added testing module to the controllers

src/controllers.rs

@@ -3,3 +3,15 @@ use actix_web::{HttpRequest, Responder};
 pub fn index(_req: &HttpRequest) -> impl Responder {
     "Hello world!"
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use actix_web::{http, test};
+
+    #[test]
+    fn test_index() {
+        let resp = test::TestRequest::default().run(&index).unwrap();
+        assert_eq!(resp.status(), http::StatusCode::OK);
+    }
+}