GoogleChrome · connorjclark · Mar 8, 2024 · Aug 1, 2023 · Aug 1, 2023 · Aug 1, 2023
@@ -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>
@@ -13,7 +13,7 @@
 // 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;
 
 // https://developers.google.com/speed/webp/faq#what_is_the_maximum_size_a_webp_image_can_be
 const MAX_WEBP_SIZE = 16383;
@@ -159,7 +159,7 @@
       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;

@@ -0,0 +1,83 @@
+/**
+ * @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"
+// But, it might be too large for xargs:
+//   node core/scripts/full-page-screenshot-debug.js latest-run/lhr.report.json | code -
+
+import * as fs from 'fs';
+
+import * as puppeteer from 'puppeteer-core';
+import {getChromePath} from 'chrome-launcher';
+
+/**
+ * @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();
+
+  return debugDataUrl;
+}
+
+const lhr = JSON.parse(fs.readFileSync(process.argv[2], 'utf-8'));
+const result = await getDebugImage(lhr);
+
+console.log(result);