test(desktop): latch channel validation reads

Co-authored-by: npub1mprnacetjua2xx3p5eddmhxyk6wv929ymm5py8kd2xfxurxahspqqlgyta <d8473ee32b973aa31a21a65adddcc4b69cc2a8a4dee8121ecd51926e0cddbc02@buzz.block.builderlab.xyz>
Signed-off-by: npub1mprnacetjua2xx3p5eddmhxyk6wv929ymm5py8kd2xfxurxahspqqlgyta <d8473ee32b973aa31a21a65adddcc4b69cc2a8a4dee8121ecd51926e0cddbc02@buzz.block.builderlab.xyz>

desktop/src/testing/e2eBridge.ts

@@ -1254,6 +1254,12 @@ declare global {
     __BUZZ_E2E_RELEASE_OBSERVER_ARCHIVE_POLICY__?: () => number;
     /** Number of observer archive policy commands currently held by the seam. */
     __BUZZ_E2E_OBSERVER_ARCHIVE_POLICY_PENDING__?: number;
+    /** Hold channel reads until released. */
+    __BUZZ_E2E_DEFER_NEXT_CHANNELS_READ__?: () => void;
+    /** Release every channel read held by the explicit E2E seam. */
+    __BUZZ_E2E_RELEASE_CHANNELS_READ__?: () => number;
+    /** Number of channel reads currently held by the seam. */
+    __BUZZ_E2E_CHANNELS_READ_PENDING__?: number;
   }
 }
 
@@ -1358,6 +1364,8 @@ type DeferredGetEvent = {
 };
 let deferredGetEventQueue: DeferredGetEvent[] = [];
 let deferredObserverArchivePolicyQueue: Array<() => void> = [];
+let deferChannelsReads = false;
+let deferredChannelsReadQueue: Array<() => void> = [];
 
 const mockDisplayNames = new Map<string, string>([
   [MOCK_IDENTITY_PUBKEY, DEFAULT_MOCK_IDENTITY.display_name],
@@ -9783,6 +9791,19 @@ export function maybeInstallE2eTauriMocks() {
     for (const resolve of queued) resolve();
     return queued.length;
   };
+  deferChannelsReads = false;
+  deferredChannelsReadQueue = [];
+  window.__BUZZ_E2E_CHANNELS_READ_PENDING__ = 0;
+  window.__BUZZ_E2E_DEFER_NEXT_CHANNELS_READ__ = () => {
+    deferChannelsReads = true;
+  };
+  window.__BUZZ_E2E_RELEASE_CHANNELS_READ__ = () => {
+    deferChannelsReads = false;
+    const queued = deferredChannelsReadQueue.splice(0);
+    window.__BUZZ_E2E_CHANNELS_READ_PENDING__ = 0;
+    for (const resolve of queued) resolve();
+    return queued.length;
+  };
   window.__BUZZ_E2E_RELEASE_GET_EVENT__ = () => {
     const queued = deferredGetEventQueue.splice(0);
     for (const entry of queued) {
@@ -11087,6 +11108,13 @@ export function maybeInstallE2eTauriMocks() {
           activeConfig,
         );
       case "get_channels":
+        if (deferChannelsReads) {
+          await new Promise<void>((resolve) => {
+            deferredChannelsReadQueue.push(resolve);
+            window.__BUZZ_E2E_CHANNELS_READ_PENDING__ =
+              deferredChannelsReadQueue.length;
+          });
+        }
         return handleGetChannels(activeConfig);
       case "get_feed":
         return handleGetFeed(

desktop/tests/e2e/community-rail.spec.ts

@@ -448,14 +448,7 @@ test.describe("community rail", () => {
   test("does not repair a remembered channel until live validation succeeds", async ({
     page,
   }) => {
-    await installMockBridge(
-      page,
-      {
-        channelsReadDelayMs: 300,
-        channelsReadErrors: [null, "temporary channel read failure"],
-      },
-      { skipCommunitySeed: true },
-    );
+    await installMockBridge(page, undefined, { skipCommunitySeed: true });
     await seedCommunities(page, [COMMUNITY_A, COMMUNITY_B], COMMUNITY_A.id);
     await page.addInitScript((communityId) => {
       window.localStorage.setItem(
@@ -488,20 +481,39 @@ test.describe("community rail", () => {
         JSON.stringify(snapshot),
       );
     });
+    await page.evaluate(() => {
+      const deferNextChannelsRead = (
+        window as Window & {
+          __BUZZ_E2E_DEFER_NEXT_CHANNELS_READ__?: () => void;
+        }
+      ).__BUZZ_E2E_DEFER_NEXT_CHANNELS_READ__;
+      if (!deferNextChannelsRead) {
+        throw new Error("missing channel-read defer seam");
+      }
+      deferNextChannelsRead();
+    });
 
+    await page.evaluate(() => {
+      const invalidateChannels = (
+        window as Window & {
+          __BUZZ_E2E_INVALIDATE_CHANNELS__?: () => Promise<void>;
+        }
+      ).__BUZZ_E2E_INVALIDATE_CHANNELS__;
+      if (!invalidateChannels) {
+        throw new Error("missing channel invalidation seam");
+      }
+      void invalidateChannels();
+    });
+    await page.waitForFunction(
+      () =>
+        (
+          window as Window & {
+            __BUZZ_E2E_CHANNELS_READ_PENDING__?: number;
+          }
+        ).__BUZZ_E2E_CHANNELS_READ_PENDING__ === 1,
+    );
     await page.getByTestId(`community-rail-button-${COMMUNITY_B.id}`).click();
-    await expect(page).toHaveURL(/#\/channels\/general$/);
-    await expect
-      .poll(() =>
-        page.evaluate((communityId) => {
-          const raw = window.localStorage.getItem(
-            "buzz-community-destinations",
-          );
-          return raw ? JSON.parse(raw)[communityId] : null;
-        }, COMMUNITY_B.id),
-      )
-      .toEqual({ kind: "channel", channelId: "general" });
-    await page.waitForTimeout(400);
+    await expect(page).not.toHaveURL(/#\/channels\/general$/);
     await expect
       .poll(() =>
         page.evaluate((communityId) => {
@@ -513,7 +525,44 @@ test.describe("community rail", () => {
       )
       .toEqual({ kind: "channel", channelId: "general" });
 
-    await expect(page.getByTestId("channel-general")).toBeVisible();
+    await page.evaluate(() => {
+      const config = (
+        window as Window & {
+          __BUZZ_E2E__?: {
+            mock?: { channelsReadErrors?: (string | null)[] };
+          };
+        }
+      ).__BUZZ_E2E__;
+      if (!config) throw new Error("missing E2E config");
+      config.mock = {
+        ...config.mock,
+        channelsReadErrors: ["temporary channel read failure"],
+      };
+    });
+    await expect
+      .poll(() =>
+        page.evaluate(
+          () => window.__BUZZ_E2E__?.mock?.channelsReadErrors?.length ?? 0,
+        ),
+      )
+      .toBe(1);
+    const released = await page.evaluate(
+      () =>
+        (
+          window as Window & {
+            __BUZZ_E2E_RELEASE_CHANNELS_READ__?: () => number;
+          }
+        ).__BUZZ_E2E_RELEASE_CHANNELS_READ__?.() ?? 0,
+    );
+    expect(released).toBe(1);
+    await expect
+      .poll(() =>
+        page.evaluate(
+          () => window.__BUZZ_E2E__?.mock?.channelsReadErrors?.length ?? 0,
+        ),
+      )
+      .toBe(0);
+
     await expect
       .poll(() =>
         page.evaluate((communityId) => {