Add some basic unit tests

And update travis to run them

.travis.yml

@@ -21,4 +21,4 @@ before_install:
 #  - emulator -avd test -no-skin -no-audio -no-window &
 
 script:
-  - ./gradlew build
+  - ./gradlew clean build check

library/build.gradle

@@ -20,6 +20,8 @@ dependencies {
     compile 'com.android.support:appcompat-v7:22.2.0'
     compile 'com.android.support:support-v4:22.2.0'
     compile 'com.android.support:recyclerview-v7:22.1.1'
+
+    testCompile 'junit:junit:4.12'
 }
 
 publish {

library/src/test/java/com/nononsenseapps/filepicker/FilePickerFragmentTest.java

@@ -0,0 +1,70 @@
+package com.nononsenseapps.filepicker;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.io.File;
+
+import static org.junit.Assert.*;
+
+
+public class FilePickerFragmentTest {
+
+    private static FilePickerFragment fragment;
+    private static File somePath;
+    private static String someName;
+
+    @BeforeClass
+    public static void runBeforeClass() {
+        // Runs ONCE, before all tests
+        fragment = new FilePickerFragment();
+        someName = "FileName";
+        somePath = new File("/path/to/some/" + someName);
+    }
+
+    @AfterClass
+    public static void runAfterClass() {
+    }
+
+    @Test
+    public void testGetName() throws Exception {
+        assertEquals(someName, fragment.getName(somePath));
+    }
+
+    @Test
+    public void testGetParent() throws Exception {
+        assertEquals("/path/to/some", fragment.getParent(somePath).getPath());
+
+        // Self
+        assertEquals(fragment.getRoot().getPath(), fragment.getParent(new File("/path")).getPath());
+        assertEquals(fragment.getRoot().getPath(), fragment.getParent(new File("/")).getPath());
+    }
+
+    @Test
+    public void testGetPath() throws Exception {
+        assertEquals("/some/path", fragment.getPath("/some/path").getPath());
+    }
+
+    @Test
+    public void testGetFullPath() throws Exception {
+        assertEquals("/some/path", fragment.getFullPath(new File("/some/path")));
+    }
+
+    @Test
+    public void testGetRoot() throws Exception {
+        assertEquals("/", fragment.getRoot().getPath());
+    }
+
+    @Test
+    public void testCompareFiles() throws Exception {
+        assertEquals(0, fragment.compareFiles(new File("/A/A"), new File("/A/A")));
+        assertEquals(-1, fragment.compareFiles(new File("/A/A"), new File("/A/B")));
+        assertEquals(1, fragment.compareFiles(new File("/A/B"), new File("/A/A")));
+
+        // Dir is assumed to be the same
+        assertEquals(1, fragment.compareFiles(new File("/A/B"), new File("/B/A")));
+        assertEquals(-1, fragment.compareFiles(new File("/B/A"), new File("/A/B")));
+        assertEquals(0, fragment.compareFiles(new File("/A/B"), new File("/B/B")));
+    }
+}