Reference files in Playwright more reliably (#32935)

Without assuming the cwd

apps/web/playwright/sample-files/index.ts

@@ -0,0 +1,32 @@
+/*
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+import { readFile } from "node:fs/promises";
+import { readFileSync } from "node:fs";
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+
+export function getSampleFilePath(file: string): string {
+    return join(__dirname, file);
+}
+
+export function readSampleFile(file: string, encoding: null): Promise<NonSharedBuffer>;
+export function readSampleFile(file: string, encoding?: BufferEncoding): Promise<string>;
+export function readSampleFile(
+    file: string,
+    encoding: BufferEncoding | null = "utf-8",
+): Promise<NonSharedBuffer | string> {
+    return readFile(getSampleFilePath(file), encoding);
+}
+
+export function readSampleFileSync(file: string, encoding: null): NonSharedBuffer;
+export function readSampleFileSync(file: string, encoding?: BufferEncoding): string;
+export function readSampleFileSync(file: string, encoding: BufferEncoding | null = "utf-8"): NonSharedBuffer | string {
+    return readFileSync(getSampleFilePath(file), encoding);
+}