fix(client): persist workspace drag order

packages/client/runtime/src/client/workspaces/manager.ts

@@ -173,10 +173,19 @@ export class WorkspaceManager {
     const frameGeneration = this.orderFrameGeneration
     const previousOrder = this.itemViews().map(workspace => workspace.workspaceId)
     this.installOrder(insertIdBefore(previousOrder, workspaceId, beforeWorkspaceId))
-    const { result } = await this.api.workspace.insertBefore({
-      workspaceId,
-      ...beforeWorkspaceId === undefined ? {} : { beforeWorkspaceId },
-    })
+    let result: RpcResult<{ workspaceIds: WorkspaceId[] }>
+    try {
+      ;({ result } = await this.api.workspace.insertBefore({
+        workspaceId,
+        ...beforeWorkspaceId === undefined ? {} : { beforeWorkspaceId },
+      }))
+    } catch (error) {
+      if (requestGeneration === this.orderRequestGeneration
+        && frameGeneration === this.orderFrameGeneration) {
+        this.installOrder(previousOrder)
+      }
+      throw error
+    }
     if (result.ok && requestGeneration === this.orderRequestGeneration
       && frameGeneration === this.orderFrameGeneration) {
       this.installOrder(result.value.workspaceIds)

packages/client/runtime/tests/workspaces-service.spec.ts

@@ -107,6 +107,12 @@ describe('WorkspaceManager', () => {
     expect(manager.getSnapshot().items.map(item => item.workspaceId)).toEqual(['one', 'two', 'three'])
     await expect(rejected).resolves.toMatchObject({ ok: false })
     expect(manager.getSnapshot().items.map(item => item.workspaceId)).toEqual(['one', 'three', 'two'])
+
+    api.onWorkspaceInsertBefore = () => Promise.reject(new Error('transport down'))
+    const disconnected = manager.insertBefore(wid('three'), wid('one'))
+    expect(manager.getSnapshot().items.map(item => item.workspaceId)).toEqual(['three', 'one', 'two'])
+    await expect(disconnected).rejects.toThrow('transport down')
+    expect(manager.getSnapshot().items.map(item => item.workspaceId)).toEqual(['one', 'three', 'two'])
   })
 
   it('replays removal over an in-flight baseline and ignores duplicate or late updates', async () => {