AccumulatorPathVisitor does not track directories properly.

Author: Gary Gregory

src/changes/changes.xml

@@ -63,6 +63,9 @@ The <action> type attribute can be add,update,fix,remove.
       <action dev="ggregory" type="fix" due-to="Michiel Kalkman">
         FileUtils#copyDirectory(File, File, FileFilter, preserveFileDate) clean up #163.
       </action>
+      <action dev="ggregory" type="fix" due-to="Michiel Kalkman">
+        AccumulatorPathVisitor does not track directories properly.
+      </action>
       <!-- ADD -->
       <action dev="ggregory" type="add" due-to="Gary Gregory">
         Add FileSystemProviders class.

src/main/java/org/apache/commons/io/file/AccumulatorPathVisitor.java

@@ -19,7 +19,6 @@
 
 import java.io.IOException;
 import java.nio.file.FileVisitResult;
-import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.ArrayList;
@@ -70,6 +69,10 @@ public AccumulatorPathVisitor(final PathCounters pathCounter) {
         super(pathCounter);
     }
 
+    private void add(final List<Path> list, final Path dir) {
+        list.add(dir.normalize());
+    }
+
     @Override
     public boolean equals(final Object obj) {
         if (this == obj) {
@@ -111,6 +114,12 @@ public int hashCode() {
         return result;
     }
 
+    @Override
+    public FileVisitResult postVisitDirectory(final Path dir, final IOException exc) throws IOException {
+        add(dirList, dir);
+        return super.postVisitDirectory(dir, exc);
+    }
+
     /**
      * Relativizes each directory path with {@link Path#relativize(Path)} against the given {@code parent}, optionally
      * sorting the result.
@@ -120,7 +129,8 @@ public int hashCode() {
      * @param comparator How to sort, null uses default sorting.
      * @return A new list
      */
-    public List<Path> relativizeDirectories(final Path parent, final boolean sort, final Comparator<? super Path> comparator) {
+    public List<Path> relativizeDirectories(final Path parent, final boolean sort,
+        final Comparator<? super Path> comparator) {
         return PathUtils.relativize(getDirList(), parent, sort, comparator);
     }
 
@@ -133,13 +143,14 @@ public List<Path> relativizeDirectories(final Path parent, final boolean sort, f
      * @param comparator How to sort, null uses default sorting.
      * @return A new list
      */
-    public List<Path> relativizeFiles(final Path parent, final boolean sort, final Comparator<? super Path> comparator) {
+    public List<Path> relativizeFiles(final Path parent, final boolean sort,
+        final Comparator<? super Path> comparator) {
         return PathUtils.relativize(getFileList(), parent, sort, comparator);
     }
 
     @Override
     public FileVisitResult visitFile(final Path file, final BasicFileAttributes attributes) throws IOException {
-        ((Files.isDirectory(file)) ? dirList : fileList).add(file.normalize());
+        add(fileList, file);
         return super.visitFile(file, attributes);
     }
 

src/test/java/org/apache/commons/io/file/AccumulatorPathVisitorTest.java

@@ -0,0 +1,99 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.io.file;
+
+import static org.apache.commons.io.file.CounterAssertions.assertCounts;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import org.apache.commons.io.filefilter.AndFileFilter;
+import org.apache.commons.io.filefilter.DirectoryFileFilter;
+import org.apache.commons.io.filefilter.EmptyFileFilter;
+import org.apache.commons.io.filefilter.PathVisitorFileFilter;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+public class AccumulatorPathVisitorTest {
+
+    @TempDir
+    File tempDirFile;
+
+    /**
+     * Tests an empty folder.
+     */
+    @Test
+    public void testEmptyFolder() throws IOException {
+        final Path tempDir = tempDirFile.toPath();
+        final AccumulatorPathVisitor accPathVisitor = AccumulatorPathVisitor.withLongCounters();
+        final PathVisitorFileFilter countingFileFilter = new PathVisitorFileFilter(accPathVisitor);
+        Files.walkFileTree(tempDir,
+            new AndFileFilter(countingFileFilter, DirectoryFileFilter.INSTANCE, EmptyFileFilter.EMPTY));
+        assertCounts(1, 0, 0, accPathVisitor.getPathCounters());
+        assertEquals(1, accPathVisitor.getDirList().size());
+        assertTrue(accPathVisitor.getFileList().isEmpty());
+    }
+
+    /**
+     * Tests a directory with one file of size 0.
+     */
+    @Test
+    public void testFolders1FileSize0() throws IOException {
+        final AccumulatorPathVisitor accPathVisitor = AccumulatorPathVisitor.withLongCounters();
+        final PathVisitorFileFilter countingFileFilter = new PathVisitorFileFilter(accPathVisitor);
+        Files.walkFileTree(Paths.get("src/test/resources/org/apache/commons/io/dirs-1-file-size-0"),
+            countingFileFilter);
+        assertCounts(1, 1, 0, accPathVisitor.getPathCounters());
+        assertEquals(1, accPathVisitor.getDirList().size());
+        assertEquals(1, accPathVisitor.getFileList().size());
+    }
+
+    /**
+     * Tests a directory with one file of size 1.
+     */
+    @Test
+    public void testFolders1FileSize1() throws IOException {
+        final AccumulatorPathVisitor accPathVisitor = AccumulatorPathVisitor.withLongCounters();
+        final PathVisitorFileFilter countingFileFilter = new PathVisitorFileFilter(accPathVisitor);
+        Files.walkFileTree(Paths.get("src/test/resources/org/apache/commons/io/dirs-1-file-size-1"),
+            countingFileFilter);
+        assertCounts(1, 1, 1, accPathVisitor.getPathCounters());
+        assertEquals(1, accPathVisitor.getDirList().size());
+        assertEquals(1, accPathVisitor.getFileList().size());
+    }
+
+    /**
+     * Tests a directory with two subdirectories, each containing one file of size 1.
+     */
+    @Test
+    public void testFolders2FileSize2() throws IOException {
+        final AccumulatorPathVisitor accPathVisitor = AccumulatorPathVisitor.withLongCounters();
+        final PathVisitorFileFilter countingFileFilter = new PathVisitorFileFilter(accPathVisitor);
+        Files.walkFileTree(Paths.get("src/test/resources/org/apache/commons/io/dirs-2-file-size-2"),
+            countingFileFilter);
+        assertCounts(3, 2, 2, accPathVisitor.getPathCounters());
+        assertEquals(3, accPathVisitor.getDirList().size());
+        assertEquals(2, accPathVisitor.getFileList().size());
+
+    }
+}