fix(sync): skip duplicate status events (#1152)

* fix(sync): skip duplicate status events

* test(sync): cover duplicate idle statuses

---------

Co-authored-by: Isaac Sanchez <isanchez-hawkins@arize.com>
Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>

packages/ui/src/sync/__tests__/event-reducer.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, test } from "bun:test"
-import type { Event, Part, PermissionRequest, QuestionRequest } from "@opencode-ai/sdk/v2/client"
+import type { Event, Part, PermissionRequest, QuestionRequest, SessionStatus } from "@opencode-ai/sdk/v2/client"
 import { applyDirectoryEvent } from "../event-reducer"
 import { INITIAL_STATE, type State } from "../types"
 
@@ -8,6 +8,7 @@ function state(overrides: Partial<State> = {}): State {
     ...INITIAL_STATE,
     message: {},
     part: {},
+    session_status: {},
     ...overrides,
   }
 }
@@ -87,6 +88,68 @@ describe("applyDirectoryEvent", () => {
     expect(result).toBe(true)
   })
 
+  test("skips duplicate session status events", () => {
+    const draft = state()
+    const busyStatus = { type: "busy" } as SessionStatus
+    const event = {
+      type: "session.status",
+      properties: { sessionID: "ses_1", status: busyStatus },
+    } as Event
+
+    expect(applyDirectoryEvent(draft, event)).toBe(true)
+    const statusRef = draft.session_status.ses_1
+
+    expect(applyDirectoryEvent(draft, event)).toBe(false)
+    expect(draft.session_status.ses_1).toBe(statusRef)
+  })
+
+  test("skips duplicate session idle events", () => {
+    const draft = state()
+    const event = {
+      type: "session.idle",
+      properties: { sessionID: "ses_1" },
+    } as Event
+
+    expect(applyDirectoryEvent(draft, event)).toBe(true)
+    const statusRef = draft.session_status.ses_1
+
+    expect(applyDirectoryEvent(draft, event)).toBe(false)
+    expect(draft.session_status.ses_1).toBe(statusRef)
+  })
+
+  test("skips duplicate session error idle-state events", () => {
+    const draft = state()
+    const event = {
+      type: "session.error",
+      properties: { sessionID: "ses_1" },
+    } as Event
+
+    expect(applyDirectoryEvent(draft, event)).toBe(true)
+    const statusRef = draft.session_status.ses_1
+
+    expect(applyDirectoryEvent(draft, event)).toBe(false)
+    expect(draft.session_status.ses_1).toBe(statusRef)
+  })
+
+  test("detects retry status metadata changes", () => {
+    const draft = state({
+      session_status: {
+        ses_1: { type: "retry", attempt: 1, message: "rate limited", next: 10 } as SessionStatus,
+      },
+    })
+
+    const event = {
+      type: "session.status",
+      properties: {
+        sessionID: "ses_1",
+        status: { type: "retry", attempt: 2, message: "rate limited", next: 20 } as SessionStatus,
+      },
+    } as Event
+
+    expect(applyDirectoryEvent(draft, event)).toBe(true)
+    expect((draft.session_status.ses_1 as Extract<SessionStatus, { type: "retry" }>).attempt).toBe(2)
+  })
+
   test("updates permission request arrays immutably", () => {
     const initialPermissions = [
       { id: "perm_1", sessionID: "ses_1" } as PermissionRequest,