test: move playwright test suite to top level (#2113)

tests/kit/playwright.ts

@@ -0,0 +1,55 @@
+import crypto from 'node:crypto';
+import fs from 'node:fs';
+import path from 'node:path';
+import process from 'node:process';
+
+import { test as baseTest } from '@playwright/test';
+
+const istanbulTempDir = process.env.ISTANBUL_TEMP_DIR
+  ? path.resolve(process.env.ISTANBUL_TEMP_DIR)
+  : path.join(process.cwd(), '.nyc_output');
+
+function generateUUID() {
+  return crypto.randomUUID();
+}
+
+const enableCoverage = !!process.env.CI || !!process.env.COVERAGE;
+
+export const test = baseTest.extend({
+  context: async ({ context }, use) => {
+    if (enableCoverage) {
+      await context.addInitScript(() =>
+        window.addEventListener('beforeunload', () =>
+          // @ts-expect-error
+          window.collectIstanbulCoverage(JSON.stringify(window.__coverage__))
+        )
+      );
+
+      await fs.promises.mkdir(istanbulTempDir, { recursive: true });
+      await context.exposeFunction(
+        'collectIstanbulCoverage',
+        (coverageJSON?: string) => {
+          if (coverageJSON)
+            fs.writeFileSync(
+              path.join(
+                istanbulTempDir,
+                `playwright_coverage_${generateUUID()}.json`
+              ),
+              coverageJSON
+            );
+        }
+      );
+    }
+
+    await use(context);
+
+    if (enableCoverage) {
+      for (const page of context.pages()) {
+        await page.evaluate(() =>
+          // @ts-expect-error
+          window.collectIstanbulCoverage(JSON.stringify(window.__coverage__))
+        );
+      }
+    }
+  },
+});