Add unit test for new behavior

pmd-javascript/src/test/java/net/sourceforge/pmd/cpd/CPDCommandLineInterfaceTest.java

@@ -0,0 +1,56 @@
+/**
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+package net.sourceforge.pmd.cpd;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import java.io.UnsupportedEncodingException;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+public class CPDCommandLineInterfaceTest {
+    private ByteArrayOutputStream bufferStdout;
+    private PrintStream originalStdout;
+    private PrintStream originalStderr;
+
+    @Before
+    public void setup() throws UnsupportedEncodingException {
+        originalStdout = System.out;
+        originalStderr = System.err;
+        bufferStdout = new ByteArrayOutputStream();
+        System.setOut(new PrintStream(bufferStdout, false, "UTF-8"));
+        System.setErr(System.out);
+    }
+
+    @After
+    public void teardown() {
+        System.setOut(originalStdout);
+        System.setErr(originalStderr);
+    }
+
+    @Test
+    public void shouldFindDuplicatesWithDifferentFileExtensions() throws Exception {
+        runCPD("--minimum-tokens", "5", "--language", "js", "--files", "src/test/resources/net/sourceforge/pmd/cpd/ts/File1.ts",
+                "src/test/resources/net/sourceforge/pmd/cpd/ts/File2.ts");
+
+        String out = bufferStdout.toString("UTF-8");
+        Assert.assertTrue(out.contains("Found a 9 line (30 tokens) duplication in the following files"));
+    }
+
+    @Test
+    public void shouldFindNoDuplicatesWithDifferentFileExtensions() throws Exception {
+        runCPD("--minimum-tokens", "5", "--language", "js", "--files", "src/test/resources/net/sourceforge/pmd/cpd/ts/");
+
+        String out = bufferStdout.toString("UTF-8");
+        Assert.assertTrue(out.isEmpty());
+    }
+    
+    private void runCPD(String ... args) {
+        System.setProperty(CPDCommandLineInterface.NO_EXIT_AFTER_RUN, "true");
+        CPD.main(args);
+    }
+}

pmd-javascript/src/test/resources/net/sourceforge/pmd/cpd/ts/File1.ts

@@ -0,0 +1,9 @@
+(function(){
+
+var x = 1;
+var y = 2;
+var z = 3;
+window.alert('Test');
+
+
+})();

pmd-javascript/src/test/resources/net/sourceforge/pmd/cpd/ts/File2.ts

@@ -0,0 +1,9 @@
+(function(){
+
+var x = 1;
+var y = 2;
+var z = 3;
+window.alert('Test');
+
+
+})();