Added ability for the transcoder to determine if a video file is open in another program to avoid trying to transcode/remove a partially written file; reworked the main transcode loop to handle one file at a time instead of archiving everything, then transcoding, then cleanup

src/test/java/tech/bitgoblin/io/IOUtilsTest.java

@@ -1,15 +1,21 @@
 package tech.bitgoblin.io;
 
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 import org.junit.AfterClass;
+import org.junit.BeforeClass;
 import org.junit.Test;
 
 import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.RandomAccessFile;
 
 public class IOUtilsTest {
 
   private static String testDir = "test-temp";
+  private static String testFile = "test.txt";
 
   @Test
   public void shouldCreateDirectory() {
@@ -28,9 +34,30 @@ public class IOUtilsTest {
     IOUtils.resolveTilda("~test");
   }
 
+  @Test
+  public void fileShouldBeLocked() throws IOException {
+    RandomAccessFile raf = new RandomAccessFile(testFile, "rw");
+    assertTrue(IOUtils.isFileLocked(new File(testFile)));
+  }
+
+  @Test
+  public void fileShouldNotBeLocked() throws IOException {
+    RandomAccessFile raf = new RandomAccessFile("test.txt", "rw");
+    raf.close();
+    assertFalse(IOUtils.isFileLocked(new File(testFile)));
+  }
+
+  @BeforeClass
+  // ensure that test files are created before running tests
+  public static void setup() throws IOException {
+    new File(testFile).createNewFile();
+  }
+
   @AfterClass
+  // ensure test files are cleaned up from the environment
   public static void cleanup() {
     new File(testDir).delete();
+    new File(testFile).delete();
   }
 
 }