refactor(app): centralize session state (#33641)

packages/app/src/utils/session-placement.test.ts

@@ -1,38 +0,0 @@
-import { describe, expect, test } from "bun:test"
-import { ServerConnection } from "@/context/server"
-import { createSessionPlacementStore } from "./session-placement"
-
-describe("session placement", () => {
-  const local = ServerConnection.Key.make("http://localhost:4096")
-  const remote = ServerConnection.Key.make("https://example.com")
-
-  test("aliases a leaf and root without crossing servers", () => {
-    const store = createSessionPlacementStore()
-    store.set({ server: local, leafID: "child", rootID: "root", directory: "/repo" })
-    store.set({ server: remote, leafID: "child", rootID: "other", directory: "/remote" })
-
-    expect(store.get(local, "child")).toEqual({ rootID: "root", directory: "/repo" })
-    expect(store.get(local, "root")).toEqual({ rootID: "root", directory: "/repo" })
-    expect(store.get(remote, "child")).toEqual({ rootID: "other", directory: "/remote" })
-  })
-
-  test("inherits known placement for in-app child navigation", () => {
-    const store = createSessionPlacementStore()
-    store.set({ server: local, leafID: "parent", rootID: "root", directory: "/repo" })
-
-    expect(store.inherit(local, "parent", "child")).toEqual({ rootID: "root", directory: "/repo" })
-    expect(store.get(local, "child")).toEqual({ rootID: "root", directory: "/repo" })
-    expect(store.inherit(local, "missing", "unknown")).toBeUndefined()
-  })
-
-  test("bounds retained placement aliases", () => {
-    const store = createSessionPlacementStore()
-    for (let index = 0; index < 300; index++) {
-      store.set({ server: local, leafID: `leaf-${index}`, rootID: `root-${index}`, directory: `/repo/${index}` })
-    }
-
-    expect(store.size()).toBeLessThanOrEqual(256)
-    expect(store.get(local, "leaf-0")).toBeUndefined()
-    expect(store.get(local, "leaf-299")).toEqual({ rootID: "root-299", directory: "/repo/299" })
-  })
-})

packages/app/src/utils/session-placement.ts

@@ -1,41 +0,0 @@
-import { ServerConnection } from "@/context/server"
-
-export type SessionPlacement = {
-  rootID: string
-  directory: string
-}
-
-export function createSessionPlacementStore() {
-  const placements = new Map<string, SessionPlacement>()
-  const limit = 256
-  const key = (server: ServerConnection.Key, sessionID: string) => `${server}\0${sessionID}`
-  const write = (id: string, placement: SessionPlacement) => {
-    placements.delete(id)
-    placements.set(id, placement)
-    while (placements.size > limit) placements.delete(placements.keys().next().value!)
-  }
-
-  return {
-    get(server: ServerConnection.Key, sessionID: string) {
-      const id = key(server, sessionID)
-      const placement = placements.get(id)
-      if (placement) write(id, placement)
-      return placement
-    },
-    set(input: SessionPlacement & { server: ServerConnection.Key; leafID: string }) {
-      const placement = { rootID: input.rootID, directory: input.directory }
-      write(key(input.server, input.leafID), placement)
-      write(key(input.server, input.rootID), placement)
-      return placement
-    },
-    inherit(server: ServerConnection.Key, sourceID: string, leafID: string) {
-      const placement = placements.get(key(server, sourceID))
-      if (!placement) return
-      write(key(server, leafID), placement)
-      return placement
-    },
-    size() {
-      return placements.size
-    },
-  }
-}

packages/app/src/utils/session-route.test.ts

@@ -36,4 +36,13 @@ describe("session routes", () => {
       }),
     ).toBe(sessions.root)
   })
+
+  test("rejects a parent cycle", async () => {
+    const sessions: Record<string, { id: string; parentID?: string }> = {
+      child: { id: "child", parentID: "parent" },
+      parent: { id: "parent", parentID: "child" },
+    }
+
+    expect(rootSession(sessions.child, async (id) => sessions[id]!)).rejects.toThrow("Session parent cycle: child")
+  })
 })

packages/app/src/utils/session-route.ts

@@ -18,8 +18,13 @@ export function requireServerKey(segment: string | undefined) {
 
 type SessionParent = { id: string; parentID?: string }
 
-export async function rootSession(session: SessionParent, get: (sessionID: string) => Promise<SessionParent>) {
+export async function rootSession<T extends SessionParent>(session: T, get: (sessionID: string) => Promise<T>) {
+  const seen = new Set([session.id])
   let current = session
-  while (current.parentID) current = await get(current.parentID)
+  while (current.parentID) {
+    if (seen.has(current.parentID)) throw new Error(`Session parent cycle: ${current.parentID}`)
+    seen.add(current.parentID)
+    current = await get(current.parentID)
+  }
   return current
 }