test(e2e): cover the Mail chip label after a POST-redirect-GET with a seeded fixture pair.

e2e/support/environment.js

@@ -80,11 +80,17 @@ export function debugApps() {
     ? configuredURLs
     : defaults.map((app) => app.baseURL);
 
-  return urls.map((baseURL, index) => ({
-    name:
-      configuredNames?.[index] ?? defaults[index]?.name ?? `app-${index + 1}`,
-    baseURL: validatedBaseURL(baseURL, index),
-  }));
+  // `id` is the fixture-contract identity and never follows DEBUG_UI_APP_NAMES, so specs can branch on it safely;
+  // `name` is the display label used in test titles.
+  return urls.map((baseURL, index) => {
+    const id = defaults[index]?.name ?? `app-${index + 1}`;
+
+    return Object.freeze({
+      id,
+      name: configuredNames?.[index] ?? id,
+      baseURL: validatedBaseURL(baseURL, index),
+    });
+  });
 }
 
 export function fixtureTag(state = "dense") {

e2e/toolbar-mail.spec.js

@@ -0,0 +1,68 @@
+import { expect, test } from "@playwright/test";
+
+import {
+  collectRuntimeDiagnostics,
+  expandToolbar,
+  expectNoRuntimeDiagnostics,
+  waitForToolbar,
+} from "./support/debug-ui.js";
+import { debugApps, fixtureTag } from "./support/environment.js";
+
+const postTag = fixtureTag("prgPost");
+const getTag = fixtureTag("prgGet");
+const postTagPattern = new RegExp(`[?&]tag=${postTag}(?:&|$)`);
+
+for (const app of debugApps()) {
+  test(`${app.name} Mail chip label opens the capture that sent the mail`, async ({
+    page,
+  }) => {
+    test.skip(
+      app.id === "yii3",
+      "Yii3 has no Mail panel until the Phase 5 port.",
+    );
+
+    const diagnostics = collectRuntimeDiagnostics(page);
+
+    // Serve the page toolbar from the seeded GET that follows the mail-sending POST; later AJAX loads are untouched.
+    await page.route(
+      /toolbar-data/,
+      (route) => {
+        const url = new URL(route.request().url());
+
+        url.searchParams.set("tag", getTag);
+
+        return route.continue({ url: url.href });
+      },
+      { times: 1 },
+    );
+
+    const response = await page.goto(app.baseURL, {
+      waitUntil: "domcontentloaded",
+    });
+
+    expect(response?.ok(), `${app.baseURL} must load successfully`).toBe(true);
+
+    const toolbar = await waitForToolbar(page);
+    await expandToolbar(toolbar);
+
+    const mail = toolbar.getByRole("group", { name: "Mail" });
+    const label = mail.locator(".panel-link");
+    const badge = mail.locator(".metric");
+
+    await expect(label).toHaveAttribute("data-debug-url", postTagPattern);
+    await expect(badge).toHaveAttribute(
+      "data-debug-url",
+      (await label.getAttribute("data-debug-url")) ?? "",
+    );
+
+    await label.click();
+
+    const frame = toolbar.locator("iframe[title='Yii debug panel']");
+
+    await expect(frame).toHaveAttribute("src", postTagPattern);
+    await expect(
+      frame.contentFrame().locator(".yii-debug-page").first(),
+    ).toContainText("Toolbar PRG fixture message 0");
+    await expectNoRuntimeDiagnostics(diagnostics, `${app.name} Mail chip`);
+  });
+}

