fix(pages): revert reporting the page size after resize_page (#3308)

This reverts commit f0030564a3 (#3132).

`McpPage.resize()` read `Page.getLayoutMetrics` from the target page
after the resize. Chrome does not lay out a background tab again until
the tab is visible. Thus, for a background tab, `resize_page` reported
the old page size (for example `Requested 1100x750, page is 1504x836`),
although the window had the requested size.

The window bounds (`Browser.getWindowBounds`) cannot replace the layout
metrics. They give the outer window size, which includes the tab strip
and the toolbar, not the page size.

`resize_page` again prints no page size. #2998 is open again.

Fixes #3306

docs/tool-reference.md

@@ -298,7 +298,7 @@
 
 ### `resize_page`
 
-**Description:** Resizes the page's window so that the page has specified dimension. If the browser clamps the window size, the actual page dimensions are reported.
+**Description:** Resizes the page's window so that the page has specified dimension
 
 **Parameters:**
 

src/McpPage.ts

@@ -1439,45 +1439,6 @@ export class McpPage implements ContextPage {
     });
   }
 
-  async resize(
-    width: number,
-    height: number,
-  ): Promise<{width: number; height: number} | undefined> {
-    try {
-      const browser = this.pptrPage.browser();
-      const windowId = await this.pptrPage.windowId();
-      const bounds = await browser.getWindowBounds(windowId);
-
-      if (bounds.windowState === 'fullscreen') {
-        // Have to call this twice on Ubuntu when the window is in fullscreen mode.
-        await browser.setWindowBounds(windowId, {windowState: 'normal'});
-        await browser.setWindowBounds(windowId, {windowState: 'normal'});
-      } else if (bounds.windowState !== 'normal') {
-        await browser.setWindowBounds(windowId, {windowState: 'normal'});
-      }
-    } catch {
-      // Window APIs are not supported on all platforms
-    }
-    await this.pptrPage.resize({
-      contentWidth: width,
-      contentHeight: height,
-    });
-
-    if (this.getDialog()) {
-      return undefined;
-    }
-
-    // @ts-expect-error internal API
-    const client = this.pptrPage._client();
-    const metrics: Protocol.Page.GetLayoutMetricsResponse = await client.send(
-      'Page.getLayoutMetrics',
-    );
-    return {
-      width: metrics.cssLayoutViewport.clientWidth,
-      height: metrics.cssLayoutViewport.clientHeight,
-    };
-  }
-
   lighthouseNavigation(flags?: Flags): Promise<RunnerResult | undefined> {
     return lighthouseNavigation(this.pptrPage, this.pptrPage.url(), {
       flags,

src/config/cli-options.ts

@@ -1754,7 +1754,7 @@ export const commands: Commands = {
   },
   resize_page: {
     description:
-      "Resizes the page's window so that the page has specified dimension. If the browser clamps the window size, the actual page dimensions are reported.",
+      "Resizes the page's window so that the page has specified dimension",
     category: 'Emulation',
     args: {
       pageId: {

src/tools/ToolDefinition.ts

@@ -529,10 +529,6 @@ export type ContextPage = Readonly<{
     text: string[],
     options?: {timeout?: number; visible?: boolean},
   ): Promise<Element>;
-  resize(
-    width: number,
-    height: number,
-  ): Promise<{width: number; height: number} | undefined>;
   getDevToolsPage(): Promise<Page | undefined>;
   openDevTools(): Promise<Page | undefined>;
   ensureDevToolsCommentBridge(

src/tools/pages.ts

@@ -355,7 +355,7 @@ export const navigatePage: PageToolFactory = definePageTool(
 
 export const resizePage: PageToolFactory = definePageTool(() => ({
   name: 'resize_page',
-  description: `Resizes the page's window so that the page has specified dimension. If the browser clamps the window size, the actual page dimensions are reported.`,
+  description: `Resizes the page's window so that the page has specified dimension`,
   annotations: {
     category: ToolCategory.EMULATION,
     readOnlyHint: false,
@@ -369,17 +369,27 @@ export const resizePage: PageToolFactory = definePageTool(() => ({
   verifyFilesSchema: {},
   handler: async (request, response) => {
     const page = request.page;
-    const {width, height} = request.params;
 
