diff --git a/CMakeLists.txt b/CMakeLists.txt
index 609c2b4f94..6d2a3eb69b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -421,7 +421,7 @@ project (Jerry CXX C ASM)
 
    foreach(SOURCE_UNIT_TEST_MAIN ${SOURCE_UNIT_TEST_MAIN_MODULES})
     get_filename_component(TARGET_NAME ${SOURCE_UNIT_TEST_MAIN} NAME_WE)
-    set(TARGET_NAME unit_${TARGET_NAME})
+    set(TARGET_NAME unit-${TARGET_NAME})
 
     set(CORE_TARGET_NAME unittests.jerry-core)
     set(FDLIBM_TARGET_NAME unittests.jerry-fdlibm${SUFFIX_THIRD_PARTY_LIB})
diff --git a/Makefile b/Makefile
index e303e0c224..e1909f42c9 100644
--- a/Makefile
+++ b/Makefile
@@ -207,7 +207,7 @@ unittests: $(BUILD_DIR)/native
           (echo "cppcheck run failed. See $(OUT_DIR)/$@/cppcheck.log for details."; exit 1;)
 	@ $(MAKE) -C $(BUILD_DIR)/native VERBOSE=1 $@ &>$(OUT_DIR)/$@/make.log || \
           (echo "Build failed. See $(OUT_DIR)/$@/make.log for details."; exit 1;)
-	@ cp $(BUILD_DIR)/native/unit_test_* $(OUT_DIR)/$@
+	@ cp $(BUILD_DIR)/native/unit-test-* $(OUT_DIR)/$@
 
 $(BUILD_ALL)_native: $(BUILD_DIRS_NATIVE)
 	@ mkdir -p $(OUT_DIR)/$@
diff --git a/tests/unit/common.h b/tests/unit/common.h
deleted file mode 100644
index c3800e0c7b..0000000000
--- a/tests/unit/common.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/* Copyright 2014-2015 Samsung Electronics Co., Ltd.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef COMMON_H
-#define COMMON_H
-
-#define NAME_TO_ID(op) (__op__idx_##op)
-
-#define __OPCODE_SIZE(name, arg1, arg2, arg3) \
-  (uint8_t) (sizeof (__op_##name) + 1),
-
-static uint8_t opcode_sizes[] =
-{
-  OP_LIST (OPCODE_SIZE)
-  0
-};
-
-static bool opcodes_equal (const opcode_t *, opcode_t *, uint16_t) __attr_unused___;
-
-static bool
-opcodes_equal (const opcode_t *opcodes1, opcode_t *opcodes2, uint16_t size)
-{
-  uint16_t i;
-  for (i = 0; i < size; i++)
-  {
-    uint8_t opcode_num1 = opcodes1[i].op_idx, opcode_num2 = opcodes2[i].op_idx;
-    uint8_t j;
-
-    if (opcode_num1 != opcode_num2)
-    {
-      return false;
-    }
-
-    if (opcode_num1 == NAME_TO_ID (nop) || opcode_num1 == NAME_TO_ID (ret))
-    {
-      return true;
-    }
-
-    for (j = 1; j < opcode_sizes[opcode_num1]; j++)
-    {
-      if (((uint8_t*)&opcodes1[i])[j] != ((uint8_t*)&opcodes2[i])[j])
-      {
-        return false;
-      }
-    }
-  }
-
-  return true;
-}
-
-#endif // COMMON_H
diff --git a/tests/unit/test_api.cpp b/tests/unit/test-api.cpp
similarity index 79%
rename from tests/unit/test_api.cpp
rename to tests/unit/test-api.cpp
index ada2e6de13..ddd8977d00 100644
--- a/tests/unit/test_api.cpp
+++ b/tests/unit/test-api.cpp
@@ -13,14 +13,11 @@
  * limitations under the License.
  */
 
-#include <assert.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-
 #include "jerry.h"
 #include "jerry-api.h"
 
