diff --git a/test/server/prepare_start.c b/test/server/prepare_start.c
index 32c4565..bcaae4e 100644
--- a/test/server/prepare_start.c
+++ b/test/server/prepare_start.c
@@ -1,71 +1,90 @@
-#include <main.h>
 #include <cmocka.h>
+#include <main.h>
 #include <server.h>
 
-/* TODO: finish */
-
 int _errno = 0;
 int _exit_code = 0;
 extern void *print_str_arr;
 
 void __wrap_exit(int __status) { _exit_code = __status; }
 
-int __wrap_chdir(const char *__path) {
-    return mock_type(int);
-}
+int __wrap_chdir(const char *__path) { return mock_type(int); }
 
-int __wrap_mkdir(const char *__path, __mode_t __mode) {
-    return mock_type(int);
-}
+int __wrap_mkdir(const char *__path, __mode_t __mode) { return mock_type(int); }
 
-int __wrap_directory_exists(const char *path) {
-    return mock_type(int);
-}
+int __wrap_directory_exists(const char *path) { return mock_type(int); }
 
 void test__prepare_start__success(void **state) {
-    int argc = 2;
+  int argc = 2;
 
-    char *argv[] = {
-        "test_prog",
-        "w_dir"
-    };
+  char *argv[] = {"test_prog", "w_dir"};
 
-    will_return(__wrap_chdir, 0);
-    will_return(__wrap_directory_exists, 1);
+  will_return(__wrap_chdir, 0);
+  will_return(__wrap_directory_exists, 1);
 
-    prepare_start(argc,argv);
-    assert_int_equal(_exit_code, 0);
+  prepare_start(argc, argv);
+  assert_int_equal(_exit_code, 0);
 }
 
 void test__prepare_start__success_mkdir(void **state) {
-    int argc = 2;
+  int argc = 2;
 
-    char *argv[] = {
-        "test_prog",
-        "w_dir"
-    };
+  char *argv[] = {"test_prog", "w_dir"};
 
-    will_return(__wrap_chdir, 0);
-    will_return(__wrap_directory_exists, 0);
-    will_return(__wrap_mkdir, 1);
+  will_return(__wrap_chdir, 0);
+  will_return(__wrap_directory_exists, 0);
+  will_return(__wrap_mkdir, 1);
 
-    prepare_start(argc,argv);
-    assert_int_equal(_exit_code, 0);
+  prepare_start(argc, argv);
+  assert_int_equal(_exit_code, 0);
 }
 
-void test__prepare_start__success_no_arg(void **state) {
-    int argc = 1;
+void test__prepare_start__err_no_arg(void **state) {
+  int argc = 1;
 
-    char *argv[] = {
-        "test_prog"
-    };
+  char *argv[] = {"test_prog"};
 
-    will_return(__wrap_chdir, 0);
-    will_return(__wrap_directory_exists, 0);
-    will_return(__wrap_mkdir, 1);
+  const char *fmt_args[] = {"Usage: %s <work_dir>\n", argv[0] , NULL};
+  print_str_arr = fmt_args;
 
-    prepare_start(argc,argv);
-    assert_int_equal(_exit_code, 1);
+  will_return(__wrap_chdir, 0);
+  will_return(__wrap_directory_exists, 0);
+  will_return(__wrap_mkdir, 1);
+
+  prepare_start(argc, argv);
+  assert_int_equal(_exit_code, 1);
+}
+
+void test__prepare_start__err_chdir(void **state) {
+  int argc = 2;
+
+  char *argv[] = {"test_prog", "w_dir"};
+
+  const char *fmt_args[] = {"chdir: \"%s\" %s\n", argv[1], NULL};
+  print_str_arr = fmt_args;
+
+  will_return(__wrap_chdir, -1);
+  will_return(__wrap_directory_exists, 0);
+  will_return(__wrap_mkdir, 1);
+
+  prepare_start(argc, argv);
+  assert_int_equal(_exit_code, 2);
+}
+
+void test__prepare_start__err_mkdir(void **state) {
+  int argc = 2;
+
+  char *argv[] = {"test_prog", "w_dir"};
+
+  const char *fmt_args[] = {"chdir: \"%s\" %s\n", argv[1], NULL};
+  print_str_arr = fmt_args;
+
+  will_return(__wrap_chdir, -1);
+  will_return(__wrap_directory_exists, 0);
+  will_return(__wrap_mkdir, -1);
+
+  prepare_start(argc, argv);
+  assert_int_equal(_exit_code, 8);
 }
 
 int setup(void **state) {
@@ -78,6 +97,9 @@ int main(int argc, char **argv) {
   const struct CMUnitTest tests[] = {
       cmocka_unit_test(test__prepare_start__success),
       cmocka_unit_test(test__prepare_start__success_mkdir),
+      cmocka_unit_test(test__prepare_start__err_no_arg),
+      cmocka_unit_test(test__prepare_start__err_chdir),
+      cmocka_unit_test(test__prepare_start__err_mkdir),
   };
 
   return cmocka_run_group_tests(tests, setup, tear_down);
diff --git a/test/server/start_server.c b/test/server/start_server.c
index b73967c..5dd6d16 100644
--- a/test/server/start_server.c
+++ b/test/server/start_server.c
@@ -49,13 +49,13 @@ void test__start_server_success(void **state) {
 }
 
 void test__start_server_err_socket(void **state) {
-  _errno = EACCES;
   will_return(__wrap_socket, -1);
-
+  
   will_return(__wrap_setsockopt, 0);
   will_return(__wrap_bind, 0);
   will_return(__wrap_listen, 0);
-
+  
+  _errno = EACCES;
   const char *fmt_args[] = {"starting, socket: %s\n", strerror(_errno), NULL};
   print_str_arr = fmt_args;
   start_server();