fix tests with file server host (#38138)

e2e-tests/cypress/tests/integration/channels/files_and_attachments/upload_files_spec.js

@@ -27,6 +27,9 @@ describe('Upload Files', () => {
         // # Login as sysadmin
         cy.apiAdminLogin();
 
+        // # Ensure standard message display (download aria-label is omitted in compact)
+        cy.apiSaveMessageDisplayPreference('clean');
+
         // # Init setup
         cy.apiInitSetup().then((out) => {
             channelUrl = out.channelUrl;

e2e-tests/playwright/lib/src/containers/mattermost_container.ts

@@ -47,15 +47,15 @@ function structuralEnv(): Record<string, string> {
         MM_EMAILSETTINGS_SMTPSERVER: INBUCKET_ALIAS,
         MM_EMAILSETTINGS_SMTPPORT: String(INBUCKET_SMTP_PORT),
         ...(process.env.MM_LICENSE ? {MM_LICENSE: process.env.MM_LICENSE} : {}),
-        // Overrides (not merges) SERVER_ENV_BASELINE's own value for this same key — appends the
-        // network's gateway IP so the SSRF guard also allows fetching from file_server.ts's mock
-        // file server, reachable at that address (see test_config.ts). Only known once the
-        // network is up (testConfig.testcontainersNetworkGatewayIp is set by stack.ts's
-        // startStack() before this container ever starts), so falls back to the baseline's own
-        // value verbatim on the off chance this ever runs without it.
-        MM_SERVICESETTINGS_ALLOWEDUNTRUSTEDINTERNALCONNECTIONS: testConfig.testcontainersNetworkGatewayIp
-            ? `${SERVER_ENV_BASELINE.MM_SERVICESETTINGS_ALLOWEDUNTRUSTEDINTERNALCONNECTIONS} ${testConfig.testcontainersNetworkGatewayIp}`
-            : SERVER_ENV_BASELINE.MM_SERVICESETTINGS_ALLOWEDUNTRUSTEDINTERNALCONNECTIONS,
+        // Replaces the baseline for this key: appends mock file-server hosts (host.docker.internal
+        // and the bridge gateway IP, set by startStack() once the network is up).
+        MM_SERVICESETTINGS_ALLOWEDUNTRUSTEDINTERNALCONNECTIONS: [
+            SERVER_ENV_BASELINE.MM_SERVICESETTINGS_ALLOWEDUNTRUSTEDINTERNALCONNECTIONS,
+            'host.docker.internal',
+            testConfig.testcontainersNetworkGatewayIp,
+        ]
+            .filter(Boolean)
+            .join(' '),
     };
 }
 
@@ -85,6 +85,8 @@ export async function startMattermostContainer(
             .withNetworkMode(networkName)
             .withNetworkAliases(MATTERMOST_ALIAS)
             .withLabels(TESTCONTAINERS_LABELS)
+            // Ensures host.docker.internal resolves to the Docker host (via host-gateway).
+            .withExtraHosts([{host: 'host.docker.internal', ipAddress: 'host-gateway'}])
             .withExposedPorts(MATTERMOST_PORT)
             .withEnvironment(env)
             .withStartupTimeout(5 * 60_000)

e2e-tests/playwright/lib/src/file_server.ts

@@ -8,6 +8,9 @@ import {test} from './test_fixture';
 
 import {testConfig} from '@/test_config';
 
+/** Hostname containers use to reach the Docker host. */
+export const DOCKER_HOST_INTERNAL = 'host.docker.internal';
+
 /**
  * Starts a server that serves files from ./asset. When run from the monorepo, this will serve files from
  * e2e-tests/playwright/asset.
@@ -63,10 +66,18 @@ export function setupFileServer(): Promise<string> {
     });
 }
 