+#include "test-common.h"
+
 const char *test_source = (
                            "this.t = 1; "
                            "function f () { "
@@ -111,17 +108,17 @@ handler (const jerry_api_object_t *function_obj_p,
 
   printf ("ok %p %p %p %d %p\n", function_obj_p, this_p, args_p, args_cnt, ret_val_p);
 
-  assert (args_cnt == 2);
+  JERRY_ASSERT (args_cnt == 2);
 
-  assert (args_p[0].type == JERRY_API_DATA_TYPE_STRING);
+  JERRY_ASSERT (args_p[0].type == JERRY_API_DATA_TYPE_STRING);
   sz = jerry_api_string_to_char_buffer (args_p[0].v_string, NULL, 0);
-  assert (sz == -2);
+  JERRY_ASSERT (sz == -2);
   sz = jerry_api_string_to_char_buffer (args_p[0].v_string, buffer, -sz);
-  assert (sz == 2);
-  assert (!strcmp (buffer, "1"));
+  JERRY_ASSERT (sz == 2);
+  JERRY_ASSERT (!strcmp (buffer, "1"));
 
-  assert (args_p[1].type == JERRY_API_DATA_TYPE_BOOLEAN);
-  assert (args_p[1].v_bool == true);
+  JERRY_ASSERT (args_p[1].type == JERRY_API_DATA_TYPE_BOOLEAN);
+  JERRY_ASSERT (args_p[1].v_bool == true);
 
   test_api_init_api_value_string (ret_val_p, "string from handler");
 
@@ -149,7 +146,7 @@ handler_throw_test (const jerry_api_object_t *function_obj_p,
 static void
 handler_construct_freecb (uintptr_t native_p)
 {
-  assert (native_p == (uintptr_t) 0x0012345678abcdefull);
+  JERRY_ASSERT (native_p == (uintptr_t) 0x0012345678abcdefull);
   printf ("ok object free callback\n");
 
   test_api_is_free_callback_was_called = true;
@@ -164,12 +161,12 @@ handler_construct (const jerry_api_object_t *function_obj_p,
 {
   printf ("ok construct %p %p %p %d %p\n", function_obj_p, this_p, args_p, args_cnt, ret_val_p);
 
-  assert (this_p != NULL);
-  assert (this_p->type == JERRY_API_DATA_TYPE_OBJECT);
+  JERRY_ASSERT (this_p != NULL);
+  JERRY_ASSERT (this_p->type == JERRY_API_DATA_TYPE_OBJECT);
 
-  assert (args_cnt == 1);
-  assert (args_p[0].type == JERRY_API_DATA_TYPE_BOOLEAN);
-  assert (args_p[0].v_bool == true);
+  JERRY_ASSERT (args_cnt == 1);
+  JERRY_ASSERT (args_p[0].type == JERRY_API_DATA_TYPE_BOOLEAN);
+  JERRY_ASSERT (args_p[0].v_bool == true);
 
   jerry_api_set_object_field_value (this_p->v_object, "value_field", &args_p[0]);
 
@@ -234,44 +231,44 @@ main (void)
   char buffer[32];
 
   is_ok = jerry_parse (test_source, strlen (test_source));
-  assert (is_ok);
+  JERRY_ASSERT (is_ok);
 
   is_ok = (jerry_run () == JERRY_COMPLETION_CODE_OK);
-  assert (is_ok);
+  JERRY_ASSERT (is_ok);
 
   global_obj_p = jerry_api_get_global ();
 
   // Get global.t
   is_ok = jerry_api_get_object_field_value (global_obj_p, "t", &val_t);
-  assert (is_ok
-          && val_t.type == JERRY_API_DATA_TYPE_FLOAT64
-          && val_t.v_float64 == 1.0);
+  JERRY_ASSERT (is_ok
+                && val_t.type == JERRY_API_DATA_TYPE_FLOAT64
+                && val_t.v_float64 == 1.0);
   jerry_api_release_value (&val_t);
 