package.json

@@ -23,7 +23,7 @@
     "check:icons:strict": "node tools/check-icons.mjs --strict",
     "contact-sheet": "node tools/contact-sheet.mjs",
     "test:events": "DEBUG_UI_SEED_FIXTURES=0 playwright test e2e/events.spec.js",
-    "test:e2e": "playwright test e2e/smoke.spec.js e2e/security.spec.js e2e/db-controls.spec.js e2e/history-layout.spec.js",
+    "test:e2e": "playwright test e2e/smoke.spec.js e2e/security.spec.js e2e/db-controls.spec.js e2e/history-layout.spec.js e2e/toolbar-mail.spec.js",
     "test:e2e:list": "DEBUG_UI_SEED_FIXTURES=0 playwright test --list",
     "test:a11y": "playwright test e2e/accessibility.spec.js",
     "test:security": "playwright test e2e/security.spec.js",
@@ -32,7 +32,7 @@
     "test:visual:update": "DEBUG_UI_VISUAL_COMPARE=1 playwright test e2e/visual.spec.js --update-snapshots",
     "test:perf": "DEBUG_UI_SEED_FIXTURES=0 playwright test e2e/large-data.spec.js --project=desktop-1440",
     "test:perf:live": "playwright test e2e/live-performance.spec.js --project=desktop-1440",
-    "test:browser": "playwright test e2e/smoke.spec.js e2e/security.spec.js e2e/db-controls.spec.js e2e/history-layout.spec.js e2e/accessibility.spec.js e2e/visual.spec.js e2e/events.spec.js"
+    "test:browser": "playwright test e2e/smoke.spec.js e2e/security.spec.js e2e/db-controls.spec.js e2e/history-layout.spec.js e2e/toolbar-mail.spec.js e2e/accessibility.spec.js e2e/visual.spec.js e2e/events.spec.js"
   },
   "engines": {
     "node": "^22.12.0 || >=24.0.0"

tools/quality/fixture-contract.json

@@ -20,6 +20,14 @@
             "tag": "quality-fixture-dense-v1",
             "timestamp": 1787529601.0,
             "rows": 80
+        },
+        "prgPost": {
+            "tag": "toolbar-prg-post-v1",
+            "timestamp": 1787529602.0
+        },
+        "prgGet": {
+            "tag": "toolbar-prg-get-v1",
+            "timestamp": 1787529603.0
         }
     },
     "apps": [

tools/seed-debug-fixtures.php

@@ -313,6 +313,53 @@ function emptyPanels(float $timestamp): array
     );
 }
 
+/**
+ * Builds one half of a POST-redirect-GET pair: the POST sends `$mailCount` messages, the GET that follows sends none,
+ * so the host toolbar must surface the POST's mail as a cross-request chip on the GET.
+ *
+ * @return array<string, array<string, mixed>>
+ */
+function prgPanels(float $timestamp, string $method, int $mailCount): array
+{
+    $panels = emptyPanels($timestamp);
+
+    $panels['request'] = RequestSnapshot::capture(
+        [
+            'statusCode' => $method === 'POST' ? 302 : 200,
+            'general' => ['method' => $method],
+            'requestHeaders' => [],
+            'responseHeaders' => [],
+            'requestBody' => [],
+            'GET' => [],
+            'POST' => [],
+            'FILES' => [],
+            'COOKIE' => [],
+            'SERVER' => [],
+        ],
+    )->jsonSerialize();
+    $panels['mail'] = [
+        'entries' => rows(
+            $mailCount,
+            static fn(int $index): array => [
+                'from' => 'Debug Fixture <fixture@example.test>',
+                'to' => ["prg-recipient-{$index}@example.test"],
+                'cc' => [],
+                'bcc' => [],
+                'replyTo' => [],
+                'subject' => "Toolbar PRG fixture message {$index}",
+                'body' => "Sent by the POST half of the toolbar PRG fixture {$index}.",
+                'headers' => "From: fixture@example.test\nX-Quality-Fixture: prg-{$index}",
+                'charset' => 'UTF-8',
+                'file' => '',
+                'isSuccessful' => true,
+                'time' => (int) $timestamp + $index,
+            ],
+        ),
+    ];
+
+    return normalizePanels($panels);
+}
+
 /**
  * @param array<string, string> $sensitiveFixture
  *
@@ -729,11 +776,12 @@ function snapshot(
     float $timestamp,
     array $panels,
     int $statusCode,
+    string $method = 'GET',
 ): DebugSnapshot {
     $dbEntries = $panels['db']['entries'] ?? null;
     $mailEntries = $panels['mail']['entries'] ?? null;
     $summary = RequestSummary::create($tag)
-        ->withRequest(url: $url, method: 'GET', ip: '127.0.0.1', time: $timestamp)
+        ->withRequest(url: $url, method: $method, ip: '127.0.0.1', time: $timestamp)
         ->withResponse($statusCode)
         ->withDatabase(is_array($dbEntries) ? count($dbEntries) : 0)
         ->withMail(is_array($mailEntries) ? count($mailEntries) : 0, [])
@@ -818,14 +866,24 @@ function assertPersistedRedaction(string $file, array $contract): void
 $targets = resolveTargets($contract, $options);
 $states = $contract['states'] ?? null;
 
