feat(desktop): reopen closed tabs and background tab open (#35010)

Co-authored-by: LukeParkerDev <10430890+Hona@users.noreply.github.com>

packages/app/src/context/tabs.test.ts

@@ -1,6 +1,21 @@
 import { describe, expect, test } from "bun:test"
 import { createRoot, getOwner, onCleanup } from "solid-js"
 import { createTabMemory } from "./tab-memory"
+import {
+  nextTabAfterClose,
+  pushClosedTab,
+  removeClosedTabs,
+  takeClosedTab,
+  type ClosedTab,
+} from "./closed-tabs"
+import type { SessionTab, Tab } from "./tabs"
+import type { ServerConnection } from "./server"
+
+const server = "local\nhttp://localhost:4096" as ServerConnection.Key
+
+function sessionTab(sessionId: string): SessionTab {
+  return { type: "session", server, sessionId }
+}
 
 describe("tab memory", () => {
   test("keeps state until its tab is removed", () => {
@@ -22,3 +37,75 @@ describe("tab memory", () => {
     })
   })
 })
+
+describe("closed tab stack", () => {
+  test("records session tabs with their index", () => {
+    const stack = pushClosedTab([], sessionTab("a"), 2)
+
+    expect(stack).toEqual([{ tab: sessionTab("a"), index: 2 }])
+  })
+
+  test("ignores draft tabs", () => {
+    const draft: Tab = { type: "draft", draftID: "d1", server, directory: "/tmp" }
+
+    expect(pushClosedTab([], draft, 0)).toEqual([])
+  })
+
+  test("caps the stack size", () => {
+    const stack = Array.from({ length: 30 }, (_, i) => i).reduce<ClosedTab[]>(
+      (acc, i) => pushClosedTab(acc, sessionTab(`s${i}`), i),
+      [],
+    )
+
+    expect(stack).toHaveLength(25)
+    expect(stack[0]?.tab.sessionId).toBe("s5")
+    expect(stack.at(-1)?.tab.sessionId).toBe("s29")
+  })
+
+  test("pops the most recently closed tab", () => {
+    const stack = [
+      { tab: sessionTab("a"), index: 0 },
+      { tab: sessionTab("b"), index: 1 },
+    ]
+    const result = takeClosedTab(stack, [])
+
+    expect(result.entry?.tab.sessionId).toBe("b")
+    expect(result.stack).toEqual([{ tab: sessionTab("a"), index: 0 }])
+  })
+
+  test("skips entries whose tab is already open", () => {
+    const stack = [
+      { tab: sessionTab("a"), index: 0 },
+      { tab: sessionTab("b"), index: 1 },
+    ]
+    const result = takeClosedTab(stack, [sessionTab("b")])
+
+    expect(result.entry?.tab.sessionId).toBe("a")
+    expect(result.stack).toEqual([])
+  })
+
+  test("returns no entry when everything is open or empty", () => {
+    expect(takeClosedTab([], []).entry).toBeUndefined()
+
+    const result = takeClosedTab([{ tab: sessionTab("a"), index: 0 }], [sessionTab("a")])
+    expect(result.entry).toBeUndefined()
+    expect(result.stack).toEqual([])
+  })
+
+  test("purges removed sessions", () => {
+    const stack = [
+      { tab: sessionTab("a"), index: 0 },
+      { tab: sessionTab("b"), index: 1 },
+    ]
+
+    expect(removeClosedTabs(stack, server, ["a"])).toEqual([{ tab: sessionTab("b"), index: 1 }])
+  })
+
+  test("does not navigate when a background tab closes", () => {
+    const tabs = [sessionTab("a"), sessionTab("b"), sessionTab("c")]
+
+    expect(nextTabAfterClose(tabs, 1, false)).toBeUndefined()
+    expect(nextTabAfterClose(tabs, 1, true)).toEqual(sessionTab("c"))
+    expect(nextTabAfterClose([sessionTab("a")], 0, true)).toBeNull()
+  })
+})