Add a few assertions.
MODIFY
src/test/java/org/apache/commons/io/FileUtilsTest.java
src/test/java/org/apache/commons/io/FileUtilsTest.java
@@ -1623,6 +1623,7 @@ public void testIsDirectory() throws IOException {
final Path tempDir = Files.createTempDirectory(getClass().getCanonicalName());
final File tempDirAsFile = tempDir.toFile();
+ assertTrue(FileUtils.isDirectory(tempDirAsFile));
Files.delete(tempDir);
assertFalse(FileUtils.isDirectory(tempDirAsFile));
}

MODIFY
src/test/java/org/apache/commons/io/file/PathUtilsTest.java
src/test/java/org/apache/commons/io/file/PathUtilsTest.java
@@ -229,6 +229,7 @@ public void testIsDirectory() throws IOException {
assertFalse(PathUtils.isDirectory(testFile1));
final Path tempDir = Files.createTempDirectory(getClass().getCanonicalName());
+ assertTrue(PathUtils.isDirectory(tempDir));
Files.delete(tempDir);
assertFalse(PathUtils.isDirectory(tempDir));
}

Add a few assertions.