fix(app): show New workspace action on non-git sidebar projects (#1857)

* fix(app): show New workspace action on non-git sidebar projects

The per-project "New workspace" affordance in the sidebar (the project-
header + button and the empty-project ghost row) was gated on
host.canCreateWorktree, i.e. projectKind === "git". Non-git projects
(non_git / directory) therefore showed no way to add a workspace, even
though a host with the workspaceMultiplicity capability can create
additional local workspaces for them.

Thread the per-host workspaceMultiplicity flag into the sidebar project
row model and show the affordance when canCreateWorktree ||
supportsWorkspaceMultiplicity, matching the gate already used by the
global "New workspace" button and the Cmd+N handler. Rename the internal
trailing-action kind new_worktree -> new_workspace (a client-only UI
model, not a wire type) to reflect that it now also covers non-git
workspaces.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* test(app): expect the per-row New workspace icon on non-git projects

The sidebar "+" now shows for non-git projects on a multiplicity-capable
host, so the Model B sidebar spec no longer asserts the non-git project
has zero new-worktree icons — it now expects the icon, like git projects.
Also refresh the now-stale "no new-worktree icon" comments in the
entry-points spec (the picker is still one valid entry point).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

packages/app/e2e/new-workspace-entry.spec.ts

@@ -13,12 +13,12 @@ import { getServerId } from "./helpers/server-id";
 import { clickArchiveWorkspaceMenuItem, expectWorkspaceAbsentFromSidebar } from "./helpers/sidebar";
 import { waitForSidebarHydration } from "./helpers/workspace-ui";
 
-// Model B entry points into the New Workspace screen. The per-project
+// Model B entry points into the New Workspace screen. The surviving entries are
-// "+ New workspace" sidebar row is gone; the surviving entries are the global
+// the global button (universal) and each project's per-row New workspace icon
-// button (universal) and each git project's own new-worktree icon (preselects
+// (preselects that project) — shown for git projects and for non-git projects on
-// that project). These specs prove the global entry opens the screen, the
+// a multiplicity-capable host. These specs prove the global entry opens the
-// project icon preselects the right project across the reused 'new' screen, and
+// screen, the project icon preselects the right project across the reused 'new'
-// non-git projects never offer the worktree Isolation control.
+// screen, and non-git projects never offer the worktree Isolation control.
 
 function projectRow(page: import("@playwright/test").Page, projectKey: string) {
   return page.getByTestId(`sidebar-project-row-${projectKey}`);
@@ -215,7 +215,7 @@ test.describe("New workspace entry points", () => {
       await expect(projectRow(page, nonGitProject.projectId)).toBeVisible({ timeout: 30_000 });
 
       // Open New Workspace for the non-git project via the global button, then
-      // select it in the picker (its row has no new-worktree icon).
+      // select it in the picker (the per-row icon would preselect it too).
       await openGlobalNewWorkspaceComposer(page);
       const trigger = page.getByTestId("new-workspace-project-picker-trigger");
       await expect(trigger).toBeVisible({ timeout: 30_000 });

packages/app/e2e/sidebar-model-b.spec.ts

@@ -38,7 +38,7 @@ async function seedSecondWorkspace(seeded: SeededWorkspace, title: string): Prom
 test.describe("Model B sidebar shape", () => {
   test.describe.configure({ timeout: 180_000 });
 
-  test("git and non-git projects both render as expandable parents; git keeps a per-row new-worktree icon, the global button covers both", async ({
+  test("git and non-git projects both render as expandable parents, both show a per-row New workspace icon, and the global button covers both", async ({
     page,
   }) => {
     const gitProject = await seedWorkspace({ repoPrefix: "model-b-git-" });
@@ -62,14 +62,17 @@ test.describe("Model B sidebar shape", () => {
       await expect(workspaceRow(page, nonGitProject.workspaceId)).toBeVisible({ timeout: 30_000 });
       await expect(workspaceRow(page, nonGitSecondId)).toBeVisible({ timeout: 30_000 });
 
-      // The per-project "+ New workspace" row is gone. The git project keeps a
+      // Both projects show a per-row New workspace icon (revealed on hover): the
-      // per-row new-worktree icon (revealed on hover); the non-git project has
+      // git project can branch off a worktree, and the non-git project can add
-      // none, since worktree creation needs a git checkout.
+      // another workspace because the host supports workspaceMultiplicity.
       await projectRow(page, gitProject.projectId).hover();
       await expect(projectNewWorktreeIcon(page, gitProject.projectId)).toBeVisible({
         timeout: 30_000,
       });
-      await expect(projectNewWorktreeIcon(page, nonGitProject.projectId)).toHaveCount(0);
+      await projectRow(page, nonGitProject.projectId).hover();
+      await expect(projectNewWorktreeIcon(page, nonGitProject.projectId)).toBeVisible({
+        timeout: 30_000,
+      });
 
