Merge pull request #521 from jprichardson/async-filter

Apply the async filter to initial filter checking in copy

lib/copy/copy.js

@@ -35,8 +35,11 @@ function copy (src, dest, opts, cb) {
   // don't allow src and dest to be the same
   if (src === dest) return cb(new Error('Source and destination must not be the same.'))
 
-  if (opts.filter && !opts.filter(src, dest)) return cb()
+  if (opts.filter) return handleFilter(checkParentDir, src, dest, opts, cb)
+  return checkParentDir(src, dest, opts, cb)
+}
 
+function checkParentDir (src, dest, opts, cb) {
   const destParent = path.dirname(dest)
   pathExists(destParent, (err, dirExists) => {
     if (err) return cb(err)
@@ -49,13 +52,16 @@ function copy (src, dest, opts, cb) {
 }
 
 function startCopy (src, dest, opts, cb) {
-  if (opts.filter) {
-    Promise.resolve(opts.filter(src, dest))
-      .then(include => {
-        if (include) getStats(src, dest, opts, cb)
-        else cb()
-      }, error => cb(error))
-  } else getStats(src, dest, opts, cb)
+  if (opts.filter) return handleFilter(getStats, src, dest, opts, cb)
+  return getStats(src, dest, opts, cb)
+}
+
+function handleFilter (onInclude, src, dest, opts, cb) {
+  Promise.resolve(opts.filter(src, dest))
+    .then(include => {
+      if (include) return onInclude(src, dest, opts, cb)
+      return cb()
+    }, error => cb(error))
 }
 
 function getStats (src, dest, opts, cb) {