   // Get global.foo
   is_ok = jerry_api_get_object_field_value (global_obj_p, "foo", &val_foo);
-  assert (is_ok
-          && val_foo.type == JERRY_API_DATA_TYPE_OBJECT);
+  JERRY_ASSERT (is_ok
+                && val_foo.type == JERRY_API_DATA_TYPE_OBJECT);
 
   // Call foo (4, 2)
   test_api_init_api_value_float64 (&args[0], 4);
   test_api_init_api_value_float64 (&args[1], 2);
   is_ok = jerry_api_call_function (val_foo.v_object, NULL, &res, args, 2);
-  assert (is_ok
-          && res.type == JERRY_API_DATA_TYPE_FLOAT64
-          && res.v_float64 == 1.0);
+  JERRY_ASSERT (is_ok
+                && res.type == JERRY_API_DATA_TYPE_FLOAT64
+                && res.v_float64 == 1.0);
   jerry_api_release_value (&res);
 
   // Get global.bar
   is_ok = jerry_api_get_object_field_value (global_obj_p, "bar", &val_bar);
-  assert (is_ok
-          && val_bar.type == JERRY_API_DATA_TYPE_OBJECT);
+  JERRY_ASSERT (is_ok
+                && val_bar.type == JERRY_API_DATA_TYPE_OBJECT);
 
   // Call bar (4, 2)
   is_ok = jerry_api_call_function (val_bar.v_object, NULL, &res, args, 2);
-  assert (is_ok
-          && res.type == JERRY_API_DATA_TYPE_FLOAT64
-          && res.v_float64 == 5.0);
+  JERRY_ASSERT (is_ok
+                && res.type == JERRY_API_DATA_TYPE_FLOAT64
+                && res.v_float64 == 5.0);
   jerry_api_release_value (&res);
   jerry_api_release_value (&val_bar);
 
@@ -280,65 +277,65 @@ main (void)
   is_ok = jerry_api_set_object_field_value (global_obj_p,
                                             "t",
                                             &args[0]);
-  assert (is_ok);
+  JERRY_ASSERT (is_ok);
   jerry_api_release_value (&args[0]);
 
   // Call foo (4, 2)
   is_ok = jerry_api_call_function (val_foo.v_object, NULL, &res, args, 2);
-  assert (is_ok
-          && res.type == JERRY_API_DATA_TYPE_STRING);
+  JERRY_ASSERT (is_ok
+                && res.type == JERRY_API_DATA_TYPE_STRING);
   sz = jerry_api_string_to_char_buffer (res.v_string, NULL, 0);
-  assert (sz == -5);
+  JERRY_ASSERT (sz == -5);
   sz = jerry_api_string_to_char_buffer (res.v_string, buffer, -sz);
-  assert (sz == 5);
+  JERRY_ASSERT (sz == 5);
   jerry_api_release_value (&res);
-  assert (!strcmp (buffer, "abcd"));
+  JERRY_ASSERT (!strcmp (buffer, "abcd"));
 
   // Get global.A
   is_ok = jerry_api_get_object_field_value (global_obj_p, "A", &val_A);
-  assert (is_ok
-          && val_A.type == JERRY_API_DATA_TYPE_OBJECT);
+  JERRY_ASSERT (is_ok
+                && val_A.type == JERRY_API_DATA_TYPE_OBJECT);
 
   // Get A.prototype
   is_ok = jerry_api_is_constructor (val_A.v_object);
-  assert (is_ok);
+  JERRY_ASSERT (is_ok);
   is_ok = jerry_api_get_object_field_value (val_A.v_object,
                                             "prototype",
                                             &val_A_prototype);
-  assert (is_ok
-          && val_A_prototype.type == JERRY_API_DATA_TYPE_OBJECT);
+  JERRY_ASSERT (is_ok
+                && val_A_prototype.type == JERRY_API_DATA_TYPE_OBJECT);
   jerry_api_release_value (&val_A);
 
   // Set A.prototype.foo = global.foo
   is_ok = jerry_api_set_object_field_value (val_A_prototype.v_object,
                                             "foo",
                                             &val_foo);
-  assert (is_ok);
+  JERRY_ASSERT (is_ok);
   jerry_api_release_value (&val_A_prototype);
   jerry_api_release_value (&val_foo);
 
