From 468c7f93705a4343a6575e16fee6a199d038c322 Mon Sep 17 00:00:00 2001
From: Adam Raine <ad.st.raine@gmail.com>
Date: Thu, 7 Mar 2024 18:26:19 -0800
Subject: [PATCH] faster test

---
 core/gather/gatherers/full-page-screenshot.js | 25 ++++++++++++-------
 .../gatherers/full-page-screenshot-test.js    | 15 +++++++----
 2 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/core/gather/gatherers/full-page-screenshot.js b/core/gather/gatherers/full-page-screenshot.js
index ad0861ee723e..1d8ca13deb73 100644
--- a/core/gather/gatherers/full-page-screenshot.js
+++ b/core/gather/gatherers/full-page-screenshot.js
@@ -58,6 +58,21 @@ class FullPageScreenshot extends BaseGatherer {
     supportedModes: ['snapshot', 'timespan', 'navigation'],
   };
 
+  /**
+   * @param {LH.Gatherer.Context} context
+   */
+  waitForNetworkIdle(context) {
+    const session = context.driver.defaultSession;
+    const networkMonitor = context.driver.networkMonitor;
+    return waitForNetworkIdle(session, networkMonitor, {
+      pretendDCLAlreadyFired: true,
+      networkQuietThresholdMs: 1000,
+      busyEvent: 'network-critical-busy',
+      idleEvent: 'network-critical-idle',
+      isIdle: recorder => recorder.isCriticalIdle(),
+    });
+  }
+
   /**
    * @param {LH.Gatherer.Context} context
    * @param {{height: number, width: number, mobile: boolean}} deviceMetrics
@@ -75,15 +90,7 @@ class FullPageScreenshot extends BaseGatherer {
     );
     const height = Math.min(fullHeight, MAX_WEBP_SIZE);
 
-    // Setup network monitor before we change the viewport.
-    const networkMonitor = context.driver.networkMonitor;
-    const waitForNetworkIdleResult = waitForNetworkIdle(session, networkMonitor, {
-      pretendDCLAlreadyFired: true,
-      networkQuietThresholdMs: 1000,
-      busyEvent: 'network-critical-busy',
-      idleEvent: 'network-critical-idle',
-      isIdle: recorder => recorder.isCriticalIdle(),
-    });
+    const waitForNetworkIdleResult = this.waitForNetworkIdle(context);
 
     await session.sendCommand('Emulation.setDeviceMetricsOverride', {
       mobile: deviceMetrics.mobile,
diff --git a/core/test/gather/gatherers/full-page-screenshot-test.js b/core/test/gather/gatherers/full-page-screenshot-test.js
index 9a6675b4c814..bc0f5924d47f 100644
--- a/core/test/gather/gatherers/full-page-screenshot-test.js
+++ b/core/test/gather/gatherers/full-page-screenshot-test.js
@@ -5,6 +5,7 @@
 
 import {createMockContext} from '../../gather/mock-driver.js';
 import FullPageScreenshotGatherer from '../../../gather/gatherers/full-page-screenshot.js';
+import {fnAny} from '../../test-utils.js';
 
 /** @type {{width: number, height: number}} */
 let contentSize;
@@ -15,8 +16,17 @@ let screenshotSize;
 /** @type {string[]} */
 let screenshotData;
 let mockContext = createMockContext();
+let fpsGatherer = new FullPageScreenshotGatherer();
 
 beforeEach(() => {
+  fpsGatherer = new FullPageScreenshotGatherer();
+
+  // Prevent `waitForNetworkIdle` from stalling the tests
+  fpsGatherer.waitForNetworkIdle = fnAny().mockImplementation(() => ({
+    promise: Promise.resolve(),
+    cancel: fnAny(),
+  }));
+
   contentSize = {width: 100, height: 100};
   screenSize = {width: 100, height: 100, dpr: 1};
   screenshotSize = contentSize;
@@ -63,7 +73,6 @@ beforeEach(() => {
 
 describe('FullPageScreenshot gatherer', () => {
   it('captures a full-page screenshot', async () => {
-    const fpsGatherer = new FullPageScreenshotGatherer();
     contentSize = {width: 412, height: 2000};
     screenSize = {width: 412, height: 412};
     screenshotSize = contentSize;
@@ -92,7 +101,6 @@ describe('FullPageScreenshot gatherer', () => {
   });
 
   it('resets the emulation correctly when Lighthouse controls it', async () => {
-    const fpsGatherer = new FullPageScreenshotGatherer();
     contentSize = {width: 412, height: 2000};
     screenSize = {width: 412, height: 412};
     screenshotSize = contentSize;
@@ -126,7 +134,6 @@ describe('FullPageScreenshot gatherer', () => {
   });
 
   it('resets the emulation correctly when Lighthouse does not control it', async () => {
-    const fpsGatherer = new FullPageScreenshotGatherer();
     contentSize = {width: 500, height: 1500};
     screenSize = {width: 500, height: 500, dpr: 2};
     screenshotSize = contentSize;
@@ -172,8 +179,6 @@ describe('FullPageScreenshot gatherer', () => {
   });
 
   it('limits the screenshot height to the max Chrome can capture', async () => {
-    const fpsGatherer = new FullPageScreenshotGatherer();
-
     contentSize = {width: 412, height: 100000};
     screenSize = {width: 412, height: 412, dpr: 1};
     screenshotSize = contentSize;