feat: Introduce UserId.clone.

This can be helpful when the `user_id` is dropped on the Rust side.

src/identifiers.rs

@@ -53,6 +53,12 @@ impl UserId {
     pub fn to_string(&self) -> String {
         self.inner.as_str().to_owned()
     }
+
+    /// Clone this `UserId`.
+    #[wasm_bindgen(js_name = "clone")]
+    pub fn clone_me(&self) -> Self {
+        self.clone()
+    }
 }
 
 /// A Matrix key ID.

tests/machine.test.ts

@@ -242,7 +242,7 @@ describe(OlmMachine.name, () => {
     test("can update tracked users", async () => {
         const m = await machine();
 
-        expect(await m.updateTrackedUsers([new UserId("@alice:example.org")])).toStrictEqual(undefined);
+        expect(await m.updateTrackedUsers([user.clone()])).toStrictEqual(undefined);
     });
 
     test("can receive sync changes", async () => {
@@ -509,7 +509,9 @@ describe(OlmMachine.name, () => {
         });
 
         test("can share a room key", async () => {
-            const requests = await m.shareRoomKey(room, [new UserId("@example:localhost")], new EncryptionSettings());
+            const other_user_id = new UserId("@example:localhost");
+
+            const requests = await m.shareRoomKey(room, [other_user_id.clone()], new EncryptionSettings());
 
             expect(requests).toHaveLength(1);
             expect(requests[0]).toBeInstanceOf(ToDeviceRequest);
@@ -523,7 +525,7 @@ describe(OlmMachine.name, () => {
 
             await m.markRequestAsSent(requests[0].id, RequestType.ToDevice, "{}");
 
-            const requestsAfterMarkedAsSent = await m.shareRoomKey(room, [new UserId("@example:localhost")], new EncryptionSettings());
+            const requestsAfterMarkedAsSent = await m.shareRoomKey(room, [other_user_id.clone()], new EncryptionSettings());
             expect(requestsAfterMarkedAsSent).toHaveLength(0);
         });