   // Get global.a
   is_ok = jerry_api_get_object_field_value (global_obj_p, "a", &val_a);
-  assert (is_ok
-          && val_a.type == JERRY_API_DATA_TYPE_OBJECT);
+  JERRY_ASSERT (is_ok
+                && val_a.type == JERRY_API_DATA_TYPE_OBJECT);
 
   // Get a.t
   is_ok = jerry_api_get_object_field_value (val_a.v_object, "t", &res);
-  assert (is_ok
-          && res.type == JERRY_API_DATA_TYPE_FLOAT64
-          && res.v_float64 == 12.0);
+  JERRY_ASSERT (is_ok
+                && res.type == JERRY_API_DATA_TYPE_FLOAT64
+                && res.v_float64 == 12.0);
   jerry_api_release_value (&res);
 
   // Get a.foo
   is_ok = jerry_api_get_object_field_value (val_a.v_object, "foo", &val_a_foo);
-  assert (is_ok
-          && val_a_foo.type == JERRY_API_DATA_TYPE_OBJECT);
+  JERRY_ASSERT (is_ok
+                && val_a_foo.type == JERRY_API_DATA_TYPE_OBJECT);
 
   // Call a.foo ()
   is_ok = jerry_api_call_function (val_a_foo.v_object, val_a.v_object, &res, NULL, 0);
-  assert (is_ok
-          && res.type == JERRY_API_DATA_TYPE_FLOAT64
-          && res.v_float64 == 12.0);
+  JERRY_ASSERT (is_ok
+                && res.type == JERRY_API_DATA_TYPE_FLOAT64
+                && res.v_float64 == 12.0);
   jerry_api_release_value (&res);
   jerry_api_release_value (&val_a_foo);
 
@@ -346,95 +343,95 @@ main (void)
 
   // Create native handler bound function object and set it to 'external' variable
   external_func_p = jerry_api_create_external_function (handler);
-  assert (external_func_p != NULL
-          && jerry_api_is_function (external_func_p)
-          && jerry_api_is_constructor (external_func_p));
+  JERRY_ASSERT (external_func_p != NULL
+                && jerry_api_is_function (external_func_p)
+                && jerry_api_is_constructor (external_func_p));
 
   test_api_init_api_value_object (&val_external, external_func_p);
   is_ok = jerry_api_set_object_field_value (global_obj_p,
                                             "external",
                                             &val_external);
-  assert (is_ok);
+  JERRY_ASSERT (is_ok);
   jerry_api_release_value (&val_external);
   jerry_api_release_object (external_func_p);
 
   // Call 'call_external' function that should call external function created above
   is_ok = jerry_api_get_object_field_value (global_obj_p, "call_external", &val_call_external);
-  assert (is_ok
-          && val_call_external.type == JERRY_API_DATA_TYPE_OBJECT);
+  JERRY_ASSERT (is_ok
+                && val_call_external.type == JERRY_API_DATA_TYPE_OBJECT);
   is_ok = jerry_api_call_function (val_call_external.v_object,
                                    global_obj_p,
                                    &res,
                                    NULL, 0);
   jerry_api_release_value (&val_call_external);
-  assert (is_ok
-          && res.type == JERRY_API_DATA_TYPE_STRING);
+  JERRY_ASSERT (is_ok
+                && res.type == JERRY_API_DATA_TYPE_STRING);
   sz = jerry_api_string_to_char_buffer (res.v_string, NULL, 0);
-  assert (sz == -20);
+  JERRY_ASSERT (sz == -20);
   sz = jerry_api_string_to_char_buffer (res.v_string, buffer, -sz);
-  assert (sz == 20);
+  JERRY_ASSERT (sz == 20);
   jerry_api_release_value (&res);
-  assert (!strcmp (buffer, "string from handler"));
+  JERRY_ASSERT (!strcmp (buffer, "string from handler"));
 
