Stop transient file conflict callouts (#2694)

* fix(app): prevent transient file conflict callouts

Watcher versions are candidates until a matching disk read settles them. The editor now classifies the settled bytes once, preserving dirty buffers and keeping reload content paired with its revision.

* fix(app): preserve external BOM changes

packages/app/e2e/helpers/daemon-websocket-gate.ts

@@ -76,6 +76,8 @@ export async function installDaemonWebSocketGate(page: Page) {
   const clientRequestCounts = new Map<string, number>();
   const subscribedFilePaths = new Set<string>();
   const fileSubscriptionWaiters = new Map<string, () => void>();
+  const observedFileUpdates = new Set<string>();
+  const fileUpdateWaiters = new Map<string, () => void>();
   let fileReadPathToHold: string | null = null;
   let heldFileReads: Array<() => void> = [];
   let resolveHeldFileRead: (() => void) | null = null;
@@ -84,6 +86,19 @@ export async function installDaemonWebSocketGate(page: Page) {
   let heldReadyFileUpdate: (() => void) | null = null;
   let resolveHeldReadyFileUpdate: (() => void) | null = null;
   let heldReadyFileUpdatePromise = Promise.resolve();
+  const recordFileUpdate = (message: ServerMessage): void => {
+    if (
+      message.type !== "fs.file.update" ||
+      typeof message.payload?.version?.status !== "string" ||
+      typeof message.payload.version.path !== "string"
+    ) {
+      return;
+    }
+    const key = `${message.payload.version.path}:${message.payload.version.status}`;
+    observedFileUpdates.add(key);
+    fileUpdateWaiters.get(key)?.();
+    fileUpdateWaiters.delete(key);
+  };
 
   await page.routeWebSocket(daemonWsRoutePattern(), (ws) => {
     if (!acceptingConnections) {
@@ -134,6 +149,7 @@ export async function installDaemonWebSocketGate(page: Page) {
         fileSubscriptionWaiters.get(path)?.();
         fileSubscriptionWaiters.delete(path);
       }
+      if (serverMessage) recordFileUpdate(serverMessage);
       if (
         serverMessage?.type === "fs.file.update" &&
         serverMessage.payload?.version?.status === "ready" &&
@@ -157,6 +173,11 @@ export async function installDaemonWebSocketGate(page: Page) {
       if (subscribedFilePaths.has(path)) return Promise.resolve();
       return new Promise((resolve) => fileSubscriptionWaiters.set(path, resolve));
     },
+    waitForFileUpdate(path: string, status: "ready" | "missing" | "error"): Promise<void> {
+      const key = `${path}:${status}`;
+      if (observedFileUpdates.has(key)) return Promise.resolve();
+      return new Promise((resolve) => fileUpdateWaiters.set(key, resolve));
+    },
     holdFileReads(path: string): void {
       fileReadPathToHold = path;
       heldFileReads = [];

packages/app/e2e/helpers/file-callouts.ts

@@ -0,0 +1,48 @@
+import type { Page } from "@playwright/test";
+import { expect } from "../fixtures";
+
+export async function recordFileCallouts(page: Page): Promise<void> {
+  await page.evaluate(() => {
+    const callouts: string[] = [];
+    const recordAlert = (alert: Element) => {
+      const text = alert.textContent?.trim();
+      if (text && !callouts.includes(text)) callouts.push(text);
+    };
+    const record = (records: MutationRecord[]) => {
+      for (const mutation of records) {
+        if (
+          !(mutation.target instanceof Element) ||
+          !mutation.target.closest('[data-testid="workspace-file-pane"]')
+        ) {
+          continue;
+        }
+        for (const node of mutation.addedNodes) {
+          if (!(node instanceof Element)) continue;
+          if (node.matches('[role="alert"]')) recordAlert(node);
+          for (const alert of node.querySelectorAll('[role="alert"]')) recordAlert(alert);
+        }
+      }
+    };
+    const observer = new MutationObserver(record);
+    observer.observe(document.body, { childList: true, subtree: true, characterData: true });
+    Object.assign(globalThis, { __PASEO_RECORDED_FILE_CALLOUTS__: callouts });
+  });
+}
+
+export async function expectFileCalloutWasRendered(page: Page, title: string): Promise<void> {
+  await expect
+    .poll(() => recordedFileCallouts(page))
+    .toEqual(expect.arrayContaining([expect.stringContaining(title)]));
+}
+
+export async function expectNoFileCalloutWasRendered(page: Page): Promise<void> {
+  await expect.poll(() => recordedFileCallouts(page)).toEqual([]);
+}
+
+function recordedFileCallouts(page: Page): Promise<string[]> {
+  return page.evaluate(
+    () =>
+      (globalThis as typeof globalThis & { __PASEO_RECORDED_FILE_CALLOUTS__?: string[] })
+        .__PASEO_RECORDED_FILE_CALLOUTS__ ?? [],
+  );
+}