Fix Checkstyle violations and address review comments

Author: MiriamCohenDev

src/main/java/org/apache/commons/io/FilenameUtils.java

@@ -937,13 +937,12 @@ public static int getPrefixLength(final String fileName) {
         if (posUnix == 2 || posWin == 2) {
             return NOT_FOUND;
         }
-        int pos;
-        String hostnamePart;
-        if(posUnix == NOT_FOUND && posWin == NOT_FOUND){
+        final int pos;
+        final String hostnamePart;
+        if (posUnix == NOT_FOUND && posWin == NOT_FOUND) {
             pos = fileName.length();
             hostnamePart = fileName.substring(2);
-        }
-        else{
+        } else {
             posUnix = posUnix == NOT_FOUND ? posWin : posUnix;
             posWin = posWin == NOT_FOUND ? posUnix : posWin;
             pos = Math.min(posUnix, posWin) + 1;

src/test/java/org/apache/commons/io/FilenameUtilsTest.java

@@ -192,6 +192,7 @@ void testEqualsNormalized() {
     void testEqualsNormalizedError_IO_128() {
         assertFalse(FilenameUtils.equalsNormalizedOnSystem("//file.txt", "file.txt"));
         assertFalse(FilenameUtils.equalsNormalizedOnSystem("file.txt", "//file.txt"));
+        assertTrue(FilenameUtils.equalsNormalizedOnSystem("//file.txt", "//file.txt"));
     }
 
     @Test
@@ -316,6 +317,7 @@ void testGetFullPathNoEndSeparator() {
         assertNull(FilenameUtils.getFullPathNoEndSeparator("1:"));
         assertNull(FilenameUtils.getFullPathNoEndSeparator("1:a"));
         assertNull(FilenameUtils.getFullPathNoEndSeparator("///a/b/c.txt"));
+        assertEquals("//a", FilenameUtils.getFullPathNoEndSeparator("//a"));
 
         assertEquals("", FilenameUtils.getFullPathNoEndSeparator(""));
 
@@ -407,7 +409,7 @@ void testGetPath() {
         assertNull(FilenameUtils.getPath("1:"));
         assertNull(FilenameUtils.getPath("1:a"));
         assertNull(FilenameUtils.getPath("///a/b/c.txt"));
-        assertEquals("",FilenameUtils.getPath("//a"));
+        assertEquals("", FilenameUtils.getPath("//a"));
 
         assertEquals("", FilenameUtils.getPath(""));
         assertEquals("", FilenameUtils.getPath(DRIVE_C));
@@ -449,12 +451,13 @@ void testGetPathNoEndSeparator() {
         assertNull(FilenameUtils.getPathNoEndSeparator("1:"));
         assertNull(FilenameUtils.getPathNoEndSeparator("1:a"));
         assertNull(FilenameUtils.getPathNoEndSeparator("///a/b/c.txt"));
+        assertEquals("", FilenameUtils.getPathNoEndSeparator("//a"));
 
         assertEquals("", FilenameUtils.getPathNoEndSeparator(""));
         assertEquals("", FilenameUtils.getPathNoEndSeparator(DRIVE_C));
         assertEquals("", FilenameUtils.getPathNoEndSeparator("C:/"));
         assertEquals("", FilenameUtils.getPathNoEndSeparator("//server/"));
-        assertEquals("",FilenameUtils.getPathNoEndSeparator("//server"));
+        assertEquals("", FilenameUtils.getPathNoEndSeparator("//server"));
         assertEquals("", FilenameUtils.getPathNoEndSeparator("~"));
         assertEquals("", FilenameUtils.getPathNoEndSeparator("~/"));
         assertEquals("", FilenameUtils.getPathNoEndSeparator("~user"));
@@ -483,6 +486,7 @@ void testGetPrefix() {
         assertNull(FilenameUtils.getPrefix("1:"));
         assertNull(FilenameUtils.getPrefix("1:a"));
         assertNull(FilenameUtils.getPrefix("\\\\\\a\\b\\c.txt"));
+        assertEquals("\\\\a", FilenameUtils.getPrefix("\\\\a"));
 
         assertEquals("", FilenameUtils.getPrefix(""));
         assertEquals("\\", FilenameUtils.getPrefix("\\"));
@@ -506,7 +510,6 @@ void testGetPrefix() {
         assertEquals("\\", FilenameUtils.getPrefix("\\a\\b\\c.txt"));
         assertEquals("C:\\", FilenameUtils.getPrefix("C:\\a\\b\\c.txt"));
         assertEquals("\\\\server\\", FilenameUtils.getPrefix("\\\\server\\a\\b\\c.txt"));
-        assertEquals("\\\\a", FilenameUtils.getPrefix("\\\\a"));
 
