add unittest for ExtensionFileFilter

Author: chewiebug

src/main/java/com/tagtraum/perf/gcviewer/view/util/ExtensionFileFilter.java

@@ -1,7 +1,7 @@
 package com.tagtraum.perf.gcviewer.view.util;
 
-import javax.swing.filechooser.FileFilter;
 import java.io.File;
+import javax.swing.filechooser.FileFilter;
 
 /**
  * ExtensionFileFilter.
@@ -22,7 +22,6 @@ public ExtensionFileFilter(String extension) {
     }
 
     public boolean accept(File f) {
-        // TODO: Can probably be refactored; seems to be the same as in Export class
         try {
             return f.isDirectory() || f.toString().toLowerCase().endsWith("." + extension);
         }

src/test/java/com/tagtraum/perf/gcviewer/view/util/ExtensionFileFilterTest.java

@@ -0,0 +1,48 @@
+package com.tagtraum.perf.gcviewer.view.util;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+
+import java.io.File;
+
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * @author <a href="mailto:gcviewer@gmx.ch">Joerg Wuethrich</a>
+ * <p>created on: 01.08.2018</p>
+ */
+public class ExtensionFileFilterTest {
+
+    private ExtensionFileFilter extensionFileFilter;
+
+    @Before
+    public void setup() {
+        extensionFileFilter = new ExtensionFileFilter("txt");
+    }
+
+    @Test
+    public void description() {
+        assertThat("extension", extensionFileFilter.getDescription(), equalTo("*.txt"));
+    }
+
+    @Test
+    public void acceptFalse() {
+        boolean doesAccept = extensionFileFilter.accept(new File("dummy-file-name"));
+
+        assertThat("accepts", doesAccept, is(false));
+    }
+
+    @Test
+    public void acceptTrue() {
+        boolean doesAccept = extensionFileFilter.accept(new File("dummy-file-name.txt"));
+
+        assertThat("accepts", doesAccept, is(true));
+    }
+
+    @Test
+    public void acceptNull() {
+        assertThat("null parameter", extensionFileFilter.accept(null), is(false));
+    }
+}