Add Visual Test for Snow Theme and add visual tests to PR execution (#5570)

e2e/playwright-visual.config.js

@@ -2,12 +2,13 @@
 // playwright.config.js
 // @ts-check
 
-/** @type {import('@playwright/test').PlaywrightTestConfig} */
+/** @type {import('@playwright/test').PlaywrightTestConfig<{ theme: string }>} */
 const config = {
     retries: 0, // visual tests should never retry due to snapshot comparison errors
     testDir: 'tests/visual',
-    timeout: 90 * 1000,
-    workers: 1, // visual tests should never run in parallel due to test pollution
+    testMatch: '**/*.visual.spec.js', // only run visual tests
+    timeout: 60 * 1000,
+    workers: 2, //Limit to 2 for CircleCI Agent
     webServer: {
         command: 'cross-env NODE_ENV=test npm run start',
         url: 'http://localhost:8080/#',
@@ -15,17 +16,35 @@ const config = {
         reuseExistingServer: !process.env.CI
     },
     use: {
-        browserName: "chromium",
         baseURL: 'http://localhost:8080/',
-        headless: true, // this needs to remain headless to avoid visual changes due to GPU
+        headless: true, // this needs to remain headless to avoid visual changes due to GPU rendering in headed browsers
         ignoreHTTPSErrors: true,
         screenshot: 'on',
-        trace: 'off',
+        trace: 'on',
         video: 'off'
     },
+    projects: [
+        {
+            name: 'chrome',
+            use: {
+                browserName: 'chromium'
+            }
+        },
+        {
+            name: 'chrome-snow-theme',
+            use: {
+                browserName: 'chromium',
+                theme: 'snow'
+            }
+        }
+    ],
     reporter: [
         ['list'],
-        ['junit', { outputFile: 'test-results/results.xml' }]
+        ['junit', { outputFile: 'test-results/results.xml' }],
+        ['html', {
+            open: 'on-failure',
+            outputFolder: '../html-test-results' //Must be in different location due to https://github.com/microsoft/playwright/issues/12840
+        }]
     ]
 };