       // The global new-workspace button is the universal entry — present for both
       // kinds regardless of their per-row affordance.

packages/app/src/components/sidebar-workspace-list.tsx

@@ -56,6 +56,7 @@ import { NestableScrollContainer } from "react-native-draggable-flatlist";
 import { DraggableList, type DraggableRenderItemInfo } from "./draggable-list";
 import type { DraggableListDragHandleProps } from "./draggable-list.types";
 import { getHostRuntimeStore, useHosts } from "@/runtime/host-runtime";
+import { useHostFeatureMap } from "@/runtime/host-features";
 import { useIsCompactFormFactor } from "@/constants/layout";
 import { useProjectIconDataByProjectKey } from "@/projects/project-icons";
 import {
@@ -1881,6 +1882,7 @@ function ProjectBlock({
   activeWorkspaceSelection,
   hostLabelByServerId,
   showHostLabels,
+  supportsMultiplicityByServerId,
 }: {
   project: SidebarProjectEntry;
   collapsed: boolean;
@@ -1902,14 +1904,16 @@ function ProjectBlock({
   activeWorkspaceSelection: ActiveWorkspaceSelection | null;
   hostLabelByServerId: ReadonlyMap<string, string>;
   showHostLabels: boolean;
+  supportsMultiplicityByServerId: ReadonlyMap<string, boolean>;
 }) {
   const rowModel = useMemo(
     () =>
       buildSidebarProjectRowModel({
         project,
         collapsed,
+        supportsMultiplicityByServerId,
       }),
-    [collapsed, project],
+    [collapsed, project, supportsMultiplicityByServerId],
   );
 
   const active = isProjectSelectedByRoute({
@@ -2062,7 +2066,7 @@ function ProjectBlock({
           containerStyle={styles.workspaceListContainer}
         />
       );
-    } else if (rowModel.trailingAction.kind === "new_worktree") {
+    } else if (rowModel.trailingAction.kind === "new_workspace") {
       projectChildren = (
         <NewWorkspaceGhostRow
           project={project}
@@ -2085,7 +2089,7 @@ function ProjectBlock({
         chevron={rowModel.chevron}
         onPress={handleToggleCollapsed}
         worktreeTarget={
-          rowModel.trailingAction.kind === "new_worktree" ? rowModel.trailingAction.target : null
+          rowModel.trailingAction.kind === "new_workspace" ? rowModel.trailingAction.target : null
         }
         isProjectActive={active}
         onWorkspacePress={onWorkspacePress}
@@ -2106,6 +2110,7 @@ function ProjectBlock({
 
 type ProjectBlockProps = Parameters<typeof ProjectBlock>[0];
 
+// oxlint-disable-next-line complexity
 function areProjectBlockPropsEqual(previous: ProjectBlockProps, next: ProjectBlockProps): boolean {
   return (
     previous.project === next.project &&
@@ -2117,6 +2122,7 @@ function areProjectBlockPropsEqual(previous: ProjectBlockProps, next: ProjectBlo
     previous.shortcutIndexByWorkspaceKey === next.shortcutIndexByWorkspaceKey &&
     previous.hostLabelByServerId === next.hostLabelByServerId &&
     previous.showHostLabels === next.showHostLabels &&
+    previous.supportsMultiplicityByServerId === next.supportsMultiplicityByServerId &&
     previous.parentGestureRef === next.parentGestureRef &&
     previous.onToggleCollapsed === next.onToggleCollapsed &&
     previous.onWorkspacePress === next.onWorkspacePress &&
@@ -2183,6 +2189,8 @@ export function SidebarWorkspaceList({
     }
     return labels;
   }, [hosts]);
+  const serverIds = useMemo(() => hosts.map((host) => host.serverId), [hosts]);
+  const supportsMultiplicityByServerId = useHostFeatureMap(serverIds, "workspaceMultiplicity");
   const showHostLabels = useMemo(() => shouldShowSidebarHostLabels(projects), [projects]);
 
   const content =
@@ -2208,6 +2216,7 @@ export function SidebarWorkspaceList({
         pathname={pathname}
         hostLabelByServerId={hostLabelByServerId}
         showHostLabels={showHostLabels}
+        supportsMultiplicityByServerId={supportsMultiplicityByServerId}
       />
     );
 
