WIP: remoting (#10085)

Release Notes:

- Added private alpha support for remote development. Please reach out to hi@zed.dev if you'd like to be part of shaping this feature.

crates/collab/src/tests/test_server.rs

@@ -1,4 +1,5 @@
 use crate::{
+    auth::split_dev_server_token,
     db::{tests::TestDb, NewUserParams, UserId},
     executor::Executor,
     rpc::{Principal, Server, ZedVersion, CLEANUP_TIMEOUT, RECONNECT_TIMEOUT},
@@ -302,6 +303,130 @@ impl TestServer {
         client
     }
 
+    pub async fn create_dev_server(
+        &self,
+        access_token: String,
+        cx: &mut TestAppContext,
+    ) -> TestClient {
+        cx.update(|cx| {
+            if cx.has_global::<SettingsStore>() {
+                panic!("Same cx used to create two test clients")
+            }
+            let settings = SettingsStore::test(cx);
+            cx.set_global(settings);
+            release_channel::init("0.0.0", cx);
+            client::init_settings(cx);
+        });
+        let (dev_server_id, _) = split_dev_server_token(&access_token).unwrap();
+
+        let clock = Arc::new(FakeSystemClock::default());
+        let http = FakeHttpClient::with_404_response();
+        let mut client = cx.update(|cx| Client::new(clock, http.clone(), cx));
+        let server = self.server.clone();
+        let db = self.app_state.db.clone();
+        let connection_killers = self.connection_killers.clone();
+        let forbid_connections = self.forbid_connections.clone();
+        Arc::get_mut(&mut client)
+            .unwrap()
+            .set_id(1)
+            .set_dev_server_token(client::DevServerToken(access_token.clone()))
+            .override_establish_connection(move |credentials, cx| {
+                assert_eq!(
+                    credentials,
+                    &Credentials::DevServer {
+                        token: client::DevServerToken(access_token.to_string())
+                    }
+                );
+
+                let server = server.clone();
+                let db = db.clone();
+                let connection_killers = connection_killers.clone();
+                let forbid_connections = forbid_connections.clone();
+                cx.spawn(move |cx| async move {
+                    if forbid_connections.load(SeqCst) {
+                        Err(EstablishConnectionError::other(anyhow!(
+                            "server is forbidding connections"
+                        )))
+                    } else {
+                        let (client_conn, server_conn, killed) =
+                            Connection::in_memory(cx.background_executor().clone());
+                        let (connection_id_tx, connection_id_rx) = oneshot::channel();
+                        let dev_server = db
+                            .get_dev_server(dev_server_id)
+                            .await
+                            .expect("retrieving dev_server failed");
+                        cx.background_executor()
+                            .spawn(server.handle_connection(
+                                server_conn,
+                                "dev-server".to_string(),
+                                Principal::DevServer(dev_server),
+                                ZedVersion(SemanticVersion::new(1, 0, 0)),
+                                Some(connection_id_tx),
+                                Executor::Deterministic(cx.background_executor().clone()),
+                            ))
+                            .detach();
+                        let connection_id = connection_id_rx.await.map_err(|e| {
+                            EstablishConnectionError::Other(anyhow!(
+                                "{} (is server shutting down?)",
+                                e
+                            ))
+                        })?;
+                        connection_killers
+                            .lock()
+                            .insert(connection_id.into(), killed);
+                        Ok(client_conn)
+                    }
+                })
+            });
+
+        let fs = FakeFs::new(cx.executor());
+        let user_store = cx.new_model(|cx| UserStore::new(client.clone(), cx));
+        let workspace_store = cx.new_model(|cx| WorkspaceStore::new(client.clone(), cx));
+        let language_registry = Arc::new(LanguageRegistry::test(cx.executor()));
+        let app_state = Arc::new(workspace::AppState {
+            client: client.clone(),
+            user_store: user_store.clone(),
+            workspace_store,
+            languages: language_registry,
+            fs: fs.clone(),
+            build_window_options: |_, _| Default::default(),
+            node_runtime: FakeNodeRuntime::new(),
+        });
+
+        cx.update(|cx| {
+            theme::init(theme::LoadThemes::JustBase, cx);
+            Project::init(&client, cx);
+            client::init(&client, cx);
+            language::init(cx);
+            editor::init(cx);
+            workspace::init(app_state.clone(), cx);
+            call::init(client.clone(), user_store.clone(), cx);
+            channel::init(&client, user_store.clone(), cx);
+            notifications::init(client.clone(), user_store, cx);
+            collab_ui::init(&app_state, cx);
+            file_finder::init(cx);
+            menu::init();
+            headless::init(
+                client.clone(),
+                headless::AppState {
+                    languages: app_state.languages.clone(),
+                    user_store: app_state.user_store.clone(),
+                    fs: fs.clone(),
+                    node_runtime: app_state.node_runtime.clone(),
+                },
+                cx,
+            );
+        });
+
+        TestClient {
+            app_state,
+            username: "dev-server".to_string(),
+            channel_store: cx.read(ChannelStore::global).clone(),
+            notification_store: cx.read(NotificationStore::global).clone(),
+            state: Default::default(),
+        }
+    }
+
     pub fn disconnect_client(&self, peer_id: PeerId) {
         self.connection_killers
             .lock()