-    const actualSize = await page.resize(width, height);
-    if (
-      actualSize &&
-      (actualSize.width !== width || actualSize.height !== height)
-    ) {
-      response.appendResponseLine(
-        `Requested ${width}x${height}, page is ${actualSize.width}x${actualSize.height}`,
-      );
+    try {
+      const browser = page.pptrPage.browser();
+      const windowId = await page.pptrPage.windowId();
+
+      const bounds = await browser.getWindowBounds(windowId);
+
+      if (bounds.windowState === 'fullscreen') {
+        // Have to call this twice on Ubuntu when the window is in fullscreen mode.
+        await browser.setWindowBounds(windowId, {windowState: 'normal'});
+        await browser.setWindowBounds(windowId, {windowState: 'normal'});
+      } else if (bounds.windowState !== 'normal') {
+        await browser.setWindowBounds(windowId, {windowState: 'normal'});
+      }
+    } catch {
+      // Window APIs are not supported on all platforms
     }
+    await page.pptrPage.resize({
+      contentWidth: request.params.width,
+      contentHeight: request.params.height,
+    });
 
     response.setIncludePages(true);
   },

tests/McpPage.test.ts

@@ -26,7 +26,6 @@ import {
   createMockCDPSession,
   createMockDialog,
   createMockMcpResponse,
-  createMockPuppeteerBrowser,
   createMockPuppeteerPage,
   createMockPuppeteerTarget,
   createMockServerConfig,
@@ -2258,107 +2257,6 @@ describe('McpPage', () => {
     });
   });
 
-  describe('resize()', () => {
-    it('resizes the page and returns the resulting cssLayoutViewport dimensions', async () => {
-      const {mcpPage, pptrPage} = await createMcpPage();
-      const browser = createMockPuppeteerBrowser();
-      pptrPage.browser.returns(browser);
-      pptrPage.windowId.resolves('win-1');
-      browser.getWindowBounds.resolves({windowState: 'normal'});
-      pptrPage.cdpSession.send.withArgs('Page.getLayoutMetrics').resolves({
-        cssLayoutViewport: {
-          clientWidth: 500,
-          clientHeight: 232,
-          pageX: 0,
-          pageY: 0,
-        },
-      });
-
-      const actualSize = await mcpPage.resize(100, 100);
-
-      sinon.assert.notCalled(browser.setWindowBounds);
-      sinon.assert.calledOnceWithExactly(pptrPage.resize, {
-        contentWidth: 100,
-        contentHeight: 100,
-      });
-      assert.deepStrictEqual(actualSize, {width: 500, height: 232});
-    });
-
-    it('restores normal window state from fullscreen twice before resizing', async () => {
-      const {mcpPage, pptrPage} = await createMcpPage();
-      const browser = createMockPuppeteerBrowser();
-      pptrPage.browser.returns(browser);
-      pptrPage.windowId.resolves('win-1');
-      browser.getWindowBounds.resolves({windowState: 'fullscreen'});
-      pptrPage.cdpSession.send.withArgs('Page.getLayoutMetrics').resolves({
-        cssLayoutViewport: {
-          clientWidth: 800,
-          clientHeight: 600,
-          pageX: 0,
-          pageY: 0,
-        },
-      });
-
-      const actualSize = await mcpPage.resize(800, 600);
-
-      sinon.assert.calledTwice(browser.setWindowBounds);
-      sinon.assert.calledWithExactly(
-        browser.setWindowBounds.firstCall,
-        'win-1',
-        {windowState: 'normal'},
-      );
-      sinon.assert.calledWithExactly(
-        browser.setWindowBounds.secondCall,
-        'win-1',
-        {windowState: 'normal'},
-      );
-      sinon.assert.calledOnceWithExactly(pptrPage.resize, {
-        contentWidth: 800,
-        contentHeight: 600,
-      });
-      assert.deepStrictEqual(actualSize, {width: 800, height: 600});
-    });
-
-    it('continues resizing when window bounds APIs are unsupported', async () => {
-      const {mcpPage, pptrPage} = await createMcpPage();
-      pptrPage.windowId.rejects(new Error('Window APIs not supported'));
-      pptrPage.cdpSession.send.withArgs('Page.getLayoutMetrics').resolves({
-        cssLayoutViewport: {
-          clientWidth: 700,
-          clientHeight: 500,
-          pageX: 0,
-          pageY: 0,
-        },
-      });
-
-      const actualSize = await mcpPage.resize(700, 500);
-
-      sinon.assert.calledOnceWithExactly(pptrPage.resize, {
-        contentWidth: 700,
-        contentHeight: 500,
-      });
-      assert.deepStrictEqual(actualSize, {width: 700, height: 500});
-    });
-
-    it('returns undefined without reading layout metrics when a dialog is open', async () => {
-      const {mcpPage, pptrPage} = await createMcpPage();
-      pptrPage.windowId.rejects(new Error('Window APIs not supported'));
-      pptrPage.emit('dialog', createMockDialog());
-
-      const actualSize = await mcpPage.resize(700, 500);
-
-      sinon.assert.calledOnceWithExactly(pptrPage.resize, {
-        contentWidth: 700,
-        contentHeight: 500,
-      });
-      sinon.assert.neverCalledWith(
-        pptrPage.cdpSession.send,
-        'Page.getLayoutMetrics',
-      );
-      assert.strictEqual(actualSize, undefined);
-    });
-  });
-
   describe('dialogs', () => {
     it('returns the dialog and throws when unhandled', async () => {
       const {mcpPage, pptrPage} = await createMcpPage();

