test(e2e): make the warning-dedup sequence independent of the catch-up race

The shared SSE connection writes its catch-up sync once — a sibling
bundle still evaluating when it arrives misses it, so a warning carried
by that sync reached the console on some runs and not others. The
widget now starts clean (an empty catch-up cannot vary the sequence)
and picks its warning up through a build the page observes.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: bjohansebas

test/e2e/__snapshots__/multi-compiler.test.js.snap.webpack5

@@ -3,9 +3,16 @@
 exports[`multi-compiler (browser) logs per-bundle lifecycles and deduplicates warning re-logs on sibling builds 1`] = `
 [
   "[webpack-dev-middleware] connected",
+  "[webpack-dev-middleware] bundle 'widget' rebuilding (<fixture> changed)",
+  "[webpack-dev-middleware] bundle 'widget' rebuilding (<fixture> changed)",
+  "[webpack-dev-middleware] bundle 'widget' rebuilt in Xms",
+  "[webpack-dev-middleware] bundle 'widget' rebuilt in Xms",
   "[webpack-dev-middleware] bundle 'widget' has 1 warnings",
   "[webpack-dev-middleware] ./entry.js 11:8-20
 Critical dependency: the request of a dependency is an expression",
+  "[webpack-dev-middleware] Checking for updates on the server...",
+  "[webpack-dev-middleware] Hot updated 2 modules.",
+  "[webpack-dev-middleware] App is up to date.",
   "[webpack-dev-middleware] bundle 'app' rebuilding (<fixture> changed)",
   "[webpack-dev-middleware] bundle 'app' rebuilding (<fixture> changed)",
   "[webpack-dev-middleware] bundle 'app' rebuilt in Xms",

test/e2e/multi-compiler.test.js

@@ -121,10 +121,14 @@ describe("multi-compiler (browser)", () => {
       }
     `;
 
+    // The widget starts clean so the connect-time catch-up sync carries no
+    // problems — whether a still-evaluating bundle misses it (the shared
+    // connection writes it once) then cannot change the sequence. The
+    // warning enters through a build the page observes.
     app = await createHotApp({
       apps: [
         { name: "app", code: bundleApp("app", "app-v1") },
-        { name: "widget", code: widgetWithWarning("widget-v1") },
+        { name: "widget", code: bundleApp("widget", "widget-v1") },
       ],
     });
     ({ page, browser } = await runBrowser());
@@ -133,20 +137,25 @@ describe("multi-compiler (browser)", () => {
     await page.goto(app.url);
     await waitForText(page, "out-app", "app-v1");
     await waitForText(page, "out-widget", "widget-v1");
-    // The widget's warning arrives with the connect-time sync, logged once.
+    await console_.waitFor("connected");
+
+    // The widget picks up the warning: logged once with its build.
+    app.edit("widget", widgetWithWarning("widget-v1b"));
+    await waitForText(page, "out-widget", "widget-v1b");
     await console_.waitFor("Critical dependency");
+    await console_.waitFor("App is up to date");
 
     // A sibling's clean rebuild must NOT re-log the widget's unchanged
     // warning (the console cache is per bundle).
     app.edit("app", bundleApp("app", "app-v2"));
     await waitForText(page, "out-app", "app-v2");
-    await console_.waitFor("App is up to date");
+    await console_.waitForCount("App is up to date", 2);
 
     // The widget's own rebuild drops its cache, so the identical warning
     // text is logged again.
     app.edit("widget", widgetWithWarning("widget-v2"));
     await waitForText(page, "out-widget", "widget-v2");
-    await console_.waitForCount("App is up to date", 2);
+    await console_.waitForCount("App is up to date", 3);
 
     expect(normalizeConsole(console_.messages)).toMatchSnapshot();
   });