Index: src/main/groovy/mock/interceptor/MockFor.groovy
===================================================================
--- src/main/groovy/mock/interceptor/MockFor.groovy	(revision 19142)
+++ src/main/groovy/mock/interceptor/MockFor.groovy	Wed Feb 03 21:07:06 EST 2010
@@ -19,7 +19,7 @@
 
 /**
  *   Facade over the Mocking details.
- *   A Mock's expectation is always sequence dependent and it's use always ends with a verify().
+ *   A Mock's expectation is always sequence dependent and it's use automatically ends with a verify().
  *
  *   @see StubFor
  *   @author Dierk Koenig
@@ -33,9 +33,12 @@
     Map instanceExpectations = [:]
     Class clazz
 
-    MockFor(Class clazz) {
+    MockFor(Class clazz, boolean interceptConstruction=false) {
+        if (interceptConstruction && !GroovyObject.isAssignableFrom(clazz)) {
+            throw new IllegalArgumentException("MockFor with constructor interception enabled is only allowed for Groovy objects but found: " + clazz.name)
+        }
         this.clazz = clazz
-        proxy = MockProxyMetaClass.make(clazz)
+        proxy = MockProxyMetaClass.make(clazz, interceptConstruction)
         demand = new Demand()
         expect = new StrictExpectation(demand)
         proxy.interceptor = new MockInterceptor(expectation: expect)
Index: src/main/groovy/mock/interceptor/MockProxyMetaClass.java
===================================================================
--- src/main/groovy/mock/interceptor/MockProxyMetaClass.java	(revision 19160)
+++ src/main/groovy/mock/interceptor/MockProxyMetaClass.java	Wed Feb 03 21:08:34 EST 2010
@@ -28,20 +28,37 @@
 
 public class MockProxyMetaClass extends ProxyMetaClass {
 
+    public final boolean interceptConstruction;
+
     /**
      * @param adaptee the MetaClass to decorate with interceptability
      */
     public MockProxyMetaClass(MetaClassRegistry registry, Class theClass, MetaClass adaptee) throws IntrospectionException {
+        this(registry, theClass, adaptee, false);
+    }
+
+    /**
+     * @param adaptee the MetaClass to decorate with interceptability
+     */
+    public MockProxyMetaClass(MetaClassRegistry registry, Class theClass, MetaClass adaptee, boolean interceptConstruction) throws IntrospectionException {
         super(registry, theClass, adaptee);
+        this.interceptConstruction = interceptConstruction;
     }
 
     /**
      * convenience factory method for the most usual case.
      */
     public static MockProxyMetaClass make(Class theClass) throws IntrospectionException {
+        return make(theClass, false);
+    }
+
+    /**
+     * convenience factory method allowing interceptConstruction to be set.
+     */
+    public static MockProxyMetaClass make(Class theClass, boolean interceptConstruction) throws IntrospectionException {
         MetaClassRegistry metaRegistