Update: handle entries specified with source in a specific case for perf

packages/core/core/src/resolveOptions.js

@@ -14,7 +14,7 @@ import {hashString} from '@parcel/hash';
 import {NodeFS} from '@parcel/fs';
 import {LMDBCache, FSCache} from '@parcel/cache';
 import {NodePackageManager} from '@parcel/package-manager';
-import {getRootDir, relativePath, resolveConfig} from '@parcel/utils';
+import {getRootDir, relativePath, resolveConfig, isGlob} from '@parcel/utils';
 import loadDotEnv from './loadDotEnv';
 import {toProjectPath} from './projectPath';
 import {getResolveFrom} from './requests/ParcelConfigRequest';
@@ -50,18 +50,22 @@ export default async function resolveOptions(
     entries = [path.resolve(inputCwd, initialOptions.entries)];
   }
 
+  let shouldMakeEntryReferFolder = false;
+  // if entries have the only one entry and the one is not glob and refers to directory, we need to make the entry refer to some file.
+  if (entries.length === 1 && !isGlob(entries[0])) {
+    let [entry] = entries;
+    try {
+      shouldMakeEntryReferFolder = (await inputFS.stat(entry)).isDirectory();
+    } catch {
+      // ignore failing stat call
+    }
+  }
+
+  // getRootDir treats the input as files, so getRootDir(["/home/user/myproject"]) returns "/home/user".
+  // Instead we need to make the the entry refer to some file inside the specified folders if entries refers to the directory.
   let entryRoot = getRootDir(
-    await Promise.all(
-      entries.map(async entry =>
-        // getRootDir treats the input as files, so getRootDir(["/home/user/myproject"]) returns "/home/user".
-        // Instead we need to make the entries refer to some file inside the specified folders.
-        (await inputFS.stat(entry)).isFile()
-          ? entry
-          : path.join(entry, 'index'),
-      ),
-    ),
+    shouldMakeEntryReferFolder ? [path.join(entries[0], 'index')] : entries,
   );
-
   let projectRootFile =
     (await resolveConfig(
       inputFS,