   // Create native handler bound function object and set it to 'external_construct' variable
   external_construct_p = jerry_api_create_external_function (handler_construct);
-  assert (external_construct_p != NULL
-          && jerry_api_is_function (external_construct_p)
-          && jerry_api_is_constructor (external_construct_p));
+  JERRY_ASSERT (external_construct_p != NULL
+                && jerry_api_is_function (external_construct_p)
+                && jerry_api_is_constructor (external_construct_p));
 
   test_api_init_api_value_object (&val_external_construct, external_construct_p);
   is_ok = jerry_api_set_object_field_value (global_obj_p,
                                             "external_construct",
                                             &val_external_construct);
-  assert (is_ok);
+  JERRY_ASSERT (is_ok);
   jerry_api_release_value (&val_external_construct);
   jerry_api_release_object (external_construct_p);
 
   // Call external function created above, as constructor
   test_api_init_api_value_bool (&args[0], true);
   is_ok = jerry_api_construct_object (external_construct_p, &res, args, 1);
-  assert (is_ok
-          && res.type == JERRY_API_DATA_TYPE_OBJECT);
+  JERRY_ASSERT (is_ok
+                && res.type == JERRY_API_DATA_TYPE_OBJECT);
   is_ok = jerry_api_get_object_field_value (res.v_object,
                                             "value_field",
                                             &val_value_field);
 
   // Get 'value_field' of constructed object
-  assert (is_ok
-          && val_value_field.type == JERRY_API_DATA_TYPE_BOOLEAN
-          && val_value_field.v_bool == true);
+  JERRY_ASSERT (is_ok
+                && val_value_field.type == JERRY_API_DATA_TYPE_BOOLEAN
+                && val_value_field.v_bool == true);
   jerry_api_release_value (&val_value_field);
 
   uintptr_t ptr;
   is_ok = jerry_api_get_object_native_handle (res.v_object, &ptr);
-  assert (is_ok
-          && ptr == (uintptr_t) 0x0012345678abcdefull);
+  JERRY_ASSERT (is_ok
+                && ptr == (uintptr_t) 0x0012345678abcdefull);
 
   jerry_api_release_value (&res);
 
 
   // Test: Throwing exception from native handler.
   throw_test_handler_p = jerry_api_create_external_function (handler_throw_test);
-  assert (throw_test_handler_p != NULL
-          && jerry_api_is_function (throw_test_handler_p));
+  JERRY_ASSERT (throw_test_handler_p != NULL
+                && jerry_api_is_function (throw_test_handler_p));
 
   test_api_init_api_value_object (&val_t, throw_test_handler_p);
   is_ok = jerry_api_set_object_field_value (global_obj_p,
                                             "throw_test",
                                             &val_t);
-  assert (is_ok);
+  JERRY_ASSERT (is_ok);
   jerry_api_release_value (&val_t);
   jerry_api_release_object (throw_test_handler_p);
 
   is_ok = jerry_api_get_object_field_value (global_obj_p, "call_throw_test", &val_t);
-  assert (is_ok
-          && val_t.type == JERRY_API_DATA_TYPE_OBJECT);
+  JERRY_ASSERT (is_ok
+                && val_t.type == JERRY_API_DATA_TYPE_OBJECT);
 
   is_ok = jerry_api_call_function (val_t.v_object,
                                    global_obj_p,
                                    &res,
                                    NULL, 0);
-  assert (is_ok);
+  JERRY_ASSERT (is_ok);
   jerry_api_release_value (&val_t);
   jerry_api_release_value (&res);
 
@@ -444,7 +441,7 @@ main (void)
 
   jerry_cleanup ();
 
-  assert (test_api_is_free_callback_was_called);
+  JERRY_ASSERT (test_api_is_free_callback_was_called);
 
