fix file names and add file generator tests

src/main/java/ic/doc/web/HtmlConverter.java

@@ -34,7 +34,8 @@ public class HtmlConverter {
         }
 
         try {
-            String pdfFilePath = mdFile.getCanonicalPath() + ".pdf";
+            String canocialPath = mdFile.getCanonicalPath();
+            String pdfFilePath = canocialPath.substring(0, canocialPath.length() - 3) + ".pdf";
             new ProcessBuilder("pandoc", mdFile.getCanonicalPath(), "-o", pdfFilePath)
                     .start().waitFor();
 

src/test/java/ic/doc/FileGenerateTest.java

+package ic.doc;
+
+import ic.doc.web.HtmlConverter;
+import org.junit.Test;
+
+import static org.junit.Assert.assertTrue;
+
+public class FileGenerateTest {
+
+  @Test
+  public void generatesMdFile() throws Exception {
+    assertTrue(HtmlConverter.stringToMdFile("tony", "test") != null);
+  }
+
+  @Test
+  public void generatesPdfFile() throws Exception {
+    assertTrue(HtmlConverter.stringToPdfFile("tony", "test") != null);
+  }
+
+  @Test
+  public void reasonableNameForMdFile() throws Exception {
+    assertTrue(
+        HtmlConverter.stringToMdFile("konstantinos", "test")
+            .getName()
+            .matches("konstantinos[0-9]+.md"));
+  }
+
+  @Test
+  public void reasonableNameForPdfFile() throws Exception {
+    assertTrue(HtmlConverter.stringToPdfFile("tony", "test")
+              .getName()
+              .matches("tony[0-9]+.pdf"));
+  }
+}