refactor: move remaining McpContext getters (#2342)

Moves various getters to McpPage.
2026-09-14 19:45:30 +08:00 · 2026-07-10 14:46:01 +02:00
parent eb049513d2
commit 58ba174273
20 changed files with 286 additions and 308 deletions
@@ -20,22 +20,15 @@ import type {
  DuplicateStringGroup,
 } from './HeapSnapshotManager.js';
 import {McpPage} from './McpPage.js';
-import {
-  NetworkCollector,
-  type ListenerMap,
-  type UncaughtError,
-} from './PageCollector.js';
+import {type UncaughtError} from './PageCollector.js';
 import {ServiceWorkerConsoleCollector} from './ServiceWorkerCollector.js';
 import {
  Locator,
-  PredefinedNetworkConditions,
  type Browser,
  type BrowserContext,
  type ConsoleMessage,
-  type HTTPRequest,
  type Page,
  type ScreenRecorder,
-  type Viewport,
  type Target,
  type Extension,
  type Root,
@@ -46,15 +39,8 @@ import {CLOSE_PAGE_ERROR} from './tools/ToolDefinition.js';
 import type {Context, SupportedExtensions} from './tools/ToolDefinition.js';
 import type {TraceResult} from './trace-processing/parse.js';
 import type {Logger} from './types.js';
-import type {
-  EmulationSettings,
-  GeolocationOptions,
-  ExtensionServiceWorker,
-} from './types.js';
+import type {ExtensionServiceWorker} from './types.js';
 import {getTempFilePath, resolveCanonicalPath} from './utils/files.js';
-import {type WithSymbolId, stableIdSymbol} from './utils/id.js';
-import {getNetworkMultiplierFromString} from './WaitForHelper.js';
-
 interface McpContextOptions {
  // Whether the DevTools windows are exposed as pages for debugging of DevTools.
  experimentalDevToolsDebugging: boolean;
@@ -72,9 +58,6 @@ interface McpContextOptions {
  allowUnrestrictedPaths?: boolean;
 }

-const DEFAULT_TIMEOUT = 5_000;
-const NAVIGATION_TIMEOUT = 10_000;
-
 export class McpContext implements Context {
  browser: Browser;
  logger: Logger;
@@ -305,12 +288,6 @@ export class McpContext implements Context {
    return page.devtoolsUniverse ?? null;
  }

-  getConsoleMessageStableId(
-    message: ConsoleMessage | Error | DevTools.AggregatedIssue | UncaughtError,
-  ): number {
-    return (message as WithSymbolId<typeof message>)[stableIdSymbol] ?? -1;
-  }
-
  async newPage(
    background?: boolean,
    isolatedContextName?: string,
@@ -343,136 +320,10 @@ export class McpContext implements Context {
    await page.pptrPage.close({runBeforeUnload: false});
  }

-  async restoreEmulation(page: McpPage) {
-    const currentSetting = page.emulationSettings;
-    await this.emulate(currentSetting, page);
-  }
-
  get #hasNetworkBlockOrAllowlist(): boolean {
    return !!(this.#options.allowList || this.#options.blocklist);
  }

