You can pass the tests directly

lib/runifmain.js

@@ -10,8 +10,12 @@ import { errorreporter, summaryreporter } from '../index.js'
 const runifmain = async (meta, fn, ...args) => {
   if (!isMain(meta)) return
 
+  if (fn.name === 'runner' && fn.run) {
     if (args.length == 0) args.push(summaryreporter(), errorreporter())
+    await fn.run(...args)
+  } else {
     await fn(...args)
   }
+}
 
 export { runifmain }