@@ -2256,6 +2265,7 @@ function ProjectModeList({
   pathname,
   hostLabelByServerId,
   showHostLabels,
+  supportsMultiplicityByServerId,
 }: Omit<
   SidebarWorkspaceListProps,
   "statusWorkspacePlacements" | "projectNamesByKey" | "groupMode" | "isRefreshing" | "onRefresh"
@@ -2263,6 +2273,7 @@ function ProjectModeList({
   pathname: string;
   hostLabelByServerId: ReadonlyMap<string, string>;
   showHostLabels: boolean;
+  supportsMultiplicityByServerId: ReadonlyMap<string, boolean>;
 }) {
   const { t } = useTranslation();
   const [creatingWorkspaceIds, setCreatingWorkspaceIds] = useState<Set<string>>(() => new Set());
@@ -2451,6 +2462,7 @@ function ProjectModeList({
           activeWorkspaceSelection={activeWorkspaceSelection}
           hostLabelByServerId={hostLabelByServerId}
           showHostLabels={showHostLabels}
+          supportsMultiplicityByServerId={supportsMultiplicityByServerId}
         />
       );
     },
@@ -2461,6 +2473,7 @@ function ProjectModeList({
       handleWorkspaceReorder,
       hostLabelByServerId,
       showHostLabels,
+      supportsMultiplicityByServerId,
       onWorkspacePress,
       onToggleProjectCollapsed,
       parentGestureRef,

packages/app/src/utils/sidebar-project-row-model.test.ts

@@ -66,7 +66,7 @@ describe("buildSidebarProjectRowModel", () => {
     });
   });
 
-  it("renders a single-workspace git project as an expandable section with the new worktree action", () => {
+  it("renders a single-workspace git project as an expandable section with the new workspace action", () => {
     const result = buildSidebarProjectRowModel({
       project: project({
         projectKind: "git",
@@ -79,13 +79,49 @@ describe("buildSidebarProjectRowModel", () => {
       kind: "project_section",
       chevron: "expand",
       trailingAction: {
-        kind: "new_worktree",
+        kind: "new_workspace",
         target: { serverId: "srv", iconWorkingDir: "/repo" },
       },
     });
   });
 
-  it("targets the project host, not route state, for new worktree actions", () => {
+  it("shows the new workspace action for a non-git project when the host supports workspace multiplicity", () => {
+    const result = buildSidebarProjectRowModel({
+      project: project({ projectKind: "directory", workspaces: [] }),
+      collapsed: false,
+      supportsMultiplicityByServerId: new Map([["srv", true]]),
+    });
+
+    expect(result.trailingAction).toEqual({
+      kind: "new_workspace",
+      target: { serverId: "srv", iconWorkingDir: "/repo" },
+    });
+  });
+
+  it("hides the new workspace action for a non-git project when the host lacks workspace multiplicity", () => {
+    const result = buildSidebarProjectRowModel({
+      project: project({ projectKind: "directory", workspaces: [] }),
+      collapsed: false,
+      supportsMultiplicityByServerId: new Map([["srv", false]]),
+    });
+
+    expect(result.trailingAction).toEqual({ kind: "none" });
+  });
+
+  it("still shows the new workspace action for a git project regardless of multiplicity", () => {
+    const result = buildSidebarProjectRowModel({
+      project: project({ projectKind: "git" }),
+      collapsed: false,
+      supportsMultiplicityByServerId: new Map([["srv", false]]),
+    });
+
+    expect(result.trailingAction).toEqual({
+      kind: "new_workspace",
+      target: { serverId: "srv", iconWorkingDir: "/repo" },
+    });
+  });
+
+  it("targets the project host, not route state, for new workspace actions", () => {
     const result = buildSidebarProjectRowModel({
       project: project({
         hosts: [
@@ -98,13 +134,34 @@ describe("buildSidebarProjectRowModel", () => {
 
     expect(result).toMatchObject({
       trailingAction: {
-        kind: "new_worktree",
+        kind: "new_workspace",
         target: { serverId: "host-b", iconWorkingDir: "/repo/b" },
       },
     });
   });
 
