Ensure copy filter fn is not called more than needed (#883)

Fixes #809

Author: RyanZim

lib/copy-sync/__tests__/copy-sync-file.test.js

@@ -104,6 +104,25 @@ describe('+ copySync() / file', () => {
       assert(fs.existsSync(destFile3))
     })
 
+    it('should not call filter fn more than needed', () => {
+      const src = path.join(TEST_DIR, 'foo')
+
+      fs.writeFileSync(src, '')
+
+      const dest = path.join(TEST_DIR, 'bar')
+
+      let filterCallCount = 0
+      const filter = () => {
+        filterCallCount++
+        return true
+      }
+
+      fs.copySync(src, dest, filter)
+
+      assert.strictEqual(filterCallCount, 1)
+      assert(fs.existsSync(dest))
+    })
+
     describe('> when the destination dir does not exist', () => {
       it('should create the destination directory and copy the file', () => {
         const src = path.join(TEST_DIR, 'file.txt')

lib/copy-sync/copy-sync.js

@@ -30,7 +30,7 @@ function handleFilterAndCopy (destStat, src, dest, opts) {
   if (opts.filter && !opts.filter(src, dest)) return
   const destParent = path.dirname(dest)
   if (!fs.existsSync(destParent)) mkdirsSync(destParent)
-  return startCopy(destStat, src, dest, opts)
+  return getStats(destStat, src, dest, opts)
 }
 
 function startCopy (destStat, src, dest, opts) {

lib/copy/__tests__/copy.test.js

@@ -283,6 +283,25 @@ describe('fs-extra', () => {
         })
       })
 
+      it('should not call filter fn more than needed', done => {
+        const src = path.join(TEST_DIR, 'foo')
+        fs.writeFileSync(src, '')
+        const dest = path.join(TEST_DIR, 'bar')
+
+        let filterCallCount = 0
+        const filter = () => {
+          filterCallCount++
+          return true
+        }
+
+        fse.copy(src, dest, filter, err => {
+          assert(!err)
+          assert.strictEqual(filterCallCount, 1)
+          assert(fs.existsSync(dest))
+          done()
+        })
+      })
+
       it('accepts options object in place of filter', done => {
         const srcFile1 = path.join(TEST_DIR, '1.jade')
         fs.writeFileSync(srcFile1, '')

lib/copy/copy.js

@@ -42,10 +42,10 @@ function checkParentDir (destStat, src, dest, opts, cb) {
   const destParent = path.dirname(dest)
   pathExists(destParent, (err, dirExists) => {
     if (err) return cb(err)
-    if (dirExists) return startCopy(destStat, src, dest, opts, cb)
+    if (dirExists) return getStats(destStat, src, dest, opts, cb)
     mkdirs(destParent, err => {
       if (err) return cb(err)
-      return startCopy(destStat, src, dest, opts, cb)
+      return getStats(destStat, src, dest, opts, cb)
     })
   })
 }