fix(mobile): picking a project on two machines starts on the connected one (#25839)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

Author: t3dotgg

apps/mobile/src/features/threads/NewTaskRouteScreen.tsx

@@ -188,6 +188,11 @@ export function NewTaskRouteScreen({ route }: StaticScreenProps<NewTaskRoutePara
       ) ?? null)
     : null;
   const { connectedEnvironments } = useRemoteConnectionStatus();
+  const connectedEnvironmentIds = new Set(
+    connectedEnvironments
+      .filter((environment) => environment.connectionState === "connected")
+      .map((environment) => environment.environmentId),
+  );
   const openScratch = useAtomCommand(projectEnvironment.openScratch, {
     reportFailure: false,
   });
@@ -461,6 +466,7 @@ export function NewTaskRouteScreen({ route }: StaticScreenProps<NewTaskRoutePara
                 const selectionTarget = getProjectScopeSelectionTarget(
                   scope,
                   selectedEnvironmentId,
+                  connectedEnvironmentIds,
                 );
                 if (Platform.OS === "android") {
                   return (

apps/mobile/src/features/threads/new-task-project-selection.test.ts

@@ -4,6 +4,7 @@ import { describe, expect, it } from "vite-plus/test";
 import type { EnvironmentProject } from "@t3tools/client-runtime/state/shell";
 import type { HomeProjectScope } from "../home/homeThreadList";
 import {
+  getProjectScopeSelectionTarget,
   newTaskDestination,
   resolveDraftProjectSelection,
   resolveEnvironmentProjectMatch,
@@ -53,6 +54,26 @@ function makeScope(projects: ReadonlyArray<EnvironmentProject>): HomeProjectScop
   };
 }
 
+describe("getProjectScopeSelectionTarget", () => {
+  it("prefers a connected copy of a project that spans environments", () => {
+    const mac = makeProject("t3code", "mac");
+    const server = makeProject("t3code", "server");
+    const target = (connected: ReadonlyArray<string>, preferred: string | null = null) =>
+      getProjectScopeSelectionTarget(
+        makeScope([mac, server]),
+        preferred === null ? null : EnvironmentId.make(preferred),
+        new Set(connected.map((id) => EnvironmentId.make(id))),
+      );
+    expect(target(["server"])).toBe(server);
+    expect(target(["server"], "mac")).toBe(server);
+    expect(target(["mac", "server"], "server")).toBe(server);
+    expect(target(["mac", "server"])).toBe(mac);
+    // With nothing connected, the usual order still applies.
+    expect(target([], "server")).toBe(server);
+    expect(target([])).toBe(mac);
+  });
+});
+
 describe("resolveEnvironmentProjectMatch", () => {
   it("follows the same repository onto the target machine", () => {
     const selected = makeProject("t3code", "mac", { repositoryKey: "github.com/t3tools/t3code" });

apps/mobile/src/features/threads/new-task-project-selection.ts

@@ -10,12 +10,21 @@ type DraftProjectSelectionResolution =
   | { readonly kind: "pick" }
   | { readonly kind: "dismiss" };
 
+/**
+ * The copy of a project a new thread starts in: the preferred environment's, then the
+ * representative. A connected copy wins over a disconnected one.
+ */
 export function getProjectScopeSelectionTarget(
   scope: HomeProjectScope,
   preferredEnvironmentId: EnvironmentId | null,
+  connectedEnvironmentIds: ReadonlySet<EnvironmentId>,
 ): EnvironmentProject {
+  const rank = (project: EnvironmentProject) =>
+    project.environmentId === preferredEnvironmentId ? 0 : project === scope.representative ? 1 : 2;
+  const ordered = [...scope.projects].sort((left, right) => rank(left) - rank(right));
   return (
-    scope.projects.find((project) => project.environmentId === preferredEnvironmentId) ??
+    ordered.find((project) => connectedEnvironmentIds.has(project.environmentId)) ??
+    ordered[0] ??
     scope.representative
   );
 }

docs/user/thread-sidebar.md

@@ -13,7 +13,8 @@ an existing worktree, use **New thread in this worktree** from the branch toolba
 On mobile, **New thread** starts in the current thread's project, or else in the
 last project you opened or chose on that device. If neither is available, the
 project picker opens. Turn off **Settings → General → Use last project** to
-choose a project every time.
+choose a project every time. When you pick a project that is on more than one
+machine, the thread starts on a connected one if any is connected.
 
 When you change a new thread's project, T3 Code stays in the current environment
 if that project exists there. Otherwise it selects an environment that has it.