CI : Add visual regression testing workflow based on Playwright and Argos.

.github/workflows/argos.yml

@@ -0,0 +1,36 @@
+name: Argos CI Screenshots
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  take-screenshots:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v4
+
+      - name: Use Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version: current
+
+      - name: Install dependencies
+        run: yarn install
+
+      - name: Install Playwright browsers
+        run: yarn playwright install --with-deps chromium
+
+      - name: Build the website
+        run: yarn docusaurus build
+
+      - name: Take screenshots with Playwright
+        run: yarn playwright test
+
+      - name: Upload screenshots to Argos
+        env:
+          ARGOS_TOKEN: ${{ secrets.ARGOS_TOKEN }}
+        run: yarn argos upload ./screenshots

docs/utils/argo_utils.ts

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+import * as cheerio from "cheerio";
+import * as fs from "fs";
+
+export function extractSitemapPathnames(sitemapPath: string): string[] {
+  const sitemap = fs.readFileSync(sitemapPath).toString();
+  const $ = cheerio.load(sitemap, { xmlMode: true });
+  const urls: string[] = [];
+  $("loc").each(function handleLoc() {
+    urls.push($(this).text());
+  });
+  return urls.map((url) => new URL(url).pathname);
+}
+
+// Converts a pathname to a decent screenshot name
+export function pathnameToArgosName(pathname: string): string {
+  return pathname.replace(/^\/|\/$/g, "") || "index";
+}

package.json

@@ -73,13 +73,17 @@
     "got": "^12.1.0"
   },
   "devDependencies": {
+    "@argos-ci/cli": "^2.5.5",
+    "@argos-ci/playwright": "^4.1.0",
     "@babel/core": "^7.26.0",
     "@babel/plugin-transform-modules-commonjs": "^7.25.9",
     "@babel/preset-env": "^7.26.0",
     "@babel/preset-react": "^7.25.9",
     "@babel/register": "^7.25.9",
+    "@playwright/test": "^1.50.0",
     "@typescript-eslint/eslint-plugin": "4.22.0",
     "@untitaker/hyperlink": "^0.1.32",
+    "cheerio": "^1.0.0",
     "eslint": "^7.24.0",
     "eslint-config-prettier": "^8.2.0",
     "eslint-import-resolver-typescript": "^2.4.0",

playwright.config.ts

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+import {devices} from '@playwright/test';
+import type {PlaywrightTestConfig} from '@playwright/test';
+
+const config: PlaywrightTestConfig = {
+  webServer: {
+    port: 3000,
+    command: 'yarn docusaurus serve',
+  },
+  projects: [
+    {
+      name: 'chromium',
+      use: {
+        ...devices['Desktop Chrome'],
+      },
+    },
+  ],
+};
+
+export default config;

screenshot.css

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+iframe,
+.avatar__photo,
+img[src$='.gif'],
+.DocSearch-Button-Keys > kbd,
+[class*='playgroundPreview'] {
+  visibility: hidden;
+}
+
+.theme-last-updated,
+.docusaurus-mermaid-container {
+  display: none;
+}

screenshot.spec.ts

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+import * as fs from 'fs';
+import { test } from '@playwright/test';
+import { argosScreenshot } from '@argos-ci/playwright';
+import { extractSitemapPathnames, pathnameToArgosName } from './docs/utils/argo_utils';
+
+// Constants
+const siteUrl = 'http://localhost:3000';
+const sitemapPath = './build/sitemap.xml';
+const stylesheetPath = './screenshot.css';
+const stylesheet = fs.readFileSync(stylesheetPath).toString();
+
+// Wait for hydration
+function waitForDocusaurusHydration() {
+  return document.documentElement.dataset.hasHydrated === 'true';
+}
+
+function screenshotPathname(pathname: string) {
+  test(`pathname ${pathname}`, async ({ page }) => {
+    const url = siteUrl + pathname;
+    await page.goto(url);
+    await page.waitForFunction(waitForDocusaurusHydration);
+    await page.addStyleTag({ content: stylesheet });
+    await argosScreenshot(page, pathnameToArgosName(pathname));
+  });
+}
+
+test.describe('Docusaurus site screenshots', () => {
+  const pathnames = extractSitemapPathnames(sitemapPath);
+  console.log('Pathnames to screenshot:', pathnames);
+  const filteredPathnames = pathnames.filter((pathname) => !pathname.includes('/1.0.0/'));
+  console.log('Filtered Pathnames:', filteredPathnames);
+
+  filteredPathnames.forEach(screenshotPathname);
+});