ROASTER-51: Improved parameter naming algorithm

api/src/main/java/org/jboss/forge/roaster/model/util/Methods.java

@@ -50,4 +50,44 @@ public static MethodSource<?>[] addInheritedAbstractMethods(final Class<?> sourc
       return methods.toArray(new MethodSource<?>[methods.size()]);
    }
 
+   /**
+    * Generate the parameter names of a given {@link Method}
+    */
+   public static String[] generateParameterNames(Class<?>[] parameterTypes)
+   {
+      List<String> parameterNames = new ArrayList<String>();
+      for (Class<?> paramType : parameterTypes)
+      {
+         // Check if we haven't already used it.
+         String name = toParamName(paramType.getSimpleName());
+         String paramName = name;
+         int idx = 1;
+         while (parameterNames.contains(paramName))
+         {
+            paramName = name + idx++;
+         }
+         parameterNames.add(paramName);
+      }
+      return parameterNames.toArray(new String[parameterNames.size()]);
+   }
+
+   static String toParamName(String type)
+   {
+      StringBuilder name = new StringBuilder(type);
+      int i;
+      for (i = 0; i < name.length(); i++)
+      {
+         if (!Character.isUpperCase(name.charAt(i)))
+         {
+            // Go back one index
+            i--;
+            break;
+         }
+      }
+      if (i == 0)
+         name.setCharAt(0, Character.toLowerCase(name.charAt(0)));
+      else if (i > 0)
+         name.replace(0, i, name.substring(0, i).toLowerCase());
+      return name.toString();
+   }
 }

api/src/test/java/org/jboss/forge/roaster/model/util/MethodsTest.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2015 Red Hat, Inc. and/or its affiliates.
+ *
+ * Licensed under the Eclipse Public License version 1.0, available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.jboss.forge.roaster.model.util;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+
+import java.awt.List;
+import java.util.Arrays;
+import java.util.Map;
+
+import org.hamcrest.CoreMatchers;
+import org.junit.Test;
+
+/**
+ *
+ * @author <a href="mailto:ggastald@redhat.com">George Gastaldi</a>
+ */
+public class MethodsTest
+{
+
+   @Test
+   public void testParamNameSingleUpperCase()
+   {
+      assertEquals("facesContext", Methods.toParamName("FacesContext"));
+   }
+
+   @Test
+   public void testParamNameMultipleUpperCase()
+   {
+      assertEquals("uiComponent", Methods.toParamName("UIComponent"));
+   }
+
+   @Test
+   public void testParamNameAllLowerCase()
+   {
+      assertEquals("myclass", Methods.toParamName("myclass"));
+   }
+
+   @Test
+   public void testParametersSameTypes()
+   {
+      String[] paramNames = Methods.generateParameterNames(new Class[] { List.class, List.class });
+      assertThat(Arrays.asList(paramNames), CoreMatchers.hasItems("list", "list1"));
+   }
+
+   @Test
+   public void testParametersDifferentTypes()
+   {
+      String[] paramNames = Methods.generateParameterNames(new Class[] { Map.class, List.class });
+      assertThat(Arrays.asList(paramNames), CoreMatchers.hasItems("map", "list"));
+   }
+
+}

impl/src/main/java/org/jboss/forge/roaster/model/impl/MethodImpl.java

@@ -41,6 +41,7 @@
 import org.jboss.forge.roaster.model.source.MethodSource;
 import org.jboss.forge.roaster.model.source.ParameterSource;
 import org.jboss.forge.roaster.model.source.TypeVariableSource;
+import org.jboss.forge.roaster.model.util.Methods;
 import org.jboss.forge.roaster.model.util.Strings;
 import org.jboss.forge.roaster.model.util.Types;
 
@@ -109,9 +110,11 @@ else if (Modifier.isPrivate(mod))
       // Set method name
       setName(reflectMethod.getName());
       // Set method parameters
-      for (Class<?> paramType : reflectMethod.getParameterTypes())
+      Class<?>[] paramTypes = reflectMethod.getParameterTypes();
+      String[] paramNames = Methods.generateParameterNames(paramTypes);
+      for (int i = 0; i < paramTypes.length; i++)
       {
-         addParameter(paramType, "arg" + method.parameters().size());
+         addParameter(paramTypes[i], paramNames[i]);
       }
       // Set method body
       {