tests/tools/pages.test.ts

@@ -1537,85 +1537,6 @@ describe('pages', () => {
       });
     });
 
-    it('reports actual page dimensions when the browser clamps width or height', async () => {
-      const {page, response, context, args} = createHandlerMocks();
-      page.resize.resolves({width: 500, height: 100});
-
-      await resizePage(args).handler(
-        {
-          params: {width: 100, height: 100},
-          page,
-        },
-        response,
-        context,
-      );
-
-      sinon.assert.calledOnceWithExactly(page.resize, 100, 100);
-      sinon.assert.calledOnceWithExactly(
-        response.appendResponseLine,
-        'Requested 100x100, page is 500x100',
-      );
-      sinon.assert.calledOnceWithExactly(response.setIncludePages, true);
-
-      const heightMocks = createHandlerMocks();
-      heightMocks.page.resize.resolves({width: 800, height: 232});
-
-      await resizePage(heightMocks.args).handler(
-        {
-          params: {width: 800, height: 100},
-          page: heightMocks.page,
-        },
-        heightMocks.response,
-        heightMocks.context,
-      );
-
-      sinon.assert.calledOnceWithExactly(heightMocks.page.resize, 800, 100);
-      sinon.assert.calledOnceWithExactly(
-        heightMocks.response.appendResponseLine,
-        'Requested 800x100, page is 800x232',
-      );
-      sinon.assert.calledOnceWithExactly(
-        heightMocks.response.setIncludePages,
-        true,
-      );
-    });
-
-    it('does not append a size warning when the page matches requested dimensions', async () => {
-      const {page, response, context, args} = createHandlerMocks();
-      page.resize.resolves({width: 700, height: 500});
-
-      await resizePage(args).handler(
-        {
-          params: {width: 700, height: 500},
-          page,
-        },
-        response,
-        context,
-      );
-
-      sinon.assert.calledOnceWithExactly(page.resize, 700, 500);
-      sinon.assert.notCalled(response.appendResponseLine);
-      sinon.assert.calledOnceWithExactly(response.setIncludePages, true);
-    });
-
-    it('does not append a size line when the actual page size is unknown', async () => {
-      const {page, response, context, args} = createHandlerMocks();
-      page.resize.resolves(undefined);
-
-      await resizePage(args).handler(
-        {
-          params: {width: 700, height: 500},
-          page,
-        },
-        response,
-        context,
-      );
-
-      sinon.assert.calledOnceWithExactly(page.resize, 700, 500);
-      sinon.assert.notCalled(response.appendResponseLine);
-      sinon.assert.calledOnceWithExactly(response.setIncludePages, true);
-    });
-
     it('resize when window state is normal', async () => {
       await withMcpContext(async (response, context, args) => {
         const page = context.getSelectedMcpPage().pptrPage;