fix: show a warning when browser.isolate is used (#9410)

Author: sheremet-va

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

@@ -736,6 +736,11 @@ export function resolveConfig(
 
   resolved.browser.enabled ??= false
   resolved.browser.headless ??= isCI
+  if (resolved.browser.isolate) {
+    logger.console.warn(
+      c.yellow('`browser.isolate` is deprecated. Use top-level `isolate` instead.'),
+    )
+  }
   resolved.browser.isolate ??= resolved.isolate ?? true
   resolved.browser.fileParallelism
     ??= options.fileParallelism ?? mode !== 'benchmark'

test/coverage-test/test/isolation.test.ts

@@ -27,10 +27,6 @@ for (const isolate of [true, false]) {
         coverage: {
           reporter: 'json',
         },
-
-        browser: {
-          isolate,
-        },
       })
 
       const coverageMap = await readCoverageMap()