refactoring: fmt preprocessing tests

src/preprocess.rs

@@ -50,11 +50,17 @@ mod tests {
     #[test]
     fn test_preprocessing_resolve_env_variable() {
         assert_eq!(preprocess("key=value".to_string()), Ok(None));
-        assert_eq!(preprocess("$key".to_string()), Ok(Some("value".to_string())))
+        assert_eq!(
+            preprocess("$key".to_string()),
+            Ok(Some("value".to_string()))
+        )
     }
 
     #[test]
     fn test_preprocessing_resolve_non_existent_env_variable() {
-        assert_eq!(preprocess("$nonexitent".to_string()), Ok(Some("".to_string())))
+        assert_eq!(
+            preprocess("$nonexitent".to_string()),
+            Ok(Some("".to_string()))
+        )
     }
 }