-  async emulate(
-    options: {
-      networkConditions?: string;
-      cpuThrottlingRate?: number;
-      geolocation?: GeolocationOptions;
-      userAgent?: string;
-      colorScheme?: 'dark' | 'light' | 'auto';
-      viewport?: Viewport;
-      extraHttpHeaders?: Record<string, string> | undefined;
-    },
-    targetMcpPage?: McpPage,
-  ): Promise<void> {
-    const mcpPage = targetMcpPage ?? this.getSelectedMcpPage();
-    const page = mcpPage.pptrPage;
-    const newSettings: EmulationSettings = {...mcpPage.emulationSettings};
-
-    // Skip network emulation if blocklist/allowlist is configured, as it conflicts with blocking rules in Puppeteer.
-    if (this.#hasNetworkBlockOrAllowlist) {
-      if (options.networkConditions !== undefined) {
-        throw new Error(
-          'Network throttling is not supported when network blocking (allowlist/blocklist) is configured.',
-        );
-      }
-    } else if (!options.networkConditions) {
-      await page.emulateNetworkConditions(null);
-      delete newSettings.networkConditions;
-    } else if (options.networkConditions === 'Offline') {
-      await page.emulateNetworkConditions({
-        offline: true,
-        download: 0,
-        upload: 0,
-        latency: 0,
-      });
-      newSettings.networkConditions = 'Offline';
-    } else if (options.networkConditions in PredefinedNetworkConditions) {
-      const networkCondition =
-        PredefinedNetworkConditions[
-          options.networkConditions as keyof typeof PredefinedNetworkConditions
-        ];
-      await page.emulateNetworkConditions(networkCondition);
-      newSettings.networkConditions = options.networkConditions;
-    }
-
-    const secondarySession = this.getDevToolsUniverse(mcpPage)?.session;
-    if (!options.cpuThrottlingRate) {
-      await page.emulateCPUThrottling(1);
-      if (secondarySession) {
-        await secondarySession.send('Emulation.setCPUThrottlingRate', {
-          rate: 1,
-        });
-      }
-      delete newSettings.cpuThrottlingRate;
-    } else {
-      await page.emulateCPUThrottling(options.cpuThrottlingRate);
-      if (secondarySession) {
-        await secondarySession.send('Emulation.setCPUThrottlingRate', {
-          rate: options.cpuThrottlingRate,
-        });
-      }
-      newSettings.cpuThrottlingRate = options.cpuThrottlingRate;
-    }
-
-    if (!options.geolocation) {
-      await page.setGeolocation({latitude: 0, longitude: 0});
-      delete newSettings.geolocation;
-    } else {
-      await page.setGeolocation(options.geolocation);
-      newSettings.geolocation = options.geolocation;
-    }
-
-    if (!options.userAgent) {
-      await page.setUserAgent({userAgent: undefined});
-      delete newSettings.userAgent;
-    } else {
-      await page.setUserAgent({userAgent: options.userAgent});
-      newSettings.userAgent = options.userAgent;
-    }
-
-    if (!options.colorScheme || options.colorScheme === 'auto') {
-      await page.emulateMediaFeatures([
-        {name: 'prefers-color-scheme', value: ''},
-      ]);
-      delete newSettings.colorScheme;
-    } else {
-      await page.emulateMediaFeatures([
-        {name: 'prefers-color-scheme', value: options.colorScheme},
-      ]);
-      newSettings.colorScheme = options.colorScheme;
-    }
-
-    if (!options.viewport) {
-      delete newSettings.viewport;
-    } else {
-      const defaults = {
-        deviceScaleFactor: 1,
-        isMobile: false,
-        hasTouch: false,
-        isLandscape: false,
-      };
-      newSettings.viewport = {...defaults, ...options.viewport};
-    }
-
-    if (options.extraHttpHeaders !== undefined) {
-      await page.setExtraHTTPHeaders(options.extraHttpHeaders);
-      newSettings.extraHttpHeaders = options.extraHttpHeaders;
-      if (Object.keys(options.extraHttpHeaders).length === 0) {
-        delete newSettings.extraHttpHeaders;
-      }
-    }
-
-    mcpPage.emulationSettings = Object.keys(newSettings).length
-      ? newSettings
-      : {};
-
-    this.#updateSelectedPageTimeouts();
-
-    // This should happen after updating the page timeouts.
-    // Setting the viewport can trigger a reload which we don't want to timeout.
-    await page.setViewport(newSettings.viewport ?? null);
-  }
-
  setIsRunningPerformanceTrace(x: boolean): void {
    this.#isRunningTrace = x;
  }
@@ -526,7 +377,7 @@ export class McpContext implements Context {

  selectPage(newPage: McpPage): void {
    this.#selectedPage = newPage;
-    this.#updateSelectedPageTimeouts();
+    newPage.updateTimeouts();
  }

  /**
@@ -539,36 +390,6 @@ export class McpContext implements Context {
    return this.#selectedPageFallback;
  }

-  #updateSelectedPageTimeouts() {
-    const page = this.getSelectedMcpPage();
-    // For waiters 5sec timeout should be sufficient.
-    // Increased in case we throttle the CPU
-    const cpuMultiplier = page.cpuThrottlingRate;
-    page.pptrPage.setDefaultTimeout(DEFAULT_TIMEOUT * cpuMultiplier);
-    // 10sec should be enough for the load event to be emitted during
-    // navigations.
-    // Increased in case we throttle the network requests or the CPU
-    const networkMultiplier = getNetworkMultiplierFromString(
-      page.networkConditions,
-    );
-    page.pptrPage.setDefaultNavigationTimeout(
-      NAVIGATION_TIMEOUT * networkMultiplier * cpuMultiplier,
-    );
-  }
-
-  // Linear scan over per-page snapshots. The page count is small (typically
-  // 2-10) so a reverse index isn't worthwhile given the uid-reuse lifecycle
-  // complexity it would introduce.
-  getAXNodeByUid(uid: string) {
-    for (const mcpPage of this.#mcpPages.values()) {
-      const node = mcpPage.textSnapshot?.idToNode.get(uid);
-      if (node) {
-        return node;
-      }
-    }
-    return undefined;
-  }
-
  /**
   * Creates a snapshot of the extension service workers.
   */
@@ -613,7 +434,10 @@ export class McpContext implements Context {
  #createMcpPage(page: Page): McpPage {
    let mcpPage = this.#mcpPages.get(page);
    if (!mcpPage) {
-      mcpPage = new McpPage(page, this.#nextPageId++);
+      mcpPage = new McpPage(page, this.#nextPageId++, {
+        locatorClass: this.#locatorClass,
+        hasNetworkBlockOrAllowlist: this.#hasNetworkBlockOrAllowlist,
+      });
      this.#mcpPages.set(page, mcpPage);
      void mcpPage.init();
    }
@@ -816,58 +640,6 @@ export class McpContext implements Context {
    return this.#traceResults;
  }