-if (!is_array($states) || !is_array($states['empty'] ?? null) || !is_array($states['dense'] ?? null)) {
+if (
+    !is_array($states)
+    || !is_array($states['empty'] ?? null)
+    || !is_array($states['dense'] ?? null)
+    || !is_array($states['prgPost'] ?? null)
+    || !is_array($states['prgGet'] ?? null)
+) {
     throw new RuntimeException("Fixture contract field 'states' is incomplete.");
 }
 
 $emptyTag = $states['empty']['tag'] ?? null;
 $emptyTime = $states['empty']['timestamp'] ?? null;
 $denseTag = $states['dense']['tag'] ?? null;
 $denseTime = $states['dense']['timestamp'] ?? null;
+$prgPostTag = $states['prgPost']['tag'] ?? null;
+$prgPostTime = $states['prgPost']['timestamp'] ?? null;
+$prgGetTag = $states['prgGet']['tag'] ?? null;
+$prgGetTime = $states['prgGet']['timestamp'] ?? null;
 $rowCount = $options['rows'] ?? ($states['dense']['rows'] ?? null);
 $rowCount = is_string($rowCount) && ctype_digit($rowCount) ? (int) $rowCount : $rowCount;
 
@@ -834,6 +892,10 @@ function assertPersistedRedaction(string $file, array $contract): void
     || !is_numeric($emptyTime)
     || !is_string($denseTag)
     || !is_numeric($denseTime)
+    || !is_string($prgPostTag)
+    || !is_numeric($prgPostTime)
+    || !is_string($prgGetTag)
+    || !is_numeric($prgGetTime)
     || !is_int($rowCount)
     || $rowCount < 1
     || $rowCount > 5_000
@@ -855,7 +917,7 @@ function assertPersistedRedaction(string $file, array $contract): void
         );
     }
 
-    $historySize = max(200, count($manifest->entries) + 2);
+    $historySize = max(200, count($manifest->entries) + 4);
     $empty = snapshot(
         $emptyTag,
         $target['baseURL'] . '/quality-fixture/empty',
@@ -871,17 +933,38 @@ function assertPersistedRedaction(string $file, array $contract): void
         200,
     );
 
-    // Upsert the stable tags without deleting developers' live snapshots.
+    $prgPost = snapshot(
+        $prgPostTag,
+        $target['baseURL'] . '/quality-fixture/prg',
+        (float) $prgPostTime,
+        prgPanels((float) $prgPostTime, 'POST', 1),
+        302,
+        'POST',
+    );
+    $prgGet = snapshot(
+        $prgGetTag,
+        $target['baseURL'] . '/quality-fixture/prg',
+        (float) $prgGetTime,
+        prgPanels((float) $prgGetTime, 'GET', 0),
+        200,
+    );
+
+    // Upsert the stable tags without deleting developers' live snapshots. Each write moves its tag to the newest
+    // manifest position, so the PRG pair stays adjacent with the GET immediately after the POST.
     $store->writeSnapshot($empty, $historySize);
     $store->writeSnapshot($dense, $historySize);
+    $store->writeSnapshot($prgPost, $historySize);
+    $store->writeSnapshot($prgGet, $historySize);
     assertPersistedRedaction($target['path'] . "/runtime/debug/{$denseTag}.json", $contract);
 
     if (!isset($options['quiet'])) {
         printf(
-            "%s: seeded %s and %s (%d dense rows) in %s\n",
+            "%s: seeded %s, %s, %s and %s (%d dense rows) in %s\n",
             $target['name'],
             $emptyTag,
             $denseTag,
+            $prgPostTag,
+            $prgGetTag,
             $rowCount,
             $target['path'] . '/runtime/debug',
         );