refactor mpv reconnect scheduling into transport layer

src/core/services/mpv-service.ts

@@ -14,7 +14,9 @@ import {
   splitMpvMessagesFromBuffer,
 } from "./mpv-protocol";
 import { requestMpvInitialState, subscribeToMpvProperties } from "./mpv-properties";
-import { getMpvReconnectDelay } from "./mpv-transport";
+import {
+  scheduleMpvReconnect,
+} from "./mpv-transport";
 
 export {
   MPV_REQUEST_ID_SECONDARY_SUB_VISIBILITY,
@@ -192,20 +194,20 @@ export class MpvIpcClient implements MpvClient {
   }
 
   private scheduleReconnect(): void {
-    const reconnectTimer = this.deps.getReconnectTimer();
-    if (reconnectTimer) {
-      clearTimeout(reconnectTimer);
-    }
-    const attempt = this.reconnectAttempt++;
-    const delay = getMpvReconnectDelay(attempt, this.hasConnectedOnce);
-    this.deps.setReconnectTimer(
-      setTimeout(() => {
+    this.reconnectAttempt = scheduleMpvReconnect({
+      attempt: this.reconnectAttempt,
+      hasConnectedOnce: this.hasConnectedOnce,
+      getReconnectTimer: () => this.deps.getReconnectTimer(),
+      setReconnectTimer: (timer) => this.deps.setReconnectTimer(timer),
+      onReconnectAttempt: (attempt, delay) => {
         console.log(
-          `Attempting to reconnect to MPV (attempt ${attempt + 1}, delay ${delay}ms)...`,
+          `Attempting to reconnect to MPV (attempt ${attempt}, delay ${delay}ms)...`,
         );
+      },
+      connect: () => {
         this.connect();
-      }, delay),
-    );
+      },
+    });
   }
 
   private processBuffer(): void {

src/core/services/mpv-transport.test.ts

@@ -1,6 +1,9 @@
 import test from "node:test";
 import assert from "node:assert/strict";
-import { getMpvReconnectDelay } from "./mpv-transport";
+import {
+  getMpvReconnectDelay,
+  scheduleMpvReconnect,
+} from "./mpv-transport";
 
 test("getMpvReconnectDelay follows existing reconnect ramp", () => {
   assert.equal(getMpvReconnectDelay(0, true), 1000);
@@ -14,3 +17,48 @@ test("getMpvReconnectDelay follows existing reconnect ramp", () => {
   assert.equal(getMpvReconnectDelay(4, false), 1000);
   assert.equal(getMpvReconnectDelay(6, false), 2000);
 });
+
+test("scheduleMpvReconnect clears existing timer and increments attempt", () => {
+  const existing = {} as ReturnType<typeof setTimeout>;
+  const cleared: Array<ReturnType<typeof setTimeout> | null> = [];
+  const setTimers: Array<ReturnType<typeof setTimeout> | null> = [];
+  const calls: Array<{ attempt: number; delay: number }> = [];
+  let connected = 0;
+
+  const originalSetTimeout = globalThis.setTimeout;
+  const originalClearTimeout = globalThis.clearTimeout;
+  (globalThis as any).setTimeout = (handler: () => void, _delay: number) => {
+    handler();
+    return 1 as unknown as ReturnType<typeof setTimeout>;
+  };
+  (globalThis as any).clearTimeout = (timer: ReturnType<typeof setTimeout> | null) => {
+    cleared.push(timer);
+  };
+
+  const nextAttempt = scheduleMpvReconnect({
+    attempt: 3,
+    hasConnectedOnce: true,
+    getReconnectTimer: () => existing,
+    setReconnectTimer: (timer) => {
+      setTimers.push(timer);
+    },
+    onReconnectAttempt: (attempt, delay) => {
+      calls.push({ attempt, delay });
+    },
+    connect: () => {
+      connected += 1;
+    },
+  });
+
+  (globalThis as any).setTimeout = originalSetTimeout;
+  (globalThis as any).clearTimeout = originalClearTimeout;
+
+  assert.equal(nextAttempt, 4);
+  assert.equal(cleared.length, 1);
+  assert.equal(cleared[0], existing);
+  assert.equal(setTimers.length, 1);
+  assert.equal(calls.length, 1);
+  assert.equal(calls[0].attempt, 4);
+  assert.equal(calls[0].delay, getMpvReconnectDelay(3, true));
+  assert.equal(connected, 1);
+});

src/core/services/mpv-transport.ts

@@ -26,3 +26,29 @@ export function getMpvReconnectDelay(
   }
   return 2000;
 }
+
+export interface MpvReconnectSchedulerDeps {
+  attempt: number;
+  hasConnectedOnce: boolean;
+  getReconnectTimer: () => ReturnType<typeof setTimeout> | null;
+  setReconnectTimer: (timer: ReturnType<typeof setTimeout> | null) => void;
+  onReconnectAttempt: (attempt: number, delay: number) => void;
+  connect: () => void;
+}
+
+export function scheduleMpvReconnect(
+  deps: MpvReconnectSchedulerDeps,
+): number {
+  const reconnectTimer = deps.getReconnectTimer();
+  if (reconnectTimer) {
+    clearTimeout(reconnectTimer);
+  }
+  const delay = getMpvReconnectDelay(deps.attempt, deps.hasConnectedOnce);
+  deps.setReconnectTimer(
+    setTimeout(() => {
+      deps.onReconnectAttempt(deps.attempt + 1, delay);
+      deps.connect();
+    }, delay),
+  );
+  return deps.attempt + 1;
+}