-  getNetworkRequestStableId(request: HTTPRequest): number {
-    return (request as WithSymbolId<typeof request>)[stableIdSymbol] ?? -1;
-  }
-
-  waitForTextOnPage(
-    text: string[],
-    timeout?: number,
-    mcpPage?: McpPage,
-  ): Promise<Element> {
-    const page = mcpPage
-      ? mcpPage.pptrPage
-      : this.getSelectedMcpPage().pptrPage;
-    const frames = page.frames();
-
-    let locator = this.#locatorClass.race(
-      frames.flatMap(frame =>
-        text.flatMap(value => [
-          frame.locator(`aria/${value}`),
-          frame.locator(`text/${value}`),
-        ]),
-      ),
-    );
-
-    if (timeout) {
-      locator = locator.setTimeout(timeout);
-    }
-
-    return locator.wait();
-  }
-
-  /**
-   * We need to ignore favicon request as they make our test flaky
-   */
-  async setUpNetworkCollectorForTesting() {
-    for (const mcpPage of this.getPages()) {
-      mcpPage.networkCollector.dispose();
-      mcpPage.networkCollector = new NetworkCollector(
-        mcpPage.pptrPage,
-        collect => {
-          return {
-            request: req => {
-              if (req.url().includes('favicon.ico')) {
-                return;
-              }
-              collect(req);
-            },
-          } as ListenerMap;
-        },
-      );
-    }
-  }
-
  async installExtension(extensionPath: string): Promise<string> {
    const id = await this.browser.installExtension(extensionPath);
    return id;
@@ -16,19 +16,23 @@ import {
  type UncaughtError,
 } from './PageCollector.js';
 import {TextSnapshot} from './TextSnapshot.js';
-import type {
-  Dialog,
-  ElementHandle,
-  Viewport,
-  WebMCPTool,
-  Protocol,
-  Page,
-  ConsoleMessage,
-  HTTPRequest,
-  DevTools,
+import type {Locator} from './third_party/index.js';
+import {
+  PredefinedNetworkConditions,
+  type Dialog,
+  type ElementHandle,
+  type Viewport,
+  type WebMCPTool,
+  type Protocol,
+  type Page,
+  type ConsoleMessage,
+  type HTTPRequest,
+  type DevTools,
 } from './third_party/index.js';
 import {takeSnapshot} from './tools/snapshot.js';
 import type {ToolGroups} from './tools/thirdPartyDeveloper.js';
+const DEFAULT_TIMEOUT = 5_000;
+const NAVIGATION_TIMEOUT = 10_000;
 import type {
  ContextPage,
  DevToolsData,
@@ -39,6 +43,7 @@ import type {
  GeolocationOptions,
  TextSnapshotNode,
 } from './types.js';
+import {type WithSymbolId, stableIdSymbol} from './utils/id.js';
 import {
  getNetworkMultiplierFromString,
  WaitForHelper,
@@ -80,7 +85,19 @@ export class McpPage implements ContextPage {
  networkCollector: NetworkCollector;
  consoleCollector: ConsoleCollector;

