fix: apply browser CLI options only if the project has the browser set in the config already

packages/vitest/src/node/cli/cac.ts

@@ -283,10 +283,6 @@ function normalizeCliOptions(cliFilters: string[], argv: CliOptions): CliOptions
     argv.includeTaskLocation ??= true
   }
 
-  // running "vitest --browser.headless"
-  if (typeof argv.browser === 'object' && !('enabled' in argv.browser)) {
-    argv.browser.enabled = true
-  }
   if (typeof argv.typecheck?.only === 'boolean') {
     argv.typecheck.enabled ??= true
   }

packages/vitest/src/node/cli/cli-config.ts

@@ -361,7 +361,7 @@ export const cliOptionsConfig: VitestCLIOptions = {
         return { enabled: browser === 'yes' }
       }
       if (typeof browser === 'string') {
-        return { enabled: true, name: browser }
+        return { name: browser }
       }
       return browser
     },

packages/vitest/src/node/config/resolveConfig.ts

@@ -1,6 +1,7 @@
 import type { ResolvedConfig as ResolvedViteConfig } from 'vite'
 import type { Vitest } from '../core'
 import type { BenchmarkBuiltinReporters } from '../reporters'
+import type { ResolvedBrowserOptions } from '../types/browser'
 import type {
   ApiConfig,
   ResolvedConfig,
@@ -13,6 +14,7 @@ import { toArray } from '@vitest/utils'
 import { resolveModule } from 'local-pkg'
 import { normalize, relative, resolve } from 'pathe'
 import c from 'tinyrainbow'
+import { mergeConfig } from 'vite'
 import {
   defaultBrowserPort,
   defaultInspectPort,
@@ -205,8 +207,6 @@ export function resolveConfig(
     resolved.minWorkers = resolveInlineWorkerOption(resolved.minWorkers)
   }
 
-  resolved.browser ??= {} as any
-
   // run benchmark sequentially by default
   resolved.fileParallelism ??= mode !== 'benchmark'
 
@@ -238,10 +238,23 @@ export function resolveConfig(
     }
   }
 
+  // apply browser CLI options only if the config already has the browser config and not disabled manually
+  if (
+    vitest._cliOptions.browser
+    && resolved.browser
+    // if enabled is set to `false`, but CLI overrides it, then always override it
+    && (resolved.browser.enabled !== false || vitest._cliOptions.browser.enabled)
+  ) {
+    resolved.browser = mergeConfig(
+      resolved.browser,
+      vitest._cliOptions.browser,
+    ) as ResolvedBrowserOptions
+  }
+
+  resolved.browser ??= {} as any
   const browser = resolved.browser
 
-  // if browser was enabled via CLI and it's configured by the user, then validate the input
-  if (browser.enabled && viteConfig.test?.browser) {
+  if (browser.enabled) {
     if (!browser.name && !browser.instances) {
       throw new Error(`Vitest Browser Mode requires "browser.name" (deprecated) or "browser.instances" options, none were set.`)
     }
@@ -806,7 +819,6 @@ export function resolveConfig(
     )
   }
 
-  resolved.browser ??= {} as any
   resolved.browser.enabled ??= false
   resolved.browser.headless ??= isCI
   resolved.browser.isolate ??= true

packages/vitest/src/node/core.ts

@@ -5,6 +5,7 @@ import type { ViteDevServer } from 'vite'
 import type { defineWorkspace } from 'vitest/config'
 import type { SerializedCoverageConfig } from '../runtime/config'
 import type { ArgumentsType, ProvidedContext, UserConsoleLog } from '../types/general'
+import type { CliOptions } from './cli/cli-api'
 import type { ProcessPool, WorkspaceSpec } from './pool'
 import type { TestSpecification } from './spec'
 import type { ResolvedConfig, TestProjectConfiguration, UserConfig, VitestRunMode } from './types/config'
@@ -97,7 +98,7 @@ export class Vitest {
   resolvedProjects: TestProject[] = []
   /** @internal */ _browserLastPort = defaultBrowserPort
   /** @internal */ _browserSessions = new BrowserSessions()
-  /** @internal */ _options: UserConfig = {}
+  /** @internal */ _cliOptions: CliOptions = {}
   /** @internal */ reporters: Reporter[] = []
   /** @internal */ vitenode: ViteNodeServer = undefined!
   /** @internal */ runner: ViteNodeRunner = undefined!
@@ -118,8 +119,10 @@ export class Vitest {
 
   constructor(
     public readonly mode: VitestRunMode,
+    cliOptions: UserConfig,
     options: VitestOptions = {},
   ) {
+    this._cliOptions = cliOptions
     this.logger = new Logger(this, options.stdout, options.stderr)
     this.packageInstaller = options.packageInstaller || new VitestPackageInstaller()
     this.specifications = new VitestSpecifications(this)
@@ -192,13 +195,12 @@ export class Vitest {
   }
 
   /** @deprecated internal */
-  setServer(options: UserConfig, server: ViteDevServer, cliOptions: UserConfig): Promise<void> {
-    return this._setServer(options, server, cliOptions)
+  setServer(options: UserConfig, server: ViteDevServer): Promise<void> {
+    return this._setServer(options, server)
   }
 
   /** @internal */
-  async _setServer(options: UserConfig, server: ViteDevServer, cliOptions: UserConfig) {
-    this._options = options
+  async _setServer(options: UserConfig, server: ViteDevServer) {
     this.watcher.unregisterWatcher()
     clearTimeout(this._rerunTimer)
     this.restartsCount += 1
@@ -274,7 +276,7 @@ export class Vitest {
     }
     catch { }
 
-    const projects = await this.resolveProjects(cliOptions)
+    const projects = await this.resolveProjects(this._cliOptions)
     this.resolvedProjects = projects
     this.projects = projects
 
@@ -287,7 +289,7 @@ export class Vitest {
       }))
     }))
 
-    if (options.browser?.enabled) {
+    if (this._cliOptions.browser?.enabled) {
       const browserProjects = this.projects.filter(p => p.config.browser.enabled)
       if (!browserProjects.length) {
         throw new Error(`Vitest received --browser flag, but no project had a browser configuration.`)
@@ -327,7 +329,7 @@ export class Vitest {
     const currentNames = new Set(this.projects.map(p => p.name))
     const projects = await resolveProjects(
       this,
-      this._options,
+      this._cliOptions,
       undefined,
       Array.isArray(config) ? config : [config],
       currentNames,
@@ -1335,7 +1337,7 @@ export class Vitest {
    * Check if the project with a given name should be included.
    */
   matchesProjectFilter(name: string): boolean {
-    const projects = this._config?.project || this._options?.project
+    const projects = this._config?.project || this._cliOptions?.project
     // no filters applied, any project can be included
     if (!projects || !projects.length) {
       return true

packages/vitest/src/node/create.ts

@@ -6,7 +6,7 @@ import type { CliOptions } from './cli/cli-api'
 import type { VitestOptions } from './core'
 import type { VitestRunMode } from './types/config'
 import { resolve } from 'node:path'
-import { slash } from '@vitest/utils'
+import { deepClone, slash } from '@vitest/utils'
 import { findUp } from 'find-up'
 import { mergeConfig } from 'vite'
 import { configFiles } from '../constants'
@@ -20,7 +20,7 @@ export async function createVitest(
   viteOverrides: ViteUserConfig = {},
   vitestOptions: VitestOptions = {},
 ): Promise<Vitest> {
-  const ctx = new Vitest(mode, vitestOptions)
+  const ctx = new Vitest(mode, deepClone(options), vitestOptions)
   const root = slash(resolve(options.root || process.cwd()))
 
   const configPath
@@ -32,12 +32,14 @@ export async function createVitest(
 
   options.config = configPath
 
+  const { browser: _removeBrowser, ...restOptions } = options
+
   const config: ViteInlineConfig = {
     configFile: configPath,
     configLoader: options.configLoader,
     // this will make "mode": "test" | "benchmark" inside defineConfig
     mode: options.mode || mode,
-    plugins: await VitestPlugin(options, ctx),
+    plugins: await VitestPlugin(restOptions, ctx),
   }
 
   const server = await createViteServer(

packages/vitest/src/node/plugins/index.ts

@@ -1,6 +1,7 @@
 import type { UserConfig as ViteConfig, Plugin as VitePlugin } from 'vite'
 import type { ResolvedConfig, UserConfig } from '../types/config'
 import {
+  deepClone,
   deepMerge,
   notNullish,
   toArray,
@@ -27,13 +28,13 @@ import { VitestCoreResolver } from './vitestResolver'
 
 export async function VitestPlugin(
   options: UserConfig = {},
-  ctx: Vitest = new Vitest('test'),
+  vitest: Vitest = new Vitest('test', deepClone(options)),
 ): Promise<VitePlugin[]> {
   const userConfig = deepMerge({}, options) as UserConfig
 
   async function UIPlugin() {
-    await ctx.packageInstaller.ensureInstalled('@vitest/ui', options.root || process.cwd(), ctx.version)
-    return (await import('@vitest/ui')).default(ctx)
+    await vitest.packageInstaller.ensureInstalled('@vitest/ui', options.root || process.cwd(), vitest.version)
+    return (await import('@vitest/ui')).default(vitest)
   }
 
   return [
@@ -143,13 +144,13 @@ export async function VitestPlugin(
           },
         }
 
-        if (ctx.configOverride.project) {
+        if (vitest.configOverride.project) {
           // project filter was set by the user, so we need to filter the project
-          options.project = ctx.configOverride.project
+          options.project = vitest.configOverride.project
         }
 
         config.customLogger = createViteLogger(
-          ctx.logger,
+          vitest.logger,
           viteConfig.logLevel || 'warn',
           {
             allowClearScreen: false,
@@ -207,7 +208,7 @@ export async function VitestPlugin(
               name: string,
               filename: string,
             ) => {
-              const root = ctx.config.root || options.root || process.cwd()
+              const root = vitest.config.root || options.root || process.cwd()
               return generateScopedClassName(
                 classNameStrategy,
                 name,
@@ -258,7 +259,7 @@ export async function VitestPlugin(
         })
 
         const originalName = options.name
-        if (options.browser?.enabled && options.browser?.instances) {
+        if (options.browser?.instances) {
           options.browser.instances.forEach((instance) => {
             instance.name ??= originalName ? `${originalName} (${instance.browser})` : instance.browser
           })
@@ -274,9 +275,9 @@ export async function VitestPlugin(
               console.log('[debug] watcher is ready')
             })
           }
-          await ctx._setServer(options, server, userConfig)
+          await vitest._setServer(options, server)
           if (options.api && options.watch) {
-            (await import('../../api/setup')).setup(ctx)
+            (await import('../../api/setup')).setup(vitest)
           }
 
           // #415, in run mode we don't need the watcher, close it would improve the performance
@@ -287,9 +288,9 @@ export async function VitestPlugin(
       },
     },
     SsrReplacerPlugin(),
-    ...CSSEnablerPlugin(ctx),
-    CoverageTransform(ctx),
-    VitestCoreResolver(ctx),
+    ...CSSEnablerPlugin(vitest),
+    CoverageTransform(vitest),
+    VitestCoreResolver(vitest),
     options.ui ? await UIPlugin() : null,
     ...MocksPlugins(),
     VitestOptimizer(),

packages/vitest/src/node/plugins/publicConfig.ts

@@ -3,7 +3,7 @@ import type {
   UserConfig as ViteUserConfig,
 } from 'vite'
 import type { ResolvedConfig, UserConfig } from '../types/config'
-import { slash } from '@vitest/utils'
+import { deepClone, slash } from '@vitest/utils'
 import { findUp } from 'find-up'
 import { resolve } from 'pathe'
 import { mergeConfig, resolveConfig as resolveViteConfig } from 'vite'
@@ -27,7 +27,7 @@ export async function resolveConfig(
         : await findUp(configFiles, { cwd: root } as any)
   options.config = configPath
 
