h.ii.
+   Checking behavior when last 3 elements are not writable */
+try {
+  var arr = [0, 1, 2, 3, 4, 5, 6,,,,,,,,,0, 1, 2, 3, 4, 5, 6];
+  Object.defineProperty(arr, '20', { writable : false });
+  Object.defineProperty(arr, '21', { writable : false });
+  Object.defineProperty(arr, '22', { writable : false });
+  Array.prototype.reverse.call(arr);
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}
+
+/* ES v5.1 15.4.4.8.6.i.i.
+   Checking behavior when first elements do not exist and the array is freezed */
+try {
+  var arr = [,,,,,,,,,,,,,,,,0, 1, 2, 3, 4, 5, 6];
+  arr = Object.freeze(arr);
+  Array.prototype.reverse.call(arr);
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}
+
+/* ES v5.1 15.4.4.8.6.i.ii.
+   Checking behavior when unable to get the first 2 elements */
+var obj = { reverse : Array.prototype.reverse, length : 4 };
+Object.defineProperty(obj, '2', { value : 0 });
+Object.defineProperty(obj, '3', { value : 0 });
+try {
+  obj.reverse();
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}
+
+/* ES v5.1 15.4.4.8.6.j.i.
+   Checking behavior when unable to get the last 2 elements */
+var obj = { reverse : Array.prototype.reverse, length : 4 };
+Object.defineProperty(obj, '0', { value : 0 });
+Object.defineProperty(obj, '1', { value : 0 });
+try {
+  obj.reverse();
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}

tests/jerry/array-prototype-shift.js

@@ -77,3 +77,61 @@ try {
   assert(e.message === "foo");
   assert(e instanceof ReferenceError);
 }
+
+/* ES v5.1 15.4.4.9.7.c.
+   Checking behavior when the array is freezed */
+try {
+  f = function () { throw new ReferenceError("getter"); };
+  arr =  { length : 9 };
+  Object.defineProperty(arr, '8', { 'get' : f });
+  Array.prototype.shift.call(arr);
+  assert(false);
+} catch (e) {
+  assert(e instanceof ReferenceError);
+  assert(e.message == "getter");
+}
+
+/* ES v5.1 15.4.4.9.7.d.ii.
+   Checking behavior when the array is freezed */
+try {
+  arr =  { length : 9 };
+  Object.defineProperty(arr, '8', { value : 8 });
+  Object.defineProperty(arr, '7', { value : 7 });
+  Array.prototype.shift.call(arr);
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}
+
+/* ES v5.1 15.4.4.9.7.e.i.
+   Checking behavior when the first element is null */
+try {
+  arr = { length : 9 };
+  Object.defineProperty(arr, '0', { value : null });
+  Array.prototype.shift.call(arr);
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}
+
+/* ES v5.1 15.4.4.9.8.
+   Checking behavior when last element is not writable */
+try {
+  arr = { length : 9 };
+  Object.defineProperty(arr, '8', { writable : false });
+  Array.prototype.shift.call(arr);
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}
+
+/* ES v5.1 15.4.4.9.9.
+   Checking behavior when the array is freezed */
+try {
+  arr = { length : 9 };
+  Object.freeze(arr);
+  Array.prototype.shift.call(arr);
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}

tests/jerry/array-prototype-slice.js

@@ -110,3 +110,44 @@ try {
   assert (e.message === "foo");
   assert (e instanceof ReferenceError);
 }
+
+/* ES v5.1 15.4.4.10.5.
+   Checking behavior when start value throws exception */
+var arg1 = { };
+Object.defineProperty(arg1, 'valueOf', { 'get' : function () { throw new ReferenceError ("foo"); } });
+var obj = { slice : Array.prototype.slice };
+
+try {
+  obj.slice(arg1);
+  assert(false);
+} catch (e) {
+  assert(e.message === 'foo');
+  assert(e instanceof ReferenceError);
+}
+
+/* ES v5.1 15.4.4.10.7.
+   Checking behavior when end value throws exception */
+var arg2 = { };
+Object.defineProperty(arg2, 'valueOf', { 'get' : function () { throw new ReferenceError ("foo"); } });
+var obj = { slice : Array.prototype.slice };
+
+try {
+  obj.slice(0, arg2);
+  assert(false);
+} catch (e) {
+  assert(e.message === 'foo');
+  assert(e instanceof ReferenceError);
+}
+
+/* ES v5.1 15.4.4.10.10.
+   Checking behavior when unable to get element */
+var obj = { length : 3, slice : Array.prototype.slice };
+Object.defineProperty(obj, '1', { 'get' : function () { throw new ReferenceError ("foo"); } });
+
+try {
+  obj.slice(0, 3);
+  assert (false);
+} catch (e) {
+  assert (e.message === "foo");
+  assert (e instanceof ReferenceError);
+}

tests/jerry/array-prototype-sort.js

@@ -92,3 +92,95 @@ try {
   assert(e.message === "foo");
   assert(e instanceof ReferenceError);
 }
+
+// Checking behavior when unable to get elements
+var obj = { sort : Array.prototype.sort, length : 2};
+Object.defineProperty(obj, '0', { 'get' : function () { throw new ReferenceError ("foo"); } });
+Object.defineProperty(obj, '1', { 'get' : function () { throw new ReferenceError ("bar"); } });
+
+try {
+  obj.sort();
+  assert(false);
+} catch (e) {
+  assert(e.message === "foo");
+  assert(e instanceof ReferenceError);
+}
+
+// Checking behavior when array is non-extensible while sorting
+var arr = [1, 0];
+
+try {
+  arr.sort(function () { Object.freeze(arr) });
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}
+
+// Checking behavior when unable to delete property
+var obj = {sort : Array.prototype.sort, '0' : 2, '1' : 1, length : 4};
+Object.defineProperty(obj, '3', function () {});
+
+try {
+  obj.sort();
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}
+
+// Checking behavior when unable to get the last element
+var arr = [1, 2, ];
+Object.defineProperty(arr, '2', { 'get' : function () { throw new ReferenceError ("foo"); } });
+
+try {
+  arr.sort();
+  assert(false);
+} catch (e) {
+  assert(e.message === 'foo');
+  assert(e instanceof ReferenceError);
+}
+
+// Checking behavior when lhs_value throws exception at comparefn
+f = function () { throw new ReferenceError('foo'); };
+obj = { 'toString' : f };
+arr = [obj, 1];
+
+try {
+  arr.sort();
+  assert(false);
+} catch (e) {
+  assert(e.message === 'foo');
+  assert(e instanceof ReferenceError);
+}
+
+// Checking behavior when rhs_value throws exception at comparefn
+f = function () { throw new ReferenceError('foo'); };
+obj = { 'toString' : f };
+arr = [1, obj];
+
+try {
+  arr.sort();
+  assert(false);
+} catch (e) {
+  assert(e.message === 'foo');
+  assert(e instanceof ReferenceError);
+}
+
+// Sorting when array elements are the same string
+arr = ['foo', 'foo'];
+arr.sort();
+
+assert(arr[0] === 'foo');
+assert(arr[1] === 'foo');
+
+// Checking behavior when comparefn's call value cannot be converted to number
+obj = { };
+Object.defineProperty(obj, 'toString', function () { });
+f = function () { return obj };
+arr = [1, 2];
+
+try {
+  arr.sort(f);
+  assert(false);
+} catch (e) {
+  assert(e instanceof TypeError);
+}