fix(reporters): write buffered stdout/stderr on process exit

Author: AriPerkkio

packages/vitest/src/node/reporters/renderers/windowedRenderer.ts

@@ -2,6 +2,7 @@ import type { Writable } from 'node:stream'
 import type { Vitest } from '../../core'
 import { stripVTControlCharacters } from 'node:util'
 import restoreCursor from 'restore-cursor'
+import { onExit } from 'signal-exit'
 
 const DEFAULT_RENDER_INTERVAL = 16
 
@@ -54,6 +55,9 @@ export class WindowRenderer {
     restoreCursor()
     this.write(HIDE_CURSOR, 'output')
 
+    // Write buffered content on unexpected exits, e.g. direct `process.exit()` calls
+    onExit(() => this.flushBuffer())
+
     this.start()
   }