playwright-mcp/src/pageSnapshot.ts

/**
 * Copyright (c) Microsoft Corporation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import * as playwright from 'playwright';
import { callOnPageNoTrace } from './tools/utils.js';

type PageEx = playwright.Page & {
  _snapshotForAI: () => Promise<string>;
};

export class PageSnapshot {
  private _page: playwright.Page;
  private _text!: string;

  constructor(page: playwright.Page) {
    this._page = page;
  }

  static async create(page: playwright.Page): Promise<PageSnapshot> {
    const snapshot = new PageSnapshot(page);
    await snapshot._build();
    return snapshot;
  }

  text(): string {
    return this._text;
  }

  private async _build() {
    const snapshot = await callOnPageNoTrace(this._page, page => (page as PageEx)._snapshotForAI());
    this._text = [
      `- Page Snapshot`,
      '```yaml',
      snapshot,
      '```',
    ].join('\n');
  }

  refLocator(ref: string): playwright.Locator {
    return this._page.locator(`aria-ref=${ref}`);
  }
}