Use EqualsVerifier to test CSVFilter. #1088

pom.xml

@@ -889,7 +889,6 @@
           <regex><pattern>.*.checks.whitespace.WhitespaceAroundCheck</pattern><branchRate>96</branchRate><lineRate>98</lineRate></regex>
 
 
-          <regex><pattern>.*.filters.CSVFilter</pattern><branchRate>100</branchRate><lineRate>93</lineRate></regex>
           <regex><pattern>.*.filters.IntMatchFilter</pattern><branchRate>100</branchRate><lineRate>90</lineRate></regex>
           <regex><pattern>.*.filters.IntRangeFilter</pattern><branchRate>100</branchRate><lineRate>90</lineRate></regex>
           <regex><pattern>.*.filters.SuppressElement</pattern><branchRate>69</branchRate><lineRate>78</lineRate></regex>

src/main/java/com/puppycrawl/tools/checkstyle/filters/CSVFilter.java

@@ -20,6 +20,8 @@
 package com.puppycrawl.tools.checkstyle.filters;
 
 import com.google.common.collect.Sets;
+
+import java.util.Objects;
 import java.util.Set;
 import java.util.StringTokenizer;
 
@@ -96,21 +98,19 @@ class CSVFilter implements IntFilter {
     }
 
     @Override
-    public String toString() {
-        return filters.toString();
+    public boolean equals(Object object) {
+        if (this == object) {
+            return true;
+        }
+        if (object == null || getClass() != object.getClass()) {
+            return false;
+        }
+        final CSVFilter csvFilter = (CSVFilter) object;
+        return Objects.equals(filters, csvFilter.filters);
     }
 
     @Override
     public int hashCode() {
-        return filters.hashCode();
-    }
-
-    @Override
-    public boolean equals(Object object) {
-        if (object instanceof CSVFilter) {
-            final CSVFilter other = (CSVFilter) object;
-            return this.filters.equals(other.filters);
-        }
-        return false;
+        return Objects.hash(filters);
     }
 }

src/test/java/com/puppycrawl/tools/checkstyle/filters/CSVFilterTest.java

@@ -21,6 +21,8 @@ package com.puppycrawl.tools.checkstyle.filters;
 
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+
+import nl.jqno.equalsverifier.EqualsVerifier;
 import org.junit.Test;
 
 /** Tests CSVFilter */
@@ -72,4 +74,9 @@ public class CSVFilterTest {
         assertFalse("greater than", filter.accept(Integer.valueOf(3)));
         assertTrue("equal 10", filter.accept(Integer.valueOf(10)));
     }
+
+    @Test
+    public void testEqualsAndHashCode() {
+        EqualsVerifier.forClass(CSVFilter.class).usingGetClass().verify();
+    }
 }