feat(plugin): decompose tab controls (#48129)

Co-authored-by: vimtor <36263538+vimtor@users.noreply.github.com>
Co-authored-by: Victor Navarro <vn4varro@gmail.com>

Author: opencode-agent[bot]

packages/plugin/src/tui/context.ts

@@ -487,10 +487,12 @@ export interface UI {
       readonly attention: boolean
       readonly unread?: "activity" | "error"
     }[]
-    /** Opens (or focuses) a tab for a session, adding it when not already open. Returns false when tabs are disabled. */
+    /** Opens a tab for a session without focusing it. Returns false when tabs are disabled. */
     open(sessionID: string): boolean
-    /** Focuses an already-open tab and returns false when it is not open. */
+    /** Opens a tab when needed, then focuses it. Returns false when tabs are disabled. */
     focus(sessionID: string): boolean
+    /** Moves an open tab to an index and returns false when it is not open. */
+    move(sessionID: string, index: number): boolean
     /** Closes an open tab, or the active tab when omitted, and returns false when no tab matched. */
     close(sessionID?: string): boolean
   }

packages/tui/src/context/session-tabs.tsx

@@ -395,6 +395,15 @@ export const { use: useSessionTabs, provider: SessionTabsProvider } = createSimp
         if (!enabled()) return
         route.navigate({ type: "session", sessionID: root(sessionID) })
       },
+      open(sessionID: string) {
+        if (!enabled()) return
+        const session = root(sessionID)
+        if (state().tabs.some((tab) => tab.sessionID === session)) return
+        cancelledTabs.delete(session)
+        update((draft) => {
+          draft.tabs = openSessionTab(draft.tabs, { sessionID: session, title: title(session) })
+        })
+      },
       promote(sessionID: string) {
         if (!enabled()) return
         const session = root(sessionID)

packages/tui/src/plugin/api.tsx

@@ -206,15 +206,21 @@ export function createPluginContext(input: {
           }),
         open(sessionID) {
           if (!host.sessionTabs.enabled()) return false
-          host.sessionTabs.select(sessionID)
+          host.sessionTabs.open(sessionID)
           return true
         },
         focus(sessionID) {
           if (!host.sessionTabs.enabled()) return false
-          if (!host.sessionTabs.tabs().some((tab) => tab.sessionID === sessionID)) return false
           host.sessionTabs.select(sessionID)
           return true
         },
+        move(sessionID, index) {
+          if (!host.sessionTabs.enabled()) return false
+          const target = host.data.session.root(sessionID)
+          if (!host.sessionTabs.tabs().some((tab) => tab.sessionID === target)) return false
+          host.sessionTabs.move(target, index)
+          return true
+        },
         close(sessionID) {
           if (!host.sessionTabs.enabled()) return false
           const target = sessionID ?? host.sessionTabs.current()

packages/tui/test/context/session-tabs.test.tsx

@@ -265,6 +265,23 @@ test("loads VCS metadata for each persisted tab location", async () => {
   }
 })
 
+test("opens a background tab without changing the current session", async () => {
+  const setup = await renderSessionTabs("first")
+
+  try {
+    await wait(() => setup.tabs.current() === "first" && setup.tabs.tabs().some((tab) => tab.sessionID === "first"))
+    setup.tabs.open("background")
+    await wait(() => setup.tabs.tabs().some((tab) => tab.sessionID === "background"))
+
+    expect(setup.tabs.current()).toBe("first")
+    expect(setup.tabs.isPreview("background")).toBe(false)
+    setup.tabs.move("background", 0)
+    await wait(() => setup.tabs.tabs()[0]?.sessionID === "background")
+  } finally {
+    await setup.destroy()
+  }
+})
+
 test("loads location metadata when an open session moves", async () => {
   const destination = `${directory}/moved-worktree`
   const setup = await renderSessionTabs("first")

services/www/src/docs/content/build/plugins/cli.mdx

@@ -375,13 +375,15 @@ context.ui.router.navigate({ type: "home" })
 return unregister
 ```
 
-Tabs can be listed, opened, focused, and closed when session tabs are enabled.
+Tabs can be listed, opened, focused, moved, and closed when session tabs are enabled. `open` leaves focus unchanged;
+`focus` opens the tab when needed.
 
 ```ts
 if (context.ui.tabs.enabled()) {
-  context.ui.tabs.open(sessionID)
-  const tabs = context.ui.tabs.list()
+  context.ui.tabs.open(backgroundSessionID)
   context.ui.tabs.focus(sessionID)
+  const tabs = context.ui.tabs.list()
+  context.ui.tabs.move(backgroundSessionID, tabs.length - 1)
   context.ui.tabs.close(sessionID)
   context.ui.tabs.close()
 }