Fix waiter key collisions across plugins (#6)

Author: benvinegar

opencode/glance.test.ts

@@ -54,6 +54,12 @@ function cleanupWaiters() {
   }
 }
 
+function getOpenCodeWaiterKeys(): string[] {
+  return Object.keys(globalThis).filter((key) =>
+    key.startsWith("__glance_waiter_opencode_"),
+  )
+}
+
 /**
  * URL-aware fetch mock. Routes by URL so both the background loop and
  * tool calls get correct responses regardless of call order.
@@ -216,6 +222,39 @@ describe("opencode glance plugin", () => {
       expect(result).toContain("https://glance.sh/chunked.png")
     })
 
+    it("registers distinct waiters even within the same millisecond", async () => {
+      vi.stubGlobal(
+        "fetch",
+        routedFetch({
+          session: { id: "sess-waiters", url: "/s/sess-waiters" },
+        }),
+      )
+
+      const GlancePlugin = await loadPlugin()
+      const plugin = await GlancePlugin(mockClient())
+
+      await plugin.tool.glance.execute({})
+
+      const dateNowSpy = vi.spyOn(Date, "now").mockReturnValue(123)
+      const ac1 = new AbortController()
+      const ac2 = new AbortController()
+
+      const wait1 = plugin.tool.glance_wait.execute({}, mockContext(ac1.signal))
+      const wait2 = plugin.tool.glance_wait.execute({}, mockContext(ac2.signal))
+
+      expect(getOpenCodeWaiterKeys()).toHaveLength(2)
+
+      ac1.abort()
+      ac2.abort()
+
+      await expect(Promise.all([wait1, wait2])).resolves.toEqual([
+        "Session timed out. Ask the user to paste an image at https://glance.sh/s/sess-waiters",
+        "Session timed out. Ask the user to paste an image at https://glance.sh/s/sess-waiters",
+      ])
+
+      dateNowSpy.mockRestore()
+    })
+
     it("returns timeout message when aborted", async () => {
       vi.stubGlobal(
         "fetch",

opencode/glance.ts

@@ -27,6 +27,8 @@ const RECONNECT_DELAY_MS = 3_000
 /** How often to create a fresh session (sessions have 10-min TTL). */
 const SESSION_REFRESH_MS = 8 * 60 * 1000
 
+const WAITER_PREFIX = "__glance_waiter_opencode_"
+
 interface SessionResponse {
   id: string
   url: string
@@ -43,6 +45,7 @@ let currentSession: SessionResponse | null = null
 let sessionCreatedAt = 0
 let abortController: AbortController | null = null
 let running = false
+let waiterCounter = 0
 
 async function createSession(): Promise<SessionResponse> {
   const res = await fetch(`${BASE_URL}/api/session`, { method: "POST" })
@@ -101,6 +104,11 @@ function sleep(ms: number): Promise<void> {
   return new Promise((r) => setTimeout(r, ms))
 }
 
+function nextWaiterKey(): string {
+  waiterCounter += 1
+  return `${WAITER_PREFIX}${Date.now()}_${waiterCounter}`
+}
+
 // ── SSE listener (multi-image) ─────────────────────────────────────
 
 async function listenForImages(
@@ -183,7 +191,7 @@ function waitForNextImage(signal?: AbortSignal): Promise<ImageEvent | null> {
 
     const timeout = setTimeout(() => resolve(null), SSE_TIMEOUT_MS)
 