   // External Magic String
   jerry_init (JERRY_FLAG_SHOW_OPCODES);
@@ -456,10 +453,10 @@ main (void)
 
   const char *ms_code_src_p = "var global = {}; var console = [1]; var process = 1;";
   is_ok = jerry_parse (ms_code_src_p, strlen (ms_code_src_p));
-  assert (is_ok);
+  JERRY_ASSERT (is_ok);
 
   is_ok = (jerry_run () == JERRY_COMPLETION_CODE_OK);
-  assert (is_ok);
+  JERRY_ASSERT (is_ok);
 
   jerry_cleanup ();
 
diff --git a/tests/unit/test-common.h b/tests/unit/test-common.h
new file mode 100644
index 0000000000..c56f71c048
--- /dev/null
+++ b/tests/unit/test-common.h
@@ -0,0 +1,46 @@
+/* Copyright 2014-2015 Samsung Electronics Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TEST_COMMON_H
+#define TEST_COMMON_H
+
+#include "jrt.h"
+
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+
+using namespace std;
+
+#define TEST_RANDOMIZE() \
+do \
+{ \
+  struct timeval current_time; \
+  gettimeofday (&current_time, NULL); \
+  \
+  time_t seconds = current_time.tv_sec; \
+  suseconds_t microseconds = current_time.tv_usec; \
+  \
+  uint32_t seed = (uint32_t) (seconds + microseconds); \
+  \
+  printf ("TEST_RANDOMIZE: seed is %u\n", seed); \
+  \
+  srand (seed); \
+} \
+while (0)
+
+#endif /* TEST_COMMON_H */
diff --git a/tests/unit/test_heap.cpp b/tests/unit/test-heap.cpp
similarity index 91%
rename from tests/unit/test_heap.cpp
rename to tests/unit/test-heap.cpp
index 46830fecaf..78700d6b01 100644
--- a/tests/unit/test_heap.cpp
+++ b/tests/unit/test-heap.cpp
@@ -13,17 +13,9 @@
  * limitations under the License.
  */
 
-#include "jrt.h"
 #include "mem-allocator.h"
 
-extern "C"
-{
-  extern void srand (unsigned int __seed);
-  extern int rand (void);
-  extern long int time (long int *__timer);
-  extern int printf (__const char *__restrict __format, ...);
-  extern void *memset (void *__s, int __c, size_t __n);
-}
+#include "test-common.h"
 
 // Heap size is 32K
 #define test_heap_size (32 * 1024)
@@ -90,12 +82,9 @@ int
 main (int __attr_unused___ argc,
       char __attr_unused___ **argv)
 {
-  mem_heap_init (test_native_heap, sizeof (test_native_heap));
+  TEST_RANDOMIZE ();
 
-  srand ((unsigned int) time (NULL));
-  int k = rand ();
-  printf ("seed=%d\n", k);
-  srand ((unsigned int) k);
+  mem_heap_init (test_native_heap, sizeof (test_native_heap));
 
   mem_register_a_try_give_memory_back_callback (test_heap_give_some_memory_back);
 
diff --git a/tests/unit/test_literal_storage.cpp b/tests/unit/test-literal-storage.cpp
similarity index 90%
rename from tests/unit/test_literal_storage.cpp
rename to tests/unit/test-literal-storage.cpp
index d052d08cfc..28b9a2cccc 100644
--- a/tests/unit/test_literal_storage.cpp
+++ b/tests/unit/test-literal-storage.cpp
@@ -16,17 +16,7 @@
 #include "ecma-helpers.h"
 #include "lit-literal.h"
 
-extern "C"
-{
-  extern void srand (unsigned int __seed);
-  extern int rand (void);
-  extern long int time (long int *__timer);
-  extern int printf (__const char *__restrict __format, ...);
-  extern void *memset (void *__s, int __c, size_t __n);
-}
-
-// Heap size is 32K
-#define test_heap_size (32 * 1024)
+#include "test-common.h"
 
 // Iterations count
 #define test_iters 64
@@ -68,6 +58,8 @@ int
 main (int __attr_unused___ argc,
       char __attr_unused___ **argv)
 {
+  TEST_RANDOMIZE ();
+
   const ecma_char_t *ptrs[test_sub_iters];
   ecma_number_t numbers[test_sub_iters];
   ecma_char_t strings[test_sub_iters][max_characters_in_string + 1];
@@ -76,10 +68,6 @@ main (int __attr_unused___ argc,
   mem_init ();
   lit_init ();
 