-  constructor(page: Page, id: number) {
+  #hasNetworkBlockOrAllowlist: boolean;
+  #locatorClass: typeof Locator;
+
+  constructor(
+    page: Page,
+    id: number,
+    options: {
+      hasNetworkBlockOrAllowlist: boolean;
+      locatorClass: typeof Locator;
+    },
+  ) {
+    this.#hasNetworkBlockOrAllowlist = options.hasNetworkBlockOrAllowlist;
+    this.#locatorClass = options.locatorClass;
    this.pptrPage = page;
    this.id = id;
    this.#dialogHandler = (dialog: Dialog): void => {
@@ -494,4 +511,186 @@ export class McpPage implements ContextPage {
    }
    return {};
  }
+
+  getConsoleMessageStableId(
+    message: ConsoleMessage | Error | DevTools.AggregatedIssue | UncaughtError,
+  ): number {
+    return (message as WithSymbolId<typeof message>)[stableIdSymbol] ?? -1;
+  }
+
+  getNetworkRequestStableId(request: HTTPRequest): number {
+    return (request as WithSymbolId<typeof request>)[stableIdSymbol] ?? -1;
+  }
+
+  async restoreEmulation() {
+    const currentSetting = this.emulationSettings;
+    await this.emulate(currentSetting);
+  }
+
+  async emulate(options: {
+    networkConditions?: string;
+    cpuThrottlingRate?: number;
+    geolocation?: GeolocationOptions;
+    userAgent?: string;
+    colorScheme?: 'dark' | 'light' | 'auto';
+    viewport?: Viewport;
+    extraHttpHeaders?: Record<string, string> | undefined;
+  }): Promise<void> {
+    const page = this.pptrPage;
+    const newSettings: EmulationSettings = {...this.emulationSettings};
+
+    // Skip network emulation if blocklist/allowlist is configured, as it conflicts with blocking rules in Puppeteer.
+    if (this.#hasNetworkBlockOrAllowlist) {
+      if (options.networkConditions !== undefined) {
+        throw new Error(
+          'Network throttling is not supported when network blocking (allowlist/blocklist) is configured.',
+        );
+      }
+    } else if (!options.networkConditions) {
+      await page.emulateNetworkConditions(null);
+      delete newSettings.networkConditions;
+    } else if (options.networkConditions === 'Offline') {
+      await page.emulateNetworkConditions({
+        offline: true,
+        download: 0,
+        upload: 0,
+        latency: 0,
+      });
+      newSettings.networkConditions = 'Offline';
+    } else if (options.networkConditions in PredefinedNetworkConditions) {
+      const networkCondition =
+        PredefinedNetworkConditions[
+          options.networkConditions as keyof typeof PredefinedNetworkConditions
+        ];
+      await page.emulateNetworkConditions(networkCondition);
+      newSettings.networkConditions = options.networkConditions;
+    }
+
+    const secondarySession = this.devtoolsUniverse?.session;
+    if (!options.cpuThrottlingRate) {
+      await page.emulateCPUThrottling(1);
+      if (secondarySession) {
+        await secondarySession.send('Emulation.setCPUThrottlingRate', {
+          rate: 1,
+        });
+      }
+      delete newSettings.cpuThrottlingRate;
+    } else {
+      await page.emulateCPUThrottling(options.cpuThrottlingRate);
+      if (secondarySession) {
+        await secondarySession.send('Emulation.setCPUThrottlingRate', {
+          rate: options.cpuThrottlingRate,
+        });
+      }
+      newSettings.cpuThrottlingRate = options.cpuThrottlingRate;
+    }
+
+    if (!options.geolocation) {
+      await page.setGeolocation({latitude: 0, longitude: 0});
+      delete newSettings.geolocation;
+    } else {
+      await page.setGeolocation(options.geolocation);
+      newSettings.geolocation = options.geolocation;
+    }
+
+    if (!options.userAgent) {
+      await page.setUserAgent({userAgent: undefined});
+      delete newSettings.userAgent;
+    } else {
+      await page.setUserAgent({userAgent: options.userAgent});
+      newSettings.userAgent = options.userAgent;
+    }
+
+    if (!options.colorScheme || options.colorScheme === 'auto') {
+      await page.emulateMediaFeatures([
+        {name: 'prefers-color-scheme', value: ''},
+      ]);
+      delete newSettings.colorScheme;
+    } else {
+      await page.emulateMediaFeatures([
+        {name: 'prefers-color-scheme', value: options.colorScheme},
+      ]);
+      newSettings.colorScheme = options.colorScheme;
+    }
+
+    if (!options.viewport) {
+      delete newSettings.viewport;
+    } else {
+      const defaults = {
+        deviceScaleFactor: 1,
+        isMobile: false,
+        hasTouch: false,
+        isLandscape: false,
+      };
+      newSettings.viewport = {...defaults, ...options.viewport};
+    }
+
+    if (options.extraHttpHeaders !== undefined) {
+      await page.setExtraHTTPHeaders(options.extraHttpHeaders);
+      newSettings.extraHttpHeaders = options.extraHttpHeaders;
+      if (Object.keys(options.extraHttpHeaders).length === 0) {
