diff --git a/test/test.c b/lib/assert.c
similarity index 79%
rename from test/test.c
rename to lib/assert.c
index d2b5310..8c3b17e 100644
--- a/test/test.c
+++ b/lib/assert.c
@@ -1,7 +1,7 @@
-#include "test.h"
+#include "assert.h"
 
 bool assert_string_equal(const string_t actual, const string_t expected) {
-  if (strcmp(expected, actual) != 0) {
+  if (!string_equals(actual, expected)) {
     printf("FAIL: expected = \"%s\" ; actual = \"%s\"\n", expected, actual);
     return false;
   }
@@ -9,7 +9,7 @@ bool assert_string_equal(const string_t actual, const string_t expected) {
 }
 
 bool assert_string_not_equal(const string_t actual, const string_t expected) {
-  if (strcmp(expected, actual) == 0) {
+  if (string_equals(actual, expected)) {
     printf("FAIL: expected = \"%s\" ; actual = \"%s\"\n", expected, actual);
     return false;
   }
diff --git a/lib/assert.h b/lib/assert.h
new file mode 100644
index 0000000..871a41f
--- /dev/null
+++ b/lib/assert.h
@@ -0,0 +1,30 @@
+#ifndef __LIBCPROJECT_ASSERT__
+#define __LIBCPROJECT_ASSERT__
+
+#include <assert.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include "string.h"
+#include "types.h"
+
+/**
+ * @brief Check if the two strings are equal. If they are not equal, print the expected and actual strings.
+ *
+ * @param character
+ * @return bool
+ * @since v5.0.0
+ */
+bool assert_string_equal(const string_t actual, const string_t expected);
+
+/**
+ * @brief Check if the two strings are not equal. If they are equal, print the expected and actual strings.
+ *
+ * @param character
+ * @return bool
+ * @since v5.0.0
+ */
+bool assert_string_not_equal(const string_t actual, const string_t expected);
+
+#endif
diff --git a/lib/character.h b/lib/character.h
index f1f7374..724f624 100644
--- a/lib/character.h
+++ b/lib/character.h
@@ -48,8 +48,7 @@ char character_to_lower(const char character);
  * @brief Check if the character is a digit ('0', '1', '2', '3', '4', '5', '6', '7, '8' or '9').
  *
  * @param character
- * @return true
- * @return false
+ * @return bool
  * @since v1.0.0
  */
 bool character_get_is_digit(const char character);
diff --git a/lib/filesystem.h b/lib/filesystem.h
index 2ebe051..ea0098f 100644
--- a/lib/filesystem.h
+++ b/lib/filesystem.h
@@ -43,8 +43,7 @@ int filesystem_write(string_t path, byte_t *file_content, size_t file_size);
  * @brief Check if a path exists.
  *
  * @param path
- * @return true
- * @return false
+ * @return bool
  * @since v3.1.0
  */
 bool filesystem_exists(string_t path);
diff --git a/lib/hash_map.h b/lib/hash_map.h
index cc4b086..e9df556 100644
--- a/lib/hash_map.h
+++ b/lib/hash_map.h
@@ -85,8 +85,7 @@ void *hash_map_get(struct hash_map *hash_map, string_t key);
  *
  * @param hash_map
  * @param key
- * @return true
- * @return false
+ * @return bool
  * @since v2.0.0
  */
 bool hash_map_contains_key(struct hash_map *hash_map, string_t key);
diff --git a/lib/mathematics.h b/lib/mathematics.h
index 2d693df..fc1e0f5 100644
--- a/lib/mathematics.h
+++ b/lib/mathematics.h
@@ -14,8 +14,7 @@
  *
  * @param number1
  * @param number2
- * @return true
- * @return false
+ * @return bool
  * @since v1.0.0
  */
 bool mathematics_equals(const float64_t number1, const float64_t number2);
diff --git a/libcproject.h b/libcproject.h
index 844de1b..8554757 100644
--- a/libcproject.h
+++ b/libcproject.h
@@ -2,6 +2,7 @@
 #define __LIBCPROJECT__
 
 #include "lib/array_list.h"
+#include "lib/assert.h"
 #include "lib/character.h"
 #include "lib/convert.h"
 #include "lib/date.h"
diff --git a/test/character_test.h b/test/character_test.h
index 2a02770..9e18685 100644
--- a/test/character_test.h
+++ b/test/character_test.h
@@ -6,7 +6,6 @@
 #include <stdlib.h>
 
 #include "libcproject.h"
-#include "test.h"
 
 void character_test();
 
diff --git a/test/convert_test.h b/test/convert_test.h
index 8eb6889..8e9c0ff 100644
--- a/test/convert_test.h
+++ b/test/convert_test.h
@@ -6,7 +6,6 @@
 #include <stdlib.h>
 
 #include "libcproject.h"
-#include "test.h"
 
 void convert_test();
 
diff --git a/test/date_test.h b/test/date_test.h
index 3d9ddaf..d3ec9b7 100644
--- a/test/date_test.h
+++ b/test/date_test.h
@@ -4,7 +4,6 @@
 #include <assert.h>
 
 #include "libcproject.h"
-#include "test.h"
 
 void date_test();
 
diff --git a/test/string_test.h b/test/string_test.h
index bcef767..70a547a 100644
--- a/test/string_test.h
+++ b/test/string_test.h
@@ -6,7 +6,6 @@
 #include <stdlib.h>
 
 #include "libcproject.h"
-#include "test.h"
 
 void string_test();
 
diff --git a/test/test.h b/test/test.h
deleted file mode 100644
index 50c9fa8..0000000
--- a/test/test.h
+++ /dev/null
@@ -1,14 +0,0 @@
-#ifndef __TEST__
-#define __TEST__
-
-#include <stdbool.h>
-#include <stdio.h>
-#include <string.h>
-
-#include "libcproject.h"
-
-bool assert_string_equal(const string_t actual, const string_t expected);
-
-bool assert_string_not_equal(const string_t actual, const string_t expected);
-
-#endif