[TIMOB-26149] Android: Ti.Filesystem.File#getDirectoryListing() does not return null for file/non-existent directory

android/titanium/src/java/org/appcelerator/titanium/TiFileProxy.java

@@ -239,6 +239,9 @@ public boolean getHidden()
 	public String[] getDirectoryListing()
 	// clang-format on
 	{
+		if (!isDirectory()) {
+			return null;
+		}
 		List<String> dl = tbf.getDirectoryListing();
 		return dl != null ? dl.toArray(new String[0]) : null;
 	}

tests/Resources/ti.filesystem.file.addontest.js

@@ -0,0 +1,65 @@
+/*
+ * Appcelerator Titanium Mobile
+ * Copyright (c) 2011-Present by Appcelerator, Inc. All Rights Reserved.
+ * Licensed under the terms of the Apache Public License
+ * Please see the LICENSE included with this distribution for details.
+ */
+/* eslint-env mocha */
+/* global Ti */
+/* eslint no-unused-expressions: "off" */
+'use strict';
+var should = require('./utilities/assertions'); // eslint-disable-line no-unused-vars
+
+describe('Titanium.Filesystem.File', function () {
+	describe('#getDirectoryListing()', function () {
+		it('is a Function', function () {
+			var dir = Ti.Filesystem.getFile(Ti.Filesystem.resourcesDirectory);
+			should(dir.getDirectoryListing).be.a.Function;
+		});
+
+		it('returns Array of filenames for directory contents', function () {
+			var dir = Ti.Filesystem.getFile(Ti.Filesystem.resourcesDirectory),
+				files = dir.getDirectoryListing();
+			should(dir.exists()).be.true;
+			files.should.be.an.Array;
+			files.length.should.be.above(0);
+			files[0].should.be.a.String;
+		});
+
+		it('returns empty Array for empty directory', function () {
+			var emptyDir = Ti.Filesystem.getFile(Ti.Filesystem.applicationDataDirectory, 'emptyDir'),
+				result;
+			should(emptyDir).be.ok;
+			// remove it if it exists
+			if (emptyDir.exists()) {
+				should(emptyDir.deleteDirectory()).eql(true);
+			}
+			// create a fresh empty dir
+			should(emptyDir.createDirectory()).eql(true);
+			should(emptyDir.exists()).eql(true);
+			should(emptyDir.isFile()).eql(false);
+			should(emptyDir.isDirectory()).eql(true);
+
+			result = emptyDir.getDirectoryListing();
+			result.should.be.an.Array;
+			result.length.should.eql(0);
+		});
+
+		it('returns null for non-existent directory', function () {
+			var nonExistentDir = Ti.Filesystem.getFile('madeup');
+			var result = nonExistentDir.getDirectoryListing();
+			should(nonExistentDir).be.ok;
+			should(nonExistentDir.exists()).eql(false);
+			should(result).eql(null);
+		});
+
+		it('returns null for file', function () {
+			var file = Ti.Filesystem.getFile(Ti.Filesystem.resourcesDirectory, 'app.js');
+			var result = file.getDirectoryListing();
+			should(file).be.ok;
+			should(file.exists()).eql(true);
+			should(file.isFile()).eql(true);
+			should(result).eql(null);
+		});
+	});
+});