+        delete newSettings.extraHttpHeaders;
+      }
+    }
+
+    this.emulationSettings = Object.keys(newSettings).length ? newSettings : {};
+
+    this.updateTimeouts();
+
+    // This should happen after updating the page timeouts.
+    // Setting the viewport can trigger a reload which we don't want to timeout.
+    await page.setViewport(newSettings.viewport ?? null);
+  }
+
+  updateTimeouts() {
+    // For waiters 5sec timeout should be sufficient.
+    // Increased in case we throttle the CPU
+    const cpuMultiplier = this.cpuThrottlingRate;
+    this.pptrPage.setDefaultTimeout(DEFAULT_TIMEOUT * cpuMultiplier);
+    // 10sec should be enough for the load event to be emitted during
+    // navigations.
+    // Increased in case we throttle the network requests or the CPU
+    const networkMultiplier = getNetworkMultiplierFromString(
+      this.networkConditions,
+    );
+    this.pptrPage.setDefaultNavigationTimeout(
+      NAVIGATION_TIMEOUT * networkMultiplier * cpuMultiplier,
+    );
+  }
+
+  waitForTextOnPage(text: string[], timeout?: number): Promise<Element> {
+    const frames = this.pptrPage.frames();
+
+    let locator = this.#locatorClass.race(
+      frames.flatMap(frame =>
+        text.flatMap(value => [
+          frame.locator(`aria/${value}`),
+          frame.locator(`text/${value}`),
+        ]),
+      ),
+    );
+
+    if (timeout) {
+      locator = locator.setTimeout(timeout);
+    }
+
+    return locator.wait();
+  }
+
+  /**
+   * We need to ignore favicon request as they make our test flaky
+   */
+  async setUpNetworkCollectorForTesting() {
+    this.networkCollector.dispose();
+    this.networkCollector = new NetworkCollector(this.pptrPage, collect => {
+      return {
+        request: req => {
+          if (req.url().includes('favicon.ico')) {
+            return;
+          }
+          collect(req);
+        },
+      } as ListenerMap;
+    });
+  }
 }
@@ -615,7 +615,8 @@ export class McpResponse implements Response {
      );
      const formatter = await NetworkFormatter.from(request, {
        requestId: this.#attachedNetworkRequestId,
-        requestIdResolver: req => context.getNetworkRequestStableId(req),
+        requestIdResolver: req =>
+          context.getSelectedMcpPage().getNetworkRequestStableId(req),
        fetchData: true,
        requestFilePath: this.#attachedNetworkRequestOptions?.requestFilePath,
        responseFilePath: this.#attachedNetworkRequestOptions?.responseFilePath,
@@ -724,8 +725,9 @@ export class McpResponse implements Response {
        await Promise.all(
          messages.map(
            async (item): Promise<ConsoleFormatter | IssueFormatter | null> => {
-              const consoleMessageStableId =
-                context.getConsoleMessageStableId(item);
+              const consoleMessageStableId = context
+                .getSelectedMcpPage()
+                .getConsoleMessageStableId(item);
              if ('args' in item || item instanceof UncaughtError) {
                const consoleMessage = item as ConsoleMessage | UncaughtError;
                const devTools = page
@@ -777,9 +779,13 @@ export class McpResponse implements Response {
        networkRequests = await Promise.all(
          requests.map(request =>
            NetworkFormatter.from(request, {
-              requestId: context.getNetworkRequestStableId(request),
+              requestId: context
+                .getSelectedMcpPage()
+                .getNetworkRequestStableId(request),
              selectedInDevToolsUI:
-                context.getNetworkRequestStableId(request) ===
+                context
+                  .getSelectedMcpPage()
+                  .getNetworkRequestStableId(request) ===
                this.#networkRequestsOptions?.networkRequestIdInDevToolsUI,
              fetchData: false,
              saveFile: (data, filename, extension) =>
@@ -206,18 +206,6 @@ export type Context = Readonly<{
  ): Promise<ContextPage>;
  closePage(pageId: number): Promise<void>;
  selectPage(page: ContextPage): void;
-  restoreEmulation(page: ContextPage): Promise<void>;
-  emulate(
-    options: {
-      networkConditions?: string;
-      cpuThrottlingRate?: number;
-      geolocation?: GeolocationOptions;
-      userAgent?: string;
-      colorScheme?: 'dark' | 'light' | 'auto';
-      viewport?: Viewport;
-    },
-    mcpPage?: ContextPage,
-  ): Promise<void>;
  saveTemporaryFile(
    data: Uint8Array<ArrayBufferLike>,
    filename: string,
@@ -227,11 +215,6 @@ export type Context = Readonly<{
    clientProvidedFilePath: string,
    extension: SupportedExtensions,
  ): Promise<{filename: string}>;
-  waitForTextOnPage(
-    text: string[],
-    timeout?: number,
-    mcpPage?: ContextPage,
-  ): Promise<Element>;

