diff --git a/src/main.rs b/src/main.rs
index 6d12ddd..a27e2b3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -41,3 +41,32 @@ fn open_file(filename: &str) -> io::Result<String> {
 fn main() {
     let conf = open_file("two_robots.txt");
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_orientation() {
+        assert!(parse_orientation('N').is_ok());
+        assert!(parse_orientation('E').is_ok());
+        assert!(parse_orientation('S').is_ok());
+        assert!(parse_orientation('W').is_ok());
+        assert!(parse_orientation('Z').is_err());
+    }
+
+    #[test]
+    fn test_parse_instruction() {
+        assert!(parse_instruction('L').is_ok());
+        assert!(parse_instruction('R').is_ok());
+        assert!(parse_instruction('F').is_ok());
+        assert!(parse_instruction('Z').is_err());
+    }
+
+    #[test]
+    fn test_open_file() {
+        assert!(open_file("two_robots.txt").is_ok());
+        assert!(open_file("test_unexisting_file.extension").is_err());
+    }
+
+}