perf: avoid extra call stat for file (#365)

Author: evilebottnawi

src/postProcessPattern.js

@@ -25,7 +25,11 @@ export default function postProcessPattern(globalRef, pattern, file) {
 
   logger.debug(`getting stats for '${file.absoluteFrom}' to write to assets`);
 
-  return stat(inputFileSystem, file.absoluteFrom).then((stats) => {
+  const getStats = pattern.stats
+    ? Promise.resolve().then(() => pattern.stats)
+    : stat(inputFileSystem, file.absoluteFrom);
+
+  return getStats.then((stats) => {
     // We don't write empty directories
     if (stats.isDirectory()) {
       logger.debug(

src/preProcessPattern.js

@@ -158,6 +158,7 @@ export default function preProcessPattern(globalRef, pattern) {
 
         fileDependencies.add(pattern.absoluteFrom);
 
+        pattern.stats = stats;
         pattern.fromType = 'file';
         pattern.context = path.dirname(pattern.absoluteFrom);
         pattern.glob = normalize(pattern.absoluteFrom);