tests(full-page-screenshot): add node verification and debug tool (#1…

…5324)
GoogleChrome · Mar 8, 2024 · 62bcd98 · 62bcd98
1 parent ab9be18
commit 62bcd98
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Showing 6 changed files with 485 additions and 6 deletions.
diff --git a/cli/test/fixtures/screenshot-nodes.html b/cli/test/fixtures/screenshot-nodes.html
@@ -0,0 +1,59 @@
+<!--
+ * Copyright 2023 The Lighthouse Authors. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
+-->
+
+<head>
+  <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1">
+  <style>
+    p {
+      background-color: white;
+    }
+
+    div {
+      width: 150px;
+    }
+    div,span,img {
+      margin: 10px;
+      padding: 5px;
+    }
+    /* Want a LCP, but not any image or text visible! */
+    img {
+      opacity: 0.001;
+    }
+    span {
+      display: inline-block;
+    }
+
+    [id*='red'],span[id*='red'] {
+      background-color: #8a4343;
+    }
+    [id*='green'],span[id*='green'] {
+      background-color: #427f36;
+    }
+  </style>
+</head>
+
+<body>
+  <p id="textEl"></p>
+
+  <script>
+    const params = new URLSearchParams(document.location.search);
+    if (params.has('grow')) {
+      textEl.style.backgroundColor = 'lightgrey';
+      let padding = 1;
+      setInterval(() => {
+        if (padding > 300) return;
+
+        textEl.style.paddingTop = padding + 'px';
+        padding += 1;
+      }, 50);
+    }
+  </script>
+
+  <div id="el-1-red" role="treeitem"></div>
+  <div id="red">
+    <span id="green"><img id="el-2-green" src="launcher-icon-4x.png" width="50" height="50"></span>
+  </div>
+</body>
diff --git a/core/gather/gatherers/full-page-screenshot.js b/core/gather/gatherers/full-page-screenshot.js
@@ -13,7 +13,10 @@ import {waitForNetworkIdle} from '../driver/wait-for-condition.js';
 // JPEG quality setting
 // Exploration and examples of reports using different quality settings: https://docs.google.com/document/d/1ZSffucIca9XDW2eEwfoevrk-OTl7WQFeMf0CgeJAA8M/edit#
 // Note: this analysis was done for JPEG, but now we use WEBP.
-const FULL_PAGE_SCREENSHOT_QUALITY = 30;
+const FULL_PAGE_SCREENSHOT_QUALITY = process.env.LH_FPS_TEST ? 100 : 30;
+// webp currently cant do lossless encoding, so to help tests switch to png
+// Remove when this is resolved: https://bugs.chromium.org/p/chromium/issues/detail?id=1469183
+const FULL_PAGE_SCREENSHOT_FORMAT = process.env.LH_FPS_TEST ? 'png' : 'webp';
 
 // https://developers.google.com/speed/webp/faq#what_is_the_maximum_size_a_webp_image_can_be
 const MAX_WEBP_SIZE = 16383;
@@ -121,10 +124,10 @@ class FullPageScreenshot extends BaseGatherer {
    */
   async _takeScreenshot(context) {
     const result = await context.driver.defaultSession.sendCommand('Page.captureScreenshot', {
-      format: 'webp',
+      format: FULL_PAGE_SCREENSHOT_FORMAT,
       quality: FULL_PAGE_SCREENSHOT_QUALITY,
     });
-    const data = 'data:image/webp;base64,' + result.data;
+    const data = `data:image/${FULL_PAGE_SCREENSHOT_FORMAT};base64,` + result.data;
 
     const screenshotAreaSize =
       await context.driver.executionContext.evaluate(getScreenshotAreaSize, {
@@ -159,7 +162,7 @@ class FullPageScreenshot extends BaseGatherer {
       for (const [node, id] of lhIdToElements.entries()) {
         // @ts-expect-error - getBoundingClientRect put into scope via stringification
         const rect = getBoundingClientRect(node);
-        nodes[id] = rect;
+        nodes[id] = {id: node.id, ...rect};
       }
 
       return nodes;

diff --git a/core/scripts/full-page-screenshot-debug.js b/core/scripts/full-page-screenshot-debug.js
@@ -0,0 +1,95 @@
+/**
+ * @license Copyright 2023 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
+ */
+
+// To open result in chrome:
+//   node core/scripts/full-page-screenshot-debug.js latest-run/lhr.report.json | xargs "$CHROME_PATH"
+
+import * as fs from 'fs';
+
+import esMain from 'es-main';
+import * as puppeteer from 'puppeteer-core';
+import {getChromePath} from 'chrome-launcher';
+
+import {LH_ROOT} from '../../shared/root.js';
+
+/**
+ * @param {LH.Result} lhr
+ * @return {Promise<string>}
+ */
+async function getDebugImage(lhr) {
+  if (!lhr.fullPageScreenshot) {
+    return '';
+  }
+
+  const browser = await puppeteer.launch({
+    headless: true,
+    executablePath: getChromePath(),
+    ignoreDefaultArgs: ['--enable-automation'],
+  });
+  const page = await browser.newPage();
+
+  const debugDataUrl = await page.evaluate(async (fullPageScreenshot) => {
+    const img = await new Promise((resolve, reject) => {
+      // eslint-disable-next-line no-undef
+      const img = new Image();
+      img.onload = () => resolve(img);
+      img.onerror = reject;
+      img.src = fullPageScreenshot.screenshot.data;
+    });
+
+    // eslint-disable-next-line no-undef
+    const canvasEl = document.createElement('canvas');
+    canvasEl.width = img.width;
+    canvasEl.height = img.height;
+    const ctx = canvasEl.getContext('2d');
+    if (!ctx) return '';
+
+    ctx.drawImage(img, 0, 0);
+    for (const [lhId, node] of Object.entries(fullPageScreenshot.nodes)) {
+      if (!node.width && !node.height) continue;
+
+      ctx.strokeStyle = '#D3E156';
+      ctx.lineWidth = 2;
+      ctx.beginPath();
+      ctx.rect(node.left, node.top, node.width, node.height);
+      ctx.stroke();
+
+      const txt = node.id || lhId;
+      const txtWidth = Math.min(ctx.measureText(txt).width, node.width);
+      const txtHeight = 10;
+      const txtTop = node.top - 3;
+      const txtLeft = node.left;
+      ctx.fillStyle = '#FFFFFF88';
+      ctx.fillRect(txtLeft, txtTop, txtWidth, txtHeight);
+      ctx.fillStyle = '#000000';
+      ctx.lineWidth = 1;
+      ctx.textBaseline = 'top';
+      ctx.fillText(txt, txtLeft, txtTop);
+    }
+
+    return canvasEl.toDataURL();
+  }, lhr.fullPageScreenshot);
+
+  await browser.close();
+
+  if (!debugDataUrl.startsWith('data:image/')) {
+    throw new Error('invalid data url');
+  }
+
+  return debugDataUrl;
+}
+
+if (esMain(import.meta)) {
+  const lhr = JSON.parse(fs.readFileSync(process.argv[2], 'utf-8'));
+  const imageUrl = await getDebugImage(lhr);
+  const [type, base64Data] = imageUrl.split(',');
+  const ext = type.replace('data:image/', '');
+  const dest = `${LH_ROOT}/.tmp/fps-debug.${ext}`;
+  fs.writeFileSync(dest, base64Data, 'base64');
+  console.log(dest);
+}
+
+export {getDebugImage};