-  const vitest = new Vitest('test')
+  const vitest = new Vitest('test', deepClone(options))
   const config = await resolveViteConfig(
     mergeConfig(
       {

packages/vitest/src/node/plugins/workspace.ts

@@ -4,7 +4,6 @@ import type { ResolvedConfig, TestProjectInlineConfiguration } from '../types/co
 import { existsSync, readFileSync } from 'node:fs'
 import { deepMerge } from '@vitest/utils'
 import { basename, dirname, relative, resolve } from 'pathe'
-import { mergeConfig } from 'vite'
 import { configDefaults } from '../../defaults'
 import { generateScopedClassName } from '../../integrations/css/css-modules'
 import { VitestFilteredOutProjectError } from '../errors'
@@ -116,32 +115,25 @@ export function WorkspaceVitestPlugin(
           },
         }
 
-        // if this project defines a browser configuration, respect --browser flag
-        // otherwise if we always override the configuration, every project will run in browser mode
-        if (project.vitest._options.browser && viteConfig.test?.browser) {
-          viteConfig.test.browser = mergeConfig(
-            viteConfig.test.browser,
-            project.vitest._options.browser,
-          )
-        }
-
-        (config.test as ResolvedConfig).defines = defines
+        ;(config.test as ResolvedConfig).defines = defines
 
+        const isUserBrowserEnabled = viteConfig.test?.browser?.enabled
+        const isBrowserEnabled = isUserBrowserEnabled ?? (viteConfig.test?.browser && project.vitest._cliOptions.browser?.enabled)
         // keep project names to potentially filter it out
         const workspaceNames = [name]
-        if (viteConfig.test?.browser?.enabled) {
-          if (viteConfig.test.browser.name && !viteConfig.test.browser.instances?.length) {
-            const browser = viteConfig.test.browser.name
-            // vitest injects `instances` in this case later on
-            workspaceNames.push(name ? `${name} (${browser})` : browser)
-          }
+        const browser = viteConfig.test!.browser || {}
+        if (isBrowserEnabled && browser.name && !browser.instances?.length) {
+          // vitest injects `instances` in this case later on
+          workspaceNames.push(name ? `${name} (${browser.name})` : browser.name)
+        }
 
-          viteConfig.test.browser.instances?.forEach((instance) => {
-            // every instance is a potential project
-            instance.name ??= name ? `${name} (${instance.browser})` : instance.browser
+        viteConfig.test?.browser?.instances?.forEach((instance) => {
+          // every instance is a potential project
+          instance.name ??= name ? `${name} (${instance.browser})` : instance.browser
+          if (isBrowserEnabled) {
             workspaceNames.push(instance.name)
-          })
-        }
+          }
+        })
 
         const filters = project.vitest.config.project
         // if there is `--project=...` filter, check if any of the potential projects match

test/cli/fixtures/public-api/vitest.config.ts

@@ -1 +1,11 @@
-export default {}
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  test: {
+    browser: {
+      provider: 'playwright',
+      instances: [{ browser: 'chromium' }],
+      headless: true,
+    },
+  },
+})

test/cli/test/public-api.test.ts

@@ -11,9 +11,6 @@ it.each([
     name: 'running in the browser',
     browser: {
       enabled: true,
-      provider: 'playwright',
-      instances: [{ browser: 'chromium' }],
-      headless: true,
     },
   },
 ] as UserConfig[])('passes down metadata when $name', { timeout: 60_000, retry: 1 }, async (config) => {

test/config/fixtures/bail/vitest.config.ts

@@ -29,10 +29,6 @@ export default defineConfig({
     },
     browser: {
       headless: true,
-      provider: 'webdriverio',
-      instances: [
-        { browser: 'chrome' },
-      ],
     },
   },
 })

test/config/fixtures/browser-no-config/vitest.config.ts

@@ -3,7 +3,7 @@ import { defineConfig } from 'vitest/config';
 export default defineConfig({
   test: {
     browser: {
-      enabled: false,
+      headless: true,
     },
   },
 })