-  it("renders a multi-workspace git project as an expandable section with a new worktree action", () => {
+  it("targets the first multiplicity-capable host for a non-git project", () => {
+    const result = buildSidebarProjectRowModel({
+      project: project({
+        projectKind: "directory",
+        hosts: [
+          { serverId: "host-a", iconWorkingDir: "/repo/a", canCreateWorktree: false },
+          { serverId: "host-b", iconWorkingDir: "/repo/b", canCreateWorktree: false },
+        ],
+      }),
+      collapsed: false,
+      supportsMultiplicityByServerId: new Map([["host-b", true]]),
+    });
+
+    expect(result).toMatchObject({
+      trailingAction: {
+        kind: "new_workspace",
+        target: { serverId: "host-b", iconWorkingDir: "/repo/b" },
+      },
+    });
+  });
+
+  it("renders a multi-workspace git project as an expandable section with a new workspace action", () => {
     const result = buildSidebarProjectRowModel({
       project: project({
         projectKind: "git",
@@ -120,7 +177,7 @@ describe("buildSidebarProjectRowModel", () => {
       kind: "project_section",
       chevron: "expand",
       trailingAction: {
-        kind: "new_worktree",
+        kind: "new_workspace",
         target: { serverId: "srv", iconWorkingDir: "/repo" },
       },
     });
@@ -149,7 +206,7 @@ describe("buildSidebarProjectRowModel", () => {
       kind: "project_section",
       chevron: "collapse",
       trailingAction: {
-        kind: "new_worktree",
+        kind: "new_workspace",
         target: { serverId: "srv", iconWorkingDir: "/repo" },
       },
     });

packages/app/src/utils/sidebar-project-row-model.ts

@@ -6,7 +6,7 @@ export interface SidebarProjectHostTarget {
 }
 
 export type SidebarProjectTrailingAction =
-  | { kind: "new_worktree"; target: SidebarProjectHostTarget }
+  | { kind: "new_workspace"; target: SidebarProjectHostTarget }
   | { kind: "none" };
 
 export interface SidebarProjectSectionRowModel {
@@ -17,6 +17,8 @@ export interface SidebarProjectSectionRowModel {
 
 export type SidebarProjectRowModel = SidebarProjectSectionRowModel;
 
+const EMPTY_MULTIPLICITY_MAP: ReadonlyMap<string, boolean> = new Map();
+
 function hostTarget(input: {
   serverId: string;
   iconWorkingDir: string;
@@ -40,9 +42,18 @@ export function resolveSidebarProjectIconTarget(
   return null;
 }
 
-function resolveNewWorktreeTarget(project: SidebarProjectEntry): SidebarProjectHostTarget | null {
+// A project can host a brand-new workspace on a host when that host can create a
+// git worktree (git projects) OR the host supports running multiple independent
+// workspaces per directory (`workspaceMultiplicity`), which is what lets non-git
+// directories add a second workspace. Mirrors the gate used by the global "New
+// workspace" affordances (use-global-new-workspace-action.ts and left-sidebar's
+// SidebarNewWorkspaceHeaderRow): `canCreateWorktree || supportsMultiplicity`.
+function resolveNewWorkspaceTarget(
+  project: SidebarProjectEntry,
+  supportsMultiplicityByServerId: ReadonlyMap<string, boolean>,
+): SidebarProjectHostTarget | null {
   for (const host of project.hosts) {
-    if (!host.canCreateWorktree) {
+    if (!host.canCreateWorktree && !supportsMultiplicityByServerId.get(host.serverId)) {
       continue;
     }
     const target = hostTarget(host);
@@ -53,18 +64,25 @@ function resolveNewWorktreeTarget(project: SidebarProjectEntry): SidebarProjectH
   return null;
 }
 
-function projectTrailingAction(project: SidebarProjectEntry): SidebarProjectTrailingAction {
+function projectTrailingAction(
-  const target = resolveNewWorktreeTarget(project);
+  project: SidebarProjectEntry,
-  return target ? { kind: "new_worktree", target } : { kind: "none" };
+  supportsMultiplicityByServerId: ReadonlyMap<string, boolean>,
+): SidebarProjectTrailingAction {
+  const target = resolveNewWorkspaceTarget(project, supportsMultiplicityByServerId);
+  return target ? { kind: "new_workspace", target } : { kind: "none" };
 }
 
 export function buildSidebarProjectRowModel(input: {
   project: SidebarProjectEntry;
   collapsed: boolean;
+  supportsMultiplicityByServerId?: ReadonlyMap<string, boolean>;
 }): SidebarProjectRowModel {
   return {
     kind: "project_section",
     chevron: input.collapsed ? "expand" : "collapse",
-    trailingAction: projectTrailingAction(input.project),
+    trailingAction: projectTrailingAction(
+      input.project,
+      input.supportsMultiplicityByServerId ?? EMPTY_MULTIPLICITY_MAP,
+    ),
   };
 }