fix(vm-threads): don't crash on percentage based memoryLimit (#4802)

Co-authored-by: Ari Perkkiö <ari.perkkio@gmail.com>

Author: inottn

packages/vitest/src/node/pools/vm-threads.ts

@@ -170,9 +170,10 @@ function getMemoryLimit(config: ResolvedConfig) {
     )
   }
 
-  if (limit && limit > 1)
+  // If totalmem is not supported we cannot resolve percentage based values like 0.5, "50%"
+  if ((typeof limit === 'number' && limit > 1) || (typeof limit === 'string' && limit.at(-1) !== '%'))
     return stringToBytes(limit)
 
-  // just ignore "experimentalVmWorkerMemoryLimit" value because we cannot detect memory limit
+  // just ignore "memoryLimit" value because we cannot detect memory limit
   return null
 }

packages/vitest/src/utils/memory-limit.ts

@@ -23,7 +23,7 @@ export function getWorkerMemoryLimit(config: ResolvedConfig) {
   const memoryLimit = config.poolOptions?.vmThreads?.memoryLimit
 
   if (memoryLimit)
-    return stringToBytes(memoryLimit)
+    return memoryLimit
 
   return 1 / (config.poolOptions?.vmThreads?.maxThreads ?? getDefaultThreadsCount(config))
 }
@@ -94,7 +94,7 @@ export function stringToBytes(
       return Math.floor(input)
     }
     else {
-      throw new Error('Unexpected numerical input for "experimentalVmWorkerMemoryLimit"')
+      throw new Error('Unexpected numerical input for "memoryLimit"')
     }
   }