minor fix

core-java/src/test/java/com/baeldung/java8/JavaFolderSizeUnitTest.java

@@ -1,21 +1,25 @@
 package com.baeldung.java8;
 
-import org.apache.commons.io.FileUtils;
+import static org.junit.Assert.assertEquals;
-import org.junit.Before;
-import org.junit.Test;
 
 import java.io.File;
 import java.io.IOException;
-import java.nio.file.*;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.SimpleFileVisitor;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.text.DecimalFormat;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.stream.StreamSupport;
 
-import static org.junit.Assert.assertEquals;
+import org.apache.commons.io.FileUtils;
+import org.junit.Before;
+import org.junit.Test;
 
 public class JavaFolderSizeUnitTest {
-
+    private final long EXPECTED_SIZE = 260;
     private String path;
 
     @Before
@@ -26,18 +30,14 @@ public class JavaFolderSizeUnitTest {
 
     @Test
     public void whenGetFolderSizeRecursive_thenCorrect() {
-        final long expectedSize = 136;
-
         final File folder = new File(path);
         final long size = getFolderSize(folder);
 
-        assertEquals(expectedSize, size);
+        assertEquals(EXPECTED_SIZE, size);
     }
 
     @Test
     public void whenGetFolderSizeUsingJava7_thenCorrect() throws IOException {
-        final long expectedSize = 136;
-
         final AtomicLong size = new AtomicLong(0);
         final Path folder = Paths.get(path);
 
@@ -49,41 +49,33 @@ public class JavaFolderSizeUnitTest {
             }
         });
 
-        assertEquals(expectedSize, size.longValue());
+        assertEquals(EXPECTED_SIZE, size.longValue());
     }
 
     @Test
     public void whenGetFolderSizeUsingJava8_thenCorrect() throws IOException {
-        final long expectedSize = 136;
-
         final Path folder = Paths.get(path);
         final long size = Files.walk(folder).filter(p -> p.toFile().isFile()).mapToLong(p -> p.toFile().length()).sum();
 
-        assertEquals(expectedSize, size);
+        assertEquals(EXPECTED_SIZE, size);
     }
 
     @Test
     public void whenGetFolderSizeUsingApacheCommonsIO_thenCorrect() {
-        final long expectedSize = 136;
-
         final File folder = new File(path);
         final long size = FileUtils.sizeOfDirectory(folder);
 
-        assertEquals(expectedSize, size);
+        assertEquals(EXPECTED_SIZE, size);
     }
 
     @Test
     public void whenGetFolderSizeUsingGuava_thenCorrect() {
-        final long expectedSize = 136;
-
         final File folder = new File(path);
 
         final Iterable<File> files = com.google.common.io.Files.fileTreeTraverser().breadthFirstTraversal(folder);
-        final long size = StreamSupport.stream(files.spliterator(), false)
+        final long size = StreamSupport.stream(files.spliterator(), false).filter(File::isFile).mapToLong(File::length).sum();
-          .filter(File::isFile)
-          .mapToLong(File::length).sum();
 
-        assertEquals(expectedSize, size);
+        assertEquals(EXPECTED_SIZE, size);
     }
 
     @Test
@@ -91,19 +83,19 @@ public class JavaFolderSizeUnitTest {
         final File folder = new File(path);
         final long size = getFolderSize(folder);
 
-        final String[] units = new String[]{"B", "KB", "MB", "GB", "TB"};
+        final String[] units = new String[] { "B", "KB", "MB", "GB", "TB" };
         final int unitIndex = (int) (Math.log10(size) / 3);
         final double unitValue = 1 << (unitIndex * 10);
 
         final String readableSize = new DecimalFormat("#,##0.#").format(size / unitValue) + " " + units[unitIndex];
-        assertEquals("136 B", readableSize);
+        assertEquals(EXPECTED_SIZE + " B", readableSize);
     }
 
     private long getFolderSize(final File folder) {
         long length = 0;
         final File[] files = folder.listFiles();
 
-        for (File file : files) {
+        for (final File file : files) {
             if (file.isFile()) {
                 length += file.length();
             } else {