         assertEquals("", FilenameUtils.getPrefix("a/b/c.txt"));
         assertEquals("/", FilenameUtils.getPrefix("/a/b/c.txt"));
@@ -534,6 +537,7 @@ void testGetPrefixLength() {
         assertEquals(-1, FilenameUtils.getPrefixLength("1:"));
         assertEquals(-1, FilenameUtils.getPrefixLength("1:a"));
         assertEquals(-1, FilenameUtils.getPrefixLength("\\\\\\a\\b\\c.txt"));
+        assertEquals(3, FilenameUtils.getPrefixLength("\\\\a"));
 
         assertEquals(0, FilenameUtils.getPrefixLength(""));
         assertEquals(1, FilenameUtils.getPrefixLength("\\"));
@@ -558,7 +562,6 @@ void testGetPrefixLength() {
         assertEquals(2, FilenameUtils.getPrefixLength("C:a\\b\\c.txt"));
         assertEquals(3, FilenameUtils.getPrefixLength("C:\\a\\b\\c.txt"));
         assertEquals(9, FilenameUtils.getPrefixLength("\\\\server\\a\\b\\c.txt"));
-        assertEquals(3, FilenameUtils.getPrefixLength( "\\\\a"));
 
         assertEquals(0, FilenameUtils.getPrefixLength("a/b/c.txt"));
         assertEquals(1, FilenameUtils.getPrefixLength("/a/b/c.txt"));
@@ -776,8 +779,8 @@ void testNormalize() {
         assertNull(FilenameUtils.normalize("1:"));
         assertNull(FilenameUtils.normalize("1:a"));
         assertNull(FilenameUtils.normalize("\\\\\\a\\b\\c.txt"));
+        assertEquals(SEP +  SEP + "a", FilenameUtils.normalize("\\\\a"));
 
-        assertEquals( SEP +  SEP + "a", FilenameUtils.normalize("\\\\a"));
         assertEquals("a" + SEP + "b" + SEP + "c.txt", FilenameUtils.normalize("a\\b/c.txt"));
         assertEquals("" + SEP + "a" + SEP + "b" + SEP + "c.txt", FilenameUtils.normalize("\\a\\b/c.txt"));
         assertEquals(DRIVE_C + SEP + "a" + SEP + "b" + SEP + "c.txt", FilenameUtils.normalize("C:\\a\\b/c.txt"));
@@ -916,7 +919,7 @@ void testNormalize() {
         assertNull(FilenameUtils.normalize("//server/../a"));
         assertNull(FilenameUtils.normalize("//server/.."));
         assertEquals(SEP + SEP + "server" + SEP + "", FilenameUtils.normalize("//server/"));
-        assertEquals( SEP +  SEP + "server", FilenameUtils.normalize("//server"));
+        assertEquals(SEP +  SEP + "server", FilenameUtils.normalize("//server"));
 
         assertEquals(SEP + SEP + "127.0.0.1" + SEP + "a" + SEP + "b" + SEP + "c.txt", FilenameUtils.normalize("\\\\127.0.0.1\\a\\b\\c.txt"));
         assertEquals(SEP + SEP + "::1" + SEP + "a" + SEP + "b" + SEP + "c.txt", FilenameUtils.normalize("\\\\::1\\a\\b\\c.txt"));
@@ -988,8 +991,8 @@ void testNormalizeNoEndSeparator() {
         assertNull(FilenameUtils.normalizeNoEndSeparator("1:"));
         assertNull(FilenameUtils.normalizeNoEndSeparator("1:a"));
         assertNull(FilenameUtils.normalizeNoEndSeparator("\\\\\\a\\b\\c.txt"));
+        assertEquals(SEP + SEP + "a", FilenameUtils.normalizeNoEndSeparator("\\\\a"));
 
-        assertEquals( SEP + SEP + "a", FilenameUtils.normalizeNoEndSeparator("\\\\a"));
         assertEquals("a" + SEP + "b" + SEP + "c.txt", FilenameUtils.normalizeNoEndSeparator("a\\b/c.txt"));
         assertEquals("" + SEP + "a" + SEP + "b" + SEP + "c.txt", FilenameUtils.normalizeNoEndSeparator("\\a\\b/c.txt"));
         assertEquals(DRIVE_C + SEP + "a" + SEP + "b" + SEP + "c.txt", FilenameUtils.normalizeNoEndSeparator("C:\\a\\b/c.txt"));
@@ -1129,7 +1132,7 @@ void testNormalizeNoEndSeparator() {
         assertNull(FilenameUtils.normalizeNoEndSeparator("//server/../a"));
         assertNull(FilenameUtils.normalizeNoEndSeparator("//server/.."));
         assertEquals(SEP + SEP + "server" + SEP + "", FilenameUtils.normalizeNoEndSeparator("//server/"));
-        assertEquals( SEP + SEP + "server", FilenameUtils.normalizeNoEndSeparator("//server"));
+        assertEquals(SEP + SEP + "server", FilenameUtils.normalizeNoEndSeparator("//server"));
     }
 
     @Test