  getScreenRecorder(): {recorder: ScreenRecorder; filePath: string} | null;
  setScreenRecorder(
@@ -330,6 +313,16 @@ export type ContextPage = Readonly<{
    response: Response,
  ): Promise<void>;
  getDevToolsData(): Promise<DevToolsData>;
+  restoreEmulation(): Promise<void>;
+  emulate(options: {
+    networkConditions?: string;
+    cpuThrottlingRate?: number;
+    geolocation?: GeolocationOptions;
+    userAgent?: string;
+    colorScheme?: 'dark' | 'light' | 'auto';
+    viewport?: Viewport;
+  }): Promise<void>;
+  waitForTextOnPage(text: string[], timeout?: number): Promise<Element>;
 }>;

 export function defineTool<Schema extends zod.ZodRawShape>(
@@ -101,9 +101,9 @@ export const emulate = definePageTool({
  },
  blockedByDialog: true,
  verifyFilesSchema: [],
-  handler: async (request, response, context) => {
+  handler: async (request, response) => {
    const page = request.page;
-    await context.emulate(request.params, page);
+    await page.emulate(request.params);
    response.appendResponseLine('Emulation configured successfully');
  },
 });
@@ -60,7 +60,7 @@ export const listExtensions = defineTool({
  schema: {},
  blockedByDialog: false,
  verifyFilesSchema: [],
-  handler: async (_request, response, _context) => {
+  handler: async (_request, response) => {
    response.setListExtensions();
  },
 });
@@ -261,7 +261,7 @@ async function fillFormElement(
 ) {
  const handle = await page.getElementByUid(uid);
  try {
-    const aXNode = context.getAXNodeByUid(uid);
+    const aXNode = page.getAXNodeByUid(uid);
    // We assume that combobox needs to be handled as select if it has
    // role='combobox' and option children.
    if (aXNode && aXNode.role === 'combobox' && hasOptionChildren(aXNode)) {
@@ -469,7 +469,7 @@ export const uploadFile = definePageTool({
  },
  blockedByDialog: true,
  verifyFilesSchema: ['filePath'],
-  handler: async (request, response, _context) => {
+  handler: async (request, response) => {
    const {uid, filePath} = request.params;
    const handle = (await request.page.getElementByUid(
      uid,
@@ -103,7 +103,7 @@ export const lighthouseAudit = definePageTool({
        throw new Error('Lighthouse audit failed.');
      }
    } finally {
-      await context.restoreEmulation(page);
+      await page.restoreEmulation();
    }

    const lhr = result.lhr;
@@ -307,7 +307,7 @@ export const resizePage = definePageTool({
  },
  blockedByDialog: false,
  verifyFilesSchema: [],
-  handler: async (request, response, _context) => {
+  handler: async (request, response) => {
    const page = request.page;

    try {
@@ -353,7 +353,7 @@ export const handleDialog = definePageTool({
  },
  blockedByDialog: false,
  verifyFilesSchema: [],
-  handler: async (request, response, _context) => {
+  handler: async (request, response) => {
    const page = request.page;
    const dialog = page.getDialog();
    if (!dialog) {
@@ -61,13 +61,9 @@ export const waitFor = definePageTool({
  },
  blockedByDialog: true,
  verifyFilesSchema: [],
-  handler: async (request, response, context) => {
+  handler: async (request, response) => {
    const page = request.page;
-    await context.waitForTextOnPage(
-      request.params.text,
-      request.params.timeout,
-      page,
-    );
+    await page.waitForTextOnPage(request.params.text, request.params.timeout);

    response.appendResponseLine(
      `Element matching one of ${JSON.stringify(request.params.text)} found.`,
@@ -58,7 +58,7 @@ third-party developer tools with additional functionality.`,
  schema: {},
  blockedByDialog: false,
  verifyFilesSchema: [],
-  handler: async (_request, response, _context) => {
+  handler: async (_request, response) => {
    response.setListThirdPartyDeveloperTools();
  },
 });
@@ -19,7 +19,7 @@ export const listWebMcpTools = definePageTool({
  schema: {},
  blockedByDialog: false,
  verifyFilesSchema: [],
-  handler: async (_request, response, _context) => {
+  handler: async (_request, response) => {
    response.setListWebMcpTools();
  },
 });
@@ -56,7 +56,7 @@ describe('McpContext', () => {
    await withMcpContext(async (_response, context) => {
      const page = await context.newPage();
      const timeoutBefore = page.pptrPage.getDefaultTimeout();
-      await context.emulate({cpuThrottlingRate: 2});
+      await context.getSelectedMcpPage().emulate({cpuThrottlingRate: 2});
      const timeoutAfter = page.pptrPage.getDefaultTimeout();
      assert(timeoutBefore < timeoutAfter, 'Timeout was less then expected');
    });
@@ -66,7 +66,9 @@ describe('McpContext', () => {
    await withMcpContext(async (_response, context) => {
      const page = await context.newPage();
      const timeoutBefore = page.pptrPage.getDefaultNavigationTimeout();
-      await context.emulate({networkConditions: 'Slow 3G'});
+      await context
+        .getSelectedMcpPage()
+        .emulate({networkConditions: 'Slow 3G'});
      const timeoutAfter = page.pptrPage.getDefaultNavigationTimeout();
      assert(timeoutBefore < timeoutAfter, 'Timeout was less then expected');
    });
@@ -76,7 +78,7 @@ describe('McpContext', () => {
    await withMcpContext(async (_response, context) => {
      const page = await context.newPage();

