Github user lfrancke commented on a diff in the pull request:
https://github.com/apache/nifi/pull/2872#discussion_r201495972
--- Diff:
nifi-testharness/src/test/java/org/apache/nifi/testharness/samples/TestUtils.java
---
@@ -0,0 +1,47 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+
+package org.apache.nifi.testharness.samples;
+
+import java.io.File;
+
+final class TestUtils {
+
+ private TestUtils() {
+ // no instances allowed
+ }
+
+ static File getBinaryDistributionZipFile(File
binaryDistributionZipDir) {
+
+ File[] files = binaryDistributionZipDir.listFiles((dir, name) ->
--- End diff --
This can return `null` which makes the next `if` statement fail with a NPE.
I think the condition can be extended to
```
if (files == null || files.length == 0)
```
---
