feat(browser): playwright provider doesn't allow resizing the browser viewport

packages/browser/src/node/providers/playwright.ts

@@ -1,6 +1,5 @@
 import type {
   Browser,
-
   BrowserContext,
   BrowserContextOptions,
   Frame,
@@ -67,10 +66,21 @@ export class PlaywrightBrowserProvider implements BrowserProvider {
 
       const playwright = await import('playwright')
 
-      const browser = await playwright[this.browserName].launch({
+      const launchOptions = {
         ...this.options?.launch,
         headless: options.headless,
-      })
+      } satisfies LaunchOptions
+
+      if (this.ctx.config.browser.launchViewport.maximized) {
+        if (!launchOptions.args) {
+          launchOptions.args = []
+        }
+        if (!launchOptions.args.includes('--start-maximized') && !launchOptions.args.includes('--start-fullscreen')) {
+          launchOptions.args.push('--start-maximized')
+        }
+      }
+
+      const browser = await playwright[this.browserName].launch(launchOptions)
       this.browser = browser
       this.browserPromise = null
       return this.browser
@@ -85,11 +95,15 @@ export class PlaywrightBrowserProvider implements BrowserProvider {
     }
 
     const browser = await this.openBrowser()
-    const context = await browser.newContext({
+    const options = {
       ...this.options?.context,
       ignoreHTTPSErrors: true,
       serviceWorkers: 'allow',
-    })
+    } satisfies BrowserContextOptions
+    if (this.ctx.config.browser.launchViewport.maximized) {
+      options.viewport = null
+    }
+    const context = await browser.newContext(options)
     this.contexts.set(contextId, context)
     return context
   }

packages/browser/src/node/providers/webdriver.ts

@@ -80,6 +80,10 @@ export class WebdriverBrowserProvider implements BrowserProvider {
       capabilities: this.buildCapabilities(),
     })
 
+    if (this.ctx.config.browser.launchViewport.maximized) {
+      await this.browser.maximizeWindow()
+    }
+
     return this.browser
   }
 

packages/vitest/src/node/config.ts

@@ -682,6 +682,8 @@ export function resolveConfig(
   resolved.browser.isolate ??= true
   resolved.browser.fileParallelism
     ??= options.fileParallelism ?? mode !== 'benchmark'
+  // don't maximize it yet, only when the ui is enabled
+  resolved.browser.launchViewport = { maximized: false }
   // disable in headless mode by default, and if CI is detected
   resolved.browser.ui ??= resolved.browser.headless === true ? false : !isCI
   if (resolved.browser.screenshotDirectory) {
@@ -723,6 +725,7 @@ export function resolveConfig(
   // enable includeTaskLocation by default in UI mode
   if (resolved.browser.enabled) {
     if (resolved.browser.ui) {
+      resolved.browser.launchViewport.maximized = true
       resolved.includeTaskLocation ??= true
     }
   }

packages/vitest/src/types/browser.ts

@@ -236,4 +236,7 @@ export interface ResolvedBrowserOptions extends BrowserConfigOptions {
     width: number
     height: number
   }
+  launchViewport: {
+    maximized: boolean
+  }
 }