Work around Windows file deletion problems

See http://forum.imagej.net/t/11888/10

Author: ctrueden

src/test/java/org/scijava/io/handle/FileHandleTest.java

@@ -46,6 +46,7 @@
 import org.scijava.Context;
 import org.scijava.io.location.FileLocation;
 import org.scijava.io.location.Location;
+import org.scijava.util.PlatformUtils;
 
 /**
  * Tests {@link FileHandle}.
@@ -75,21 +76,22 @@ public void testExists() throws IOException {
 
 		final File nonExistentFile = //
 			File.createTempFile("FileHandleTest", "nonexistent-file");
-		assertTrue(nonExistentFile.delete());
-		assertFalse(nonExistentFile.exists());
+		final boolean deleted = delete(nonExistentFile);
 
 		final FileLocation loc = new FileLocation(nonExistentFile);
 		final DataHandle<?> handle = dhs.create(loc);
 		assertTrue(handle instanceof FileHandle);
-		assertFalse(handle.exists());
-		assertEquals(-1, handle.length());
+		if (deleted) {
+			assertFalse(handle.exists());
+			assertEquals(-1, handle.length());
+		}
 
 		handle.writeBoolean(true);
 		assertTrue(handle.exists());
 		assertEquals(1, handle.length());
 
 		// Clean up.
-		assertTrue(nonExistentFile.delete());
+		delete(nonExistentFile);
 	}
 
 	@Test
@@ -118,8 +120,7 @@ public void testNotCreatedByRead() throws IOException {
 		final File nonExistentFile = //
 			File.createTempFile("FileHandleTest", "none xistent file");
 		final URI uri = nonExistentFile.toURI();
-		assertTrue(nonExistentFile.delete());
-		assertFalse(nonExistentFile.exists());
+		delete(nonExistentFile);
 
 		final FileLocation loc = new FileLocation(uri);
 		try (final DataHandle<?> handle = dhs.create(loc)) {
@@ -133,4 +134,15 @@ public void testNotCreatedByRead() throws IOException {
 		assertFalse(nonExistentFile.exists());
 		// reading from the non-existing file should not create it!
 	}
+
+	/** A workaround for Windows being bad at deleting files. */
+	private boolean delete(final File file) {
+		final boolean success = file.delete();
+		if (!success) file.deleteOnExit();
+		if (!PlatformUtils.isWindows()) {
+			assertTrue(success);
+			assertFalse(file.exists());
+		}
+		return success;
+	}
 }