-    const key = `__glance_waiter_${Date.now()}`
+    const key = nextWaiterKey()
     ;(globalThis as any)[key] = (image: ImageEvent) => {
       clearTimeout(timeout)
       delete (globalThis as any)[key]
@@ -200,7 +208,7 @@ function waitForNextImage(signal?: AbortSignal): Promise<ImageEvent | null> {
 
 function dispatchToWaiters(image: ImageEvent) {
   for (const key of Object.keys(globalThis)) {
-    if (key.startsWith("__glance_waiter_")) {
+    if (key.startsWith(WAITER_PREFIX)) {
       const fn = (globalThis as any)[key]
       if (typeof fn === "function") fn(image)
     }

pi/glance.test.ts

@@ -127,6 +127,12 @@ function createTheme(): Theme {
   };
 }
 
+function getPiWaiterKeys(): string[] {
+  return Object.keys(globalThis).filter((key) =>
+    key.startsWith("__glance_waiter_pi_"),
+  );
+}
+
 function createPi(options?: { autoShutdownOnMessage?: boolean }) {
   const events = new Map<string, (...args: any[]) => unknown>();
   const commands = new Map<string, CommandDefinition>();
@@ -293,6 +299,30 @@ describe("pi/glance", () => {
     });
   });
 
+  it("registers distinct waiters even within the same millisecond", async () => {
+    __testing.setSession({
+      id: "session-waiters",
+      url: "https://glance.sh/s/session-waiters",
+    });
+
+    const dateNowSpy = vi.spyOn(Date, "now").mockReturnValue(123);
+
+    const ac1 = new AbortController();
+    const ac2 = new AbortController();
+
+    const wait1 = __testing.waitForNextImage(ac1.signal);
+    const wait2 = __testing.waitForNextImage(ac2.signal);
+
+    expect(getPiWaiterKeys()).toHaveLength(2);
+
+    ac1.abort();
+    ac2.abort();
+
+    await expect(Promise.all([wait1, wait2])).resolves.toEqual([null, null]);
+
+    dateNowSpy.mockRestore();
+  });
+
   it("shows the active session URL through the /glance command", async () => {
     const session = {
       id: "session-4",

pi/glance.ts

@@ -29,6 +29,8 @@ const RECONNECT_DELAY_MS = 3_000;
 /** How often to create a fresh session (sessions have 10-min TTL). */
 const SESSION_REFRESH_MS = 8 * 60 * 1000; // 8 minutes — well before expiry
 
+const WAITER_PREFIX = "__glance_waiter_pi_";
+
 interface SessionResponse {
   id: string;
   url: string;
@@ -56,6 +58,7 @@ let currentSession: SessionResponse | null = null;
 let sessionCreatedAt = 0;
 let abortController: AbortController | null = null;
 let running = false;
+let waiterCounter = 0;
 
 async function createSession(): Promise<SessionResponse> {
   const res = await fetch(`${BASE_URL}/api/session`, { method: "POST" });
@@ -128,6 +131,11 @@ function sleep(ms: number): Promise<void> {
   return new Promise((r) => setTimeout(r, ms));
 }
 
+function nextWaiterKey(): string {
+  waiterCounter += 1;
+  return `${WAITER_PREFIX}${Date.now()}_${waiterCounter}`;
+}
+
 // ── SSE listener (multi-image) ─────────────────────────────────────
 
 /**
@@ -222,7 +230,7 @@ function waitForNextImage(signal?: AbortSignal): Promise<ImageEvent | null> {
 
     // Poll: check for new images by watching the background loop.
     // We do this by subscribing to a one-time callback.
-    const key = `__glance_waiter_${Date.now()}`;
+    const key = nextWaiterKey();
     (globalThis as any)[key] = (image: ImageEvent) => {
       clearTimeout(timeout);
       delete (globalThis as any)[key];
@@ -239,7 +247,7 @@ function waitForNextImage(signal?: AbortSignal): Promise<ImageEvent | null> {
 
 function getWaiterKeys(): string[] {
   return Object.keys(globalThis).filter((key) =>
-    key.startsWith("__glance_waiter_"),
+    key.startsWith(WAITER_PREFIX),
   );
 }
 
@@ -274,6 +282,7 @@ export const __testing = {
     stopBackground();
     sessionCreatedAt = 0;
     running = false;
+    waiterCounter = 0;
     clearWaiters();
   },
   setSession(session: SessionResponse | null, createdAt = Date.now()) {