Stabilize visual tests (#3001)

Author: gregberge

packages/gitbook/e2e/util.ts

@@ -191,21 +191,20 @@ export function runTestCases(testCases: TestsCase[]) {
                             .intercom-lightweight-app {
                                 display: none !important;
                             }
-
-                            /* Switch image rendering to pixelated */
-                            img {
-                                image-rendering: pixelated;
-                            }
                             `,
                             threshold: screenshotOptions?.threshold ?? undefined,
                             fullPage: testEntry.fullPage ?? false,
                             beforeScreenshot: async ({ runStabilization }) => {
                                 await runStabilization();
                                 await waitForIcons(page);
+                                await roundImageSizes(page);
                                 if (screenshotOptions?.waitForTOCScrolling !== false) {
                                     await waitForTOCScrolling(page);
                                 }
                             },
+                            afterScreenshot: async () => {
+                                await restoreImageSizes(page);
+                            },
                         });
                     }
                 });
@@ -326,7 +325,14 @@ async function waitForIcons(page: Page) {
         function loadImage(src: string) {
             return new Promise((resolve, reject) => {
                 const img = new Image();
-                img.onload = () => resolve(img);
+                img.onload = () => {
+                    // Wait two frames to ensure the image has been rendered
+                    requestAnimationFrame(() => {
+                        requestAnimationFrame(() => {
+                            resolve(true);
+                        });
+                    });
+                };
                 img.onerror = (_error) => reject(new Error(`Failed to load image: ${src}`));
                 img.src = src;
             });
@@ -348,6 +354,70 @@ async function waitForIcons(page: Page) {
     });
 }
 
+/**
+ * Take all images, measure them and set their width and height to rounded values.
+ */
+async function roundImageSizes(page: Page) {
+    await page.waitForFunction(async () => {
+        const images = Array.from(document.querySelectorAll('img'));
+        await Promise.all(
+            images.map(async (img) => {
+                return new Promise<void>((resolve) => {
+                    const setDimensions = () => {
+                        // Mark it as stabilized
+                        img.dataset.stabilized = 'true';
+                        // Preserve the original width and height
+                        img.dataset.originalWidth = img.style.width ?? '';
+                        img.dataset.originalHeight = img.style.height ?? '';
+                        const rect = img.getBoundingClientRect();
+                        img.style.width = `${Math.round(rect.width)}px`;
+                        img.style.height = `${Math.round(rect.height)}px`;
+                        resolve();
+                    };
+
+                    if (img.complete) {
+                        setDimensions();
+                    } else {
+                        const cleanup = () => {
+                            img.removeEventListener('load', handleLoad);
+                            img.removeEventListener('error', handleError);
+                        };
+                        const handleError = () => {
+                            cleanup();
+                            resolve();
+                        };
+                        const handleLoad = () => {
+                            cleanup();
+                            setDimensions();
+                        };
+                        img.addEventListener('load', handleLoad);
+                        img.addEventListener('error', handleError);
+                    }
+                });
+            })
+        );
+        return true;
+    });
+}
+
+/**
+ * Restore images to their original size.
+ */
+async function restoreImageSizes(page: Page) {
+    await page.evaluate(() => {
+        const images = Array.from(document.querySelectorAll('img[data-stabilized]'));
+        images.forEach((img) => {
+            if (img instanceof HTMLImageElement) {
+                img.style.width = img.dataset.originalWidth ?? '';
+                img.style.height = img.dataset.originalHeight ?? '';
+                delete img.dataset.originalWidth;
+                delete img.dataset.originalHeight;
+                delete img.dataset.stabilized;
+            }
+        });
+    });
+}
+
 /**
  * Wait for TOC to be correctly scrolled into view.
  */

packages/gitbook/playwright.config.ts

@@ -18,5 +18,8 @@ export default defineConfig({
     use: {
         trace: 'on-first-retry',
         screenshot: 'only-on-failure',
+        contextOptions: {
+            reducedMotion: 'reduce',
+        },
     },
 });

packages/gitbook/src/components/Search/SearchButton.tsx

@@ -115,9 +115,15 @@ function Shortcut() {
         setOperatingSystem(getOperatingSystem());
     }, []);
 
-    return operatingSystem ? (
+    return (
         <div
-            className={`shortcut -mr-1 hidden animate-fadeIn justify-end gap-0.5 whitespace-nowrap text-tint text-xs [font-feature-settings:"calt",_"case"] contrast-more:text-tint-strong md:flex`}
+            aria-busy={operatingSystem === null ? 'true' : undefined}
+            className={tcls(
+                `shortcut -mr-1 hidden justify-end gap-0.5 whitespace-nowrap text-tint text-xs [font-feature-settings:"calt",_"case"] contrast-more:text-tint-strong md:flex`,
+                operatingSystem
+                    ? 'motion-safe:animate-fadeIn motion-reduce:opacity-100'
+                    : 'opacity-0'
+            )}
         >
             <kbd
                 className={`flex h-5 min-w-5 items-center justify-center rounded border border-tint-subtle theme-bold:border-header-link/5 bg-tint-base theme-bold:bg-header-background px-1 ${operatingSystem === 'mac' ? 'text-sm' : ''}`}
@@ -128,7 +134,5 @@ function Shortcut() {
                 K
             </kbd>
         </div>
-    ) : (
-        <span aria-busy />
     );
 }

packages/gitbook/tailwind.config.ts

@@ -297,8 +297,8 @@ const config: Config = {
                 present: 'present .5s ease-out both',
                 scaleIn: 'scaleIn 200ms ease',
                 scaleOut: 'scaleOut 200ms ease',
-                fadeIn: 'fadeIn 200ms ease',
-                fadeOut: 'fadeOut 200ms ease',
+                fadeIn: 'fadeIn 200ms ease forwards',
+                fadeOut: 'fadeOut 200ms ease forwards',
                 enterFromLeft: 'enterFromLeft 250ms ease',
                 enterFromRight: 'enterFromRight 250ms ease',
                 exitToLeft: 'exitToLeft 250ms ease',