-// localhost isn't reachable from inside the Mattermost container in `testcontainers` mode (it resolves to
-// the container's own loopback, not the host's). testcontainersNetworkGatewayIp is reachable
-// from both the container and the host-side browser, so it works as a single URL for both — this
-// server binds to 0.0.0.0, not just loopback, to accept the former.
-function fileServerHost(): string {
-    return testConfig.useTestContainers ? testConfig.testcontainersNetworkGatewayIp : 'localhost';
+/**
+ * Host used in file-server URLs embedded in posts. Must be reachable from both the host-side
+ * browser (Markdown images load directly) and the Mattermost container (link previews / metadata).
+ * On macOS/Windows the bridge gateway does not reach host listeners, so use host.docker.internal;
+ * on Linux use the bridge gateway IP (works both sides; host.docker.internal is often absent from host DNS).
+ */
+export function fileServerHost(): string {
+    if (!testConfig.useTestContainers) {
+        return 'localhost';
+    }
+    if (process.platform === 'darwin' || process.platform === 'win32') {
+        return DOCKER_HOST_INTERNAL;
+    }
+    return testConfig.testcontainersNetworkGatewayIp || DOCKER_HOST_INTERNAL;
 }

e2e-tests/playwright/mock_file_server.js

@@ -14,7 +14,8 @@ const {createServer} = require('http');
 const fs = require('fs');
 const path = require('path');
 
-const PORT = Number(process.env.PORT) || 3011;
+// PORT=0 must request an ephemeral port — don't treat 0 as falsy and fall back to 3011.
+const PORT = process.env.PORT !== undefined && process.env.PORT !== '' ? Number(process.env.PORT) : 3011;
 const ASSET_DIR = process.env.ASSET_DIR || path.join(__dirname, 'asset');
 
 if (process.argv[2]) {

e2e-tests/playwright/specs/functional/channels/post_list/initial_scroll_read.spec.ts

@@ -176,7 +176,6 @@ test.describe('Post list initial scroll in read channel', () => {
 
     async function waitForScrollToSettle(watcher: PostListScrollWatcher) {
         await channelsPage.centerView.toBeVisible();
-        await page.waitForLoadState('networkidle');
 
         // # Wait until the post list hasn't scrolled for 500ms before returning results
         return watcher.waitForObservations(500);

e2e-tests/playwright/specs/functional/channels/post_list/initial_scroll_unread.spec.ts

@@ -194,8 +194,6 @@ test.describe('Post list initial scroll in unread channel', () => {
                 await channelsPage.goto(team.name, 'town-square');
                 await channelsPage.centerView.getLastPost();
 
-                await page.waitForLoadState('networkidle');
-
                 // * Verify that the channel starts as unread
                 await channelsPage.sidebarLeft.assertItemUnread(channel.name);
 
@@ -220,7 +218,6 @@ test.describe('Post list initial scroll in unread channel', () => {
 
     async function waitForScrollToSettle(watcher: PostListScrollWatcher) {
         await channelsPage.centerView.toBeVisible();
-        await page.waitForLoadState('networkidle');
 
         // # Wait until the post list hasn't scrolled for 500ms before returning results
         return watcher.waitForObservations(500);

e2e-tests/playwright/specs/functional/channels/post_list/permalink_scroll.spec.ts

@@ -281,7 +281,6 @@ test.describe('Post list scroll to permalink', () => {
 
     async function waitForScrollToSettle(watcher: PostListScrollWatcher) {
         await channelsPage.centerView.toBeVisible();
-        await page.waitForLoadState('networkidle');
 
         // # Wait until the post list hasn't scrolled for 500ms before returning results
         return watcher.waitForObservations(500);

e2e-tests/playwright/specs/functional/channels/post_list/post_height.spec.ts

@@ -38,9 +38,6 @@ test.describe('Post height', () => {
         });
 
         // # Enable SVG rendering and let the server fetch metadata from the mock file server.
-        // AllowedUntrustedInternalConnections only takes effect in `external` mode here — in
-        // `testcontainers` mode it's fixed at boot via an env var, and a PatchConfig on an env-controlled
-        // field is accepted but has no real effect.
         await adminClient.patchConfig({
             ServiceSettings: {
                 EnableSVGs: true,
@@ -465,9 +462,6 @@ test.describe('Post height', () => {
                     await testCase.additionalCheck({postComponent});
                 }
 
-                // # Wait for all network requests to finish
-                await page.waitForLoadState('networkidle');
-
                 // * Verify no height changes were detected
                 expect(await sizeWatcher.getObservations()).toHaveLength(1);
             },