diff --git a/.vscode/c_cpp_properties.json b/.vscode/c_cpp_properties.json
new file mode 100644
index 0000000..5703028
--- /dev/null
+++ b/.vscode/c_cpp_properties.json
@@ -0,0 +1,17 @@
+{
+    "configurations": [
+        {
+            "name": "Linux",
+            "includePath": [
+                "${workspaceFolder}/**",
+                "/usr/include/libftdi1"
+            ],
+            "defines": [],
+            "compilerPath": "/usr/bin/clang",
+            "cStandard": "c11",
+            "cppStandard": "c++17",
+            "intelliSenseMode": "clang-x64"
+        }
+    ],
+    "version": 4
+}
\ No newline at end of file
diff --git a/.vscode/launch.json b/.vscode/launch.json
index 06a2d90..09caaf0 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -8,7 +8,7 @@
             "name": "(gdb) Launch",
             "type": "cppdbg",
             "request": "launch",
-            "program": "${workspaceFolder}/bin/test",
+            "program": "${workspaceFolder}/bin/test/unit/gpio_ftdi",
             "args": [],
             "stopAtEntry": false,
             "cwd": "${workspaceFolder}",
diff --git a/src/gpio.c b/src/gpio.c
index 4659398..9bc93c4 100644
--- a/src/gpio.c
+++ b/src/gpio.c
@@ -1,3 +1,4 @@
+#include <assert.h>
 #include <stdlib.h>
 #include <syslog.h>
 #include <stdbool.h>
@@ -38,11 +39,7 @@ int gpio_open(const struct gpio *gpio)
     int res;
     unsigned char init_value = 0;
 
-    if(NULL == gpio) {
-        syslog(LOG_ERR, "No valid gpio object given.\n");
-        return EXIT_FAILURE;
-    }
-
+    assert(NULL != gpio);
     if(!gpio->ftdi_dev->is_open) {
         res = ftdi_open(gpio);
         if(res != EXIT_SUCCESS) {
@@ -76,9 +73,7 @@ int gpio_open(const struct gpio *gpio)
 // cppcheck-suppress unusedFunction
 int gpio_close(const struct gpio *gpio)
 {
-    if(NULL == gpio) {
-        return EXIT_FAILURE;
-    }
+    assert(NULL != gpio);
 
     gpio_write(gpio, 0);
 
@@ -95,9 +90,8 @@ int gpio_close(const struct gpio *gpio)
 // cppcheck-suppress unusedFunction
 int gpio_read(const struct gpio *gpio, unsigned int *value)
 {
-    if(NULL == gpio || NULL == value) {
-        return EXIT_FAILURE;
-    }
+    assert(NULL != gpio);
+    assert(NULL != value);
 
     if(gpio->ftdi_dev->status_mask & (unsigned char)(gpio->pin)) {
         *value = 1;
@@ -113,9 +107,7 @@ int gpio_write(const struct gpio *gpio, unsigned int value)
     int res;
     unsigned char mask;
 
-    if(NULL == gpio) {
-        return EXIT_FAILURE;
-    }
+    assert(NULL != gpio);
 
     mask = gpio->ftdi_dev->status_mask;
 
@@ -143,9 +135,7 @@ int gpio_toggle(const struct gpio *gpio)
     int res;
     unsigned char mask;
 
-    if(NULL == gpio) {
-        return EXIT_FAILURE;
-    }
+    assert(NULL != gpio);
 
     mask  = (gpio->ftdi_dev->status_mask) ^ (unsigned char)(gpio->pin);
 
diff --git a/test/unit/gpio_close.c b/test/unit/gpio_close.c
index 457c864..595469e 100644
--- a/test/unit/gpio_close.c
+++ b/test/unit/gpio_close.c
@@ -9,10 +9,6 @@
 #include <ftdi_dev.h>
 #include <gpio.h>
 
-UTEST(gpio_close, invalid_gpio_obj) {
-    ASSERT_EQ(gpio_close(NULL), EXIT_FAILURE);
-}
-
 UTEST(gpio_close, empty_bitmask) {
     struct gpio gpio_1;
     struct ftdi_dev ftdi_obj;
diff --git a/test/unit/gpio_open.c b/test/unit/gpio_open.c
index c4297d3..3060761 100644
--- a/test/unit/gpio_open.c
+++ b/test/unit/gpio_open.c
@@ -89,10 +89,6 @@ UTEST(gpio_open, ftdi_open_success) {
     ASSERT_EQ(gpio_open(&gpio_1), EXIT_SUCCESS);
 }
 
-UTEST(gpio_open, invalid_gpio_obj) {
-    ASSERT_EQ(gpio_open(NULL), EXIT_FAILURE);
-}
-
 UTEST(gpio_open, ftdi_set_bitmode_failed) {
     struct gpio gpio_1;
     struct ftdi_dev ftdi_obj;
diff --git a/test/unit/gpio_read.c b/test/unit/gpio_read.c
index a110f22..b8b5688 100644
--- a/test/unit/gpio_read.c
+++ b/test/unit/gpio_read.c
@@ -11,11 +11,6 @@
 
 #include <stdio.h>
 
-UTEST(gpio_read, invalid_params) {
-
-    ASSERT_EQ(gpio_read(NULL, NULL), EXIT_FAILURE);
-}
-
 UTEST(gpio_read, value_0) {
     unsigned int result;
     struct gpio gpio_1;
diff --git a/test/unit/gpio_toggle.c b/test/unit/gpio_toggle.c
index afd91aa..35531cc 100644
--- a/test/unit/gpio_toggle.c
+++ b/test/unit/gpio_toggle.c
@@ -11,11 +11,6 @@
 
 #include <stdio.h>
 
-UTEST(gpio_toggle, invalid_params) {
-
-    ASSERT_EQ(gpio_toggle(NULL), EXIT_FAILURE);
-}
-
 UTEST(gpio_toggle, ftdi_write_data_fails) {
     struct gpio gpio_1;
     struct ftdi_dev ftdi_obj;
diff --git a/test/unit/gpio_write.c b/test/unit/gpio_write.c
index ee0abac..95c80c3 100644
--- a/test/unit/gpio_write.c
+++ b/test/unit/gpio_write.c
@@ -9,11 +9,6 @@
 #include <ftdi_dev.h>
 #include <gpio.h>
 
-UTEST(gpio_write, invalid_params) {
-
-    ASSERT_EQ(gpio_write(NULL, 0), EXIT_FAILURE);
-}
-
 UTEST(gpio_write, value_0) {
     unsigned int result;
     struct gpio gpio_1;