-  srand ((unsigned int) time (NULL));
-  int k = rand ();
-  printf ("seed=%d\n", k);
-  srand ((unsigned int) k);
 
   for (uint32_t i = 0; i < test_iters; i++)
   {
diff --git a/tests/unit/test_number_to_string.cpp b/tests/unit/test-number-to-string.cpp
similarity index 97%
rename from tests/unit/test_number_to_string.cpp
rename to tests/unit/test-number-to-string.cpp
index fafc290d55..e736a02fda 100644
--- a/tests/unit/test_number_to_string.cpp
+++ b/tests/unit/test-number-to-string.cpp
@@ -13,12 +13,10 @@
  * limitations under the License.
  */
 
-#include <math.h>
-#include <string.h>
-
 #include "ecma-globals.h"
 #include "ecma-helpers.h"
-#include "jrt.h"
+
+#include "test-common.h"
 
 /**
  * Unit test's main function.
diff --git a/tests/unit/test_preparser.cpp b/tests/unit/test-parser.cpp
similarity index 68%
rename from tests/unit/test_preparser.cpp
rename to tests/unit/test-parser.cpp
index d551bb8aec..48f9963f4e 100644
--- a/tests/unit/test_preparser.cpp
+++ b/tests/unit/test-parser.cpp
@@ -13,15 +13,55 @@
  * limitations under the License.
  */
 
-#include <string.h>
-
-#include "jrt.h"
 #include "mem-allocator.h"
 #include "opcodes.h"
-#include "common.h"
 #include "parser.h"
 #include "serializer.h"
 
+#include "test-common.h"
+
+#define NAME_TO_ID(op) (__op__idx_##op)
+
+#define __OPCODE_SIZE(name, arg1, arg2, arg3) \
+  (uint8_t) (sizeof (__op_##name) + 1),
+
+static uint8_t opcode_sizes[] =
+{
+  OP_LIST (OPCODE_SIZE)
+  0
+};
+
+static bool
+opcodes_equal (const opcode_t *opcodes1, opcode_t *opcodes2, uint16_t size)
+{
+  uint16_t i;
+  for (i = 0; i < size; i++)
+  {
+    uint8_t opcode_num1 = opcodes1[i].op_idx, opcode_num2 = opcodes2[i].op_idx;
+    uint8_t j;
+
+    if (opcode_num1 != opcode_num2)
+    {
+      return false;
+    }
+
+    if (opcode_num1 == NAME_TO_ID (nop) || opcode_num1 == NAME_TO_ID (ret))
+    {
+      return true;
+    }
+
+    for (j = 1; j < opcode_sizes[opcode_num1]; j++)
+    {
+      if (((uint8_t*)&opcodes1[i])[j] != ((uint8_t*)&opcodes2[i])[j])
+      {
+        return false;
+      }
+    }
+  }
+
+  return true;
+}
+
 /**
  * Unit test's main function.
  */
diff --git a/tests/unit/test_pool.cpp b/tests/unit/test-pool.cpp
similarity index 85%
rename from tests/unit/test_pool.cpp
rename to tests/unit/test-pool.cpp
index 2e2e2dd950..d22d190a6f 100644
--- a/tests/unit/test_pool.cpp
+++ b/tests/unit/test-pool.cpp
@@ -15,19 +15,11 @@
 
 #define JERRY_MEM_POOL_INTERNAL
 
-#include "jrt.h"
 #include "mem-allocator.h"
 #include "mem-pool.h"
 #include "mem-poolman.h"
 
-extern "C"
-{
-  extern void srand (unsigned int __seed);
-  extern int rand (void);
-  extern long int time (long int *__timer);
-  extern int printf (__const char *__restrict __format, ...);
-  extern void *memset (void *__s, int __c, size_t __n);
-}
+#include "test-common.h"
 