-      await context.emulate({
+      await context.getSelectedMcpPage().emulate({
        cpuThrottlingRate: 2,
        networkConditions: 'Slow 3G',
      });
@@ -133,7 +135,7 @@ describe('McpContext', () => {

      // Capture a uid from page1's snapshot (snapshotId=1, button is node 1)
      const page1Uid = '1_1';
-      const page1Node = context.getAXNodeByUid(page1Uid);
+      const page1Node = page1.getAXNodeByUid(page1Uid);
      assert.ok(page1Node, 'uid should resolve from page1 snapshot');

      // Page 2: new page, set content, snapshot
@@ -145,7 +147,7 @@ describe('McpContext', () => {
      });

      // Page 2 is now selected. Page 1's uid should still resolve.
-      const node = context.getAXNodeByUid(page1Uid);
+      const node = page1.getAXNodeByUid(page1Uid);
      assert.ok(node, 'page1 uid should still resolve after page2 snapshot');
      assert.strictEqual(node?.name, 'Page1 Button');

@@ -230,7 +232,9 @@ describe('McpContext', () => {
      sinon
        .stub(context.getSelectedMcpPage(), 'getNetworkRequests')
        .returns([mockRequest]);
-      sinon.stub(context, 'getNetworkRequestStableId').returns(123);
+      sinon
+        .stub(context.getSelectedMcpPage(), 'getNetworkRequestStableId')
+        .returns(123);

      response.setIncludeNetworkRequests(true);
      const result = await response.handle('test', context);
@@ -248,7 +252,9 @@ describe('McpContext', () => {
      sinon
        .stub(context.getSelectedMcpPage(), 'getNetworkRequestById')
        .returns(mockRequest);
-      sinon.stub(context, 'getNetworkRequestStableId').returns(456);
+      sinon
+        .stub(context.getSelectedMcpPage(), 'getNetworkRequestStableId')
+        .returns(456);

      response.attachNetworkRequest(456);
      const result = await response.handle('test', context);
@@ -274,7 +280,9 @@ describe('McpContext', () => {
      sinon
        .stub(context.getSelectedMcpPage(), 'getNetworkRequestById')
        .returns(mockRequest);
-      sinon.stub(context, 'getNetworkRequestStableId').returns(789);
+      sinon
+        .stub(context.getSelectedMcpPage(), 'getNetworkRequestStableId')
+        .returns(789);

      // Use os.tmpdir() so validatePath passes on all platforms (macOS tmpdir
      // is /var/folders/..., not /tmp, so hardcoded /tmp paths are rejected).
@@ -296,7 +296,9 @@ describe('McpResponse', () => {

  it('adds throttling setting when it is not null', async t => {
    await withMcpContext(async (response, context) => {
-      await context.emulate({networkConditions: 'Slow 3G'});
+      await context
+        .getSelectedMcpPage()
+        .emulate({networkConditions: 'Slow 3G'});
      const {content, structuredContent} = await response.handle(
        'test',
        context,
@@ -315,7 +317,7 @@ describe('McpResponse', () => {
        'test',
        context,
      );
-      await context.emulate({});
+      await context.getSelectedMcpPage().emulate({});
      t.assert.snapshot(getTextContent(content[0]));
      t.assert.snapshot(
        JSON.stringify(stabilizeStructuredContent(structuredContent), null, 2),
@@ -341,7 +343,7 @@ describe('McpResponse', () => {

  it('adds cpu throttling setting when it is over 1', async t => {
    await withMcpContext(async (response, context) => {
-      await context.emulate({cpuThrottlingRate: 4});
+      await context.getSelectedMcpPage().emulate({cpuThrottlingRate: 4});
      const {content, structuredContent} = await response.handle(
        'test',
        context,
@@ -355,7 +357,7 @@ describe('McpResponse', () => {

  it('does not include cpu throttling setting when it is 1', async t => {
    await withMcpContext(async (response, context) => {
-      await context.emulate({cpuThrottlingRate: 1});
+      await context.getSelectedMcpPage().emulate({cpuThrottlingRate: 1});
      const {content, structuredContent} = await response.handle(
        'test',
        context,
@@ -369,7 +371,7 @@ describe('McpResponse', () => {

