feat(typed-uuid): add new_unchecked fn

benzina/Cargo.toml

@@ -10,7 +10,14 @@ repository.workspace = true
 rust-version.workspace = true
 
 [package.metadata.docs.rs]
-features = ["postgres", "mysql", "serde", "typed-uuid", "example-generated"]
+features = [
+    "postgres",
+    "mysql",
+    "serde",
+    "typed-uuid",
+    "example-generated",
+    "dangerous-construction",
+]
 rustdoc-args = ["--cfg", "docsrs"]
 
 [dependencies]
@@ -21,7 +28,8 @@ benzina-derive = { path = "../benzina-derive", version = "=0.3.3", optional = tr
 uuid = { version = ">=0.7.0, <2.0.0", default-features = false, optional = true }
 
 [dev-dependencies]
-serde_test =  "1"
+serde_test = "1"
+uuid = { version = ">=0.7.0, <2.0.0", default-features = false, features = ["v4"] }
 
 [features]
 default = ["derive"]
@@ -35,6 +43,7 @@ serde = ["dep:serde", "uuid?/serde"]
 utoipa = ["dep:utoipa"]
 
 example-generated = ["typed-uuid"]
+dangerous-construction = ["typed-uuid"]
 
 [lints]
 workspace = true

benzina/src/typed_uuid.rs

@@ -4,7 +4,7 @@
 /// generates code which implements many useful traits, including the ones needed to work with
 /// [`diesel`].
 ///
-/// The generated structs do not expose any method or trait to create an arbitrary instance, in
+/// The generated structs do not expose any method or trait to create an arbitrary instance[^See note], in
 /// order to provide the guarantee that the `UUID` is valid. However, it is possible to choose to
 /// add traits and methods to customize the behavior.
 ///
@@ -48,7 +48,7 @@
 /// }
 /// ```
 ///
-/// Keep in mind that there is no way to construct an instance unless the instantiation is done
+/// Keep in mind that there is no way[^See note] to construct an instance unless the instantiation is done
 /// inside the module containing the new type or a submodule of it:
 ///
 /// ```compile_fail,E0603
@@ -62,6 +62,12 @@
 /// let foo = inner::Foo(Uuid::default());
 /// //               ^^^ private tuple struct constructor
 /// ```
+///
+/// [^See note]: There is no way in normal usage to construct an instance. The exception is with the
+/// `dangerous_new` method, which is gated behind the `dangerous-construction` feature and intended
+/// for special cases (including testing). If the `dangerous-construction` feature is enabled, it is
+/// recommended to use [`clippy::disallowed_methods`](https://rust-lang.github.io/rust-clippy/stable/index.html#disallowed_methods) to prevent the usage of `dangerous_new` outside
+/// of the desired situations.
 #[macro_export]
 macro_rules! typed_uuid {
     (
@@ -85,6 +91,15 @@ macro_rules! typed_uuid {
             $vis struct $name($crate::__private::uuid::Uuid);
 
             impl $name {
+                /// Creates a new typed [`Uuid`] which does not come from the database.
+                ///
+                /// [`Uuid`]: $crate::__private::uuid::Uuid
+                #[must_use]
+                #[cfg(feature = "dangerous-construction")]
+                pub fn dangerous_new(inner: $crate::__private::uuid::Uuid) -> Self {
+                    Self(inner)
+                }
+
                 /// Gets the actual [`Uuid`].
                 ///
                 /// [`Uuid`]: $crate::__private::uuid::Uuid
@@ -361,3 +376,16 @@ macro_rules! __typed_uuid__impl_serde {
 macro_rules! __typed_uuid__impl_serde {
     ($name:ident) => {};
 }
+
+#[cfg(test)]
+mod test {
+    use uuid::Uuid;
+
+    #[test]
+    fn creates_new_typed_uuid() {
+        crate::typed_uuid!(pub FooId);
+        let inner = Uuid::new_v4();
+        let new = FooId::dangerous_new(inner);
+        assert_eq!(new.get(), inner);
+    }
+}