test with kerkour architecture (https://kerkour.com/rust-web-application-clean-architecture)

src/scalar.rs

@@ -0,0 +1,10 @@
+/// It is easier to track each type alias if this file is located on the top-level directory (here)
+/// than in each domain. Also, separating them will create a lot of duplicate code.
+use uuid::Uuid;
+
+pub type Time = chrono::DateTime<chrono::Utc>;
+
+/// The ID scalar type represents a unique identifier, often used to refetch an object or as key for a cache.
+/// The ID type appears in a JSON response as a String; however, it is not intended to be human-readable.
+/// When expected as an input type, any string (such as "4") or integer (such as 4) input value will be accepted as an ID.
+pub type Id = Uuid;