 // Iterations count
 const uint32_t test_iters = 64;
@@ -45,10 +37,7 @@ int
 main (int __attr_unused___ argc,
       char __attr_unused___ **argv)
 {
-  srand ((unsigned int) time (NULL));
-  int k = rand ();
-  printf ("seed=%d\n", k);
-  srand ((unsigned int) k);
+  TEST_RANDOMIZE ();
 
   for (uint32_t i = 0; i < test_iters; i++)
   {
diff --git a/tests/unit/test_poolman.cpp b/tests/unit/test-poolman.cpp
similarity index 90%
rename from tests/unit/test_poolman.cpp
rename to tests/unit/test-poolman.cpp
index 7527bb23f9..2076bd6761 100644
--- a/tests/unit/test_poolman.cpp
+++ b/tests/unit/test-poolman.cpp
@@ -17,18 +17,14 @@
  * Unit test for pool manager.
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-
 #define JERRY_MEM_POOL_INTERNAL
 
-#include "jrt.h"
 #include "mem-allocator.h"
 #include "mem-pool.h"
 #include "mem-poolman.h"
 
+#include "test-common.h"
+
 // Iterations count
 const uint32_t test_iters = 16384;
 
@@ -41,12 +37,9 @@ int
 main (int __attr_unused___ argc,
       char __attr_unused___ **argv)
 {
-  mem_init ();
+  TEST_RANDOMIZE ();
 
-  srand ((unsigned int) time (NULL));
-  unsigned int seed = (unsigned int) rand ();
-  printf ("seed=%u\n", seed);
-  srand (seed);
+  mem_init ();
 
   for (uint32_t i = 0; i < test_iters; i++)
   {
diff --git a/tests/unit/test_recordset.cpp b/tests/unit/test-recordset.cpp
similarity index 96%
rename from tests/unit/test_recordset.cpp
rename to tests/unit/test-recordset.cpp
index 7089e9b549..86e4b93777 100644
--- a/tests/unit/test_recordset.cpp
+++ b/tests/unit/test-recordset.cpp
@@ -13,18 +13,10 @@
  * limitations under the License.
  */
 
-#include "jrt.h"
 #include "mem-allocator.h"
 #include "rcs-recordset.h"
 
-extern "C"
-{
-  extern void srand (unsigned int __seed);
-  extern int rand (void);
-  extern long int time (long int *__timer);
-  extern int printf (__const char *__restrict __format, ...);
-  extern void *memset (void *__s, int __c, size_t __n);
-}
+#include "test-common.h"
 
 // Heap size is 32K
 #define test_heap_size (32 * 1024)
@@ -221,10 +213,7 @@ int
 main (int __attr_unused___ argc,
       char __attr_unused___ **argv)
 {
-  srand ((unsigned int) time (NULL));
-  int k = rand ();
-  printf ("seed=%d\n", k);
-  srand ((unsigned int) k);
+  TEST_RANDOMIZE ();
 
   mem_init ();
 
diff --git a/tests/unit/test_string_to_number.cpp b/tests/unit/test-string-to-number.cpp
similarity index 98%
rename from tests/unit/test_string_to_number.cpp
rename to tests/unit/test-string-to-number.cpp
index cafdd1f43f..fd46982077 100644
--- a/tests/unit/test_string_to_number.cpp
+++ b/tests/unit/test-string-to-number.cpp
@@ -13,11 +13,10 @@
  * limitations under the License.
  */
 
-#include <math.h>
-
 #include "ecma-globals.h"
 #include "ecma-helpers.h"
-#include "jrt.h"
+
+#include "test-common.h"
 
 /**
  * Unit test's main function.
diff --git a/tools/runners/run-unittests.sh b/tools/runners/run-unittests.sh
index 51d8e743ee..f2c389675d 100755
--- a/tools/runners/run-unittests.sh
+++ b/tools/runners/run-unittests.sh
@@ -30,7 +30,7 @@ done
 
 rm -f $DIR/unit_tests_run.log
 
-UNITTESTS=$(ls $DIR/unit_*)
+UNITTESTS=$(ls $DIR/unit-*)
 
 for unit_test in $UNITTESTS;
 do