Adds extra test and minor cleanups.

Author: andrenpaes

jooby-servlet/src/main/java/org/jooby/servlet/ServletServletRequest.java

@@ -25,6 +25,7 @@
 import java.net.URLDecoder;
 import java.util.*;
 import java.util.concurrent.Executor;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 
 import javax.servlet.ServletException;
@@ -121,7 +122,8 @@ public Map<String, Object> attributes() {
     if (!attributeNames.hasMoreElements()) {
       return Collections.emptyMap();
     }
-    return Collections.list(attributeNames).stream().collect(Collectors.toMap(name -> name, name -> req.getAttribute(name)));
+    return Collections.list(attributeNames).stream()
+        .collect(Collectors.toMap(Function.identity(), name -> req.getAttribute(name)));
   }
 
   @Override

jooby-servlet/src/test/java/org/jooby/servlet/ServletServletRequestTest.java

@@ -154,9 +154,9 @@ public void noparams() throws IOException, Exception {
 
   @Test
   public void attributes() throws Exception {
-      String tmpdir = System.getProperty("java.io.tmpdir");
-      UUID serverAttribute = UUID.randomUUID();
-      new MockUnit(HttpServletRequest.class)
+    String tmpdir = System.getProperty("java.io.tmpdir");
+    final UUID serverAttribute = UUID.randomUUID();
+    new MockUnit(HttpServletRequest.class)
         .expect(unit -> {
           HttpServletRequest req = unit.get(HttpServletRequest.class);
           expect(req.getContentType()).andReturn("text/html");
@@ -173,6 +173,24 @@ public void attributes() throws Exception {
 
   }
 
+  @Test
+  public void emptyAttributes() throws Exception {
+    String tmpdir = System.getProperty("java.io.tmpdir");
+    new MockUnit(HttpServletRequest.class)
+        .expect(unit -> {
+          HttpServletRequest req = unit.get(HttpServletRequest.class);
+          expect(req.getContentType()).andReturn("text/html");
+          expect(req.getPathInfo()).andReturn("/");
+          expect(req.getAttributeNames()).andReturn(Collections.emptyEnumeration());
+        })
+        .run(unit -> {
+          assertEquals(Collections.emptyMap(),
+              new ServletServletRequest(unit.get(HttpServletRequest.class), tmpdir)
+                  .attributes());
+        });
+
+  }
+
   @Test(expected = IOException.class)
   public void filesFailure() throws IOException, Exception {
     String tmpdir = System.getProperty("java.io.tmpdir");