From a17a01047f08317640ae63f27b20c482a2533ea4 Mon Sep 17 00:00:00 2001
From: Michal Kordas <kordas.michal@gmail.com>
Date: Wed, 19 Aug 2015 20:59:47 +0200
Subject: [PATCH] Return unmodifiable collection from class in test code. #1555

Fixes `ReturnOfCollectionField` inspection violations in test code.

Description:
>Reports any attempt to return an array or Collection field from a method. Since the array or Collection may have its contents modified by the calling method, this construct may result in an object having its state modified unexpectedly. While occasionally useful for performance reasons, this construct is inherently bug-prone.
---
 .../com/google/checkstyle/test/base/ConfigurationBuilder.java  | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/it/java/com/google/checkstyle/test/base/ConfigurationBuilder.java b/src/it/java/com/google/checkstyle/test/base/ConfigurationBuilder.java
index b5d379633..f16c4ac21 100644
--- a/src/it/java/com/google/checkstyle/test/base/ConfigurationBuilder.java
+++ b/src/it/java/com/google/checkstyle/test/base/ConfigurationBuilder.java
@@ -6,6 +6,7 @@ import java.io.FileReader;
 import java.io.IOException;
 import java.net.URL;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Properties;
 import java.util.regex.Pattern;
@@ -95,7 +96,7 @@ public class ConfigurationBuilder extends BaseCheckTestSupport {
 	}
 
 	public List<File> getFiles() {
-            return files;
+            return Collections.unmodifiableList(files);
 	}
 
 	public Integer[] getLinesWithWarn(String aFileName) throws IOException {