  it('adds viewport emulation setting when it is set', async t => {
    await withMcpContext(async (response, context) => {
-      await context.emulate({
+      await context.getSelectedMcpPage().emulate({
        viewport: {width: 400, height: 400, deviceScaleFactor: 1},
      });
      const {content, structuredContent} = await response.handle(
@@ -385,7 +387,7 @@ describe('McpResponse', () => {

  it('adds userAgent emulation setting when it is set', async t => {
    await withMcpContext(async (response, context) => {
-      await context.emulate({userAgent: 'MyUA'});
+      await context.getSelectedMcpPage().emulate({userAgent: 'MyUA'});
      const {content, structuredContent} = await response.handle(
        'test',
        context,
@@ -399,7 +401,7 @@ describe('McpResponse', () => {

  it('adds color scheme emulation setting when it is set', async t => {
    await withMcpContext(async (response, context) => {
-      await context.emulate({colorScheme: 'dark'});
+      await context.getSelectedMcpPage().emulate({colorScheme: 'dark'});
      const {content, structuredContent} = await response.handle(
        'test',
        context,
@@ -412,7 +412,9 @@ describe('console', () => {
            }
          }
          assert.ok(issueMsg);
-          const id = context.getConsoleMessageStableId(issueMsg);
+          const id = context
+            .getSelectedMcpPage()
+            .getConsoleMessageStableId(issueMsg);
          assert.ok(id);
          await listConsoleMessages().handler(
            {params: {types: ['issue']}, page: context.getSelectedMcpPage()},
@@ -241,7 +241,7 @@ describe('emulation', () => {

    it('disables cpu throttling', async () => {
      await withMcpContext(async (response, context) => {
-        await context.emulate({
+        await context.getSelectedMcpPage().emulate({
          cpuThrottlingRate: 4,
        });
        await emulate.handler(
@@ -58,7 +58,7 @@ describe('lighthouse', () => {
      await withMcpContext(async (response, context) => {
        const page = context.getSelectedMcpPage().pptrPage;
        await page.goto(server.getRoute('/test-mobile'));
-        await context.emulate({
+        await context.getSelectedMcpPage().emulate({
          viewport: {
            width: 400,
            height: 400,
@@ -40,7 +40,7 @@ describe('network', () => {
      server.addHtmlRoute('/three', html`<main>Third</main>`);

      await withMcpContext(async (response, context) => {
-        await context.setUpNetworkCollectorForTesting();
+        await context.getSelectedMcpPage().setUpNetworkCollectorForTesting();
        const page = context.getSelectedMcpPage().pptrPage;
        await page.goto(server.getRoute('/one'));
        await page.goto(server.getRoute('/two'));
@@ -67,7 +67,7 @@ describe('network', () => {
      server.addHtmlRoute('/three', html`<main>Third</main>`);

      await withMcpContext(async (response, context) => {
-        await context.setUpNetworkCollectorForTesting();
+        await context.getSelectedMcpPage().setUpNetworkCollectorForTesting();
        const page = context.getSelectedMcpPage().pptrPage;
        await page.goto(server.getRoute('/one'));
        await page.goto(server.getRoute('/two'));
@@ -110,7 +110,7 @@ describe('network', () => {
      );

      await withMcpContext(async (response, context) => {
-        await context.setUpNetworkCollectorForTesting();
+        await context.getSelectedMcpPage().setUpNetworkCollectorForTesting();
        const page = context.getSelectedMcpPage().pptrPage;
        await page.goto(server.getRoute('/redirect'), {
          waitUntil: 'networkidle0',
@@ -164,7 +164,7 @@ describe('network', () => {
      server.addHtmlRoute('/three', html`<main>Third</main>`);

      await withMcpContext(async (response, context) => {
-        await context.setUpNetworkCollectorForTesting();
+        await context.getSelectedMcpPage().setUpNetworkCollectorForTesting();
        const page = context.getSelectedMcpPage().pptrPage;
        await page.goto(server.getRoute('/one'));
        await page.goto(server.getRoute('/two'));
@@ -171,7 +171,7 @@ describe('pages', () => {
            `chrome-extension://${extensionId}/sidepanel.html`,
          );

-          await context.waitForTextOnPage(['Side Panel']);
+          await context.getSelectedMcpPage().waitForTextOnPage(['Side Panel']);

          // Wait for service worker used in the snapshot.
          await context.browser.waitForTarget(
@@ -449,7 +449,7 @@ describe('performance', () => {
        sinon.stub(selectedPage.tracing, 'stop').resolves(modifiedData);

        // Emulate mobile
-        await context.emulate({
+        await context.getSelectedMcpPage().emulate({
          viewport: {
            width: 375,
            height: 667,