Example for seperate tests in tests directory

src/geometry.rs

@@ -51,6 +51,6 @@ mod tests {
     #[test]
     #[should_panic]
     fn foo() {
-        //panic!("This code panics!");
+        panic!("This code panics!");
     }
 }

tests/long_running_tests.rs

@@ -0,0 +1,2 @@
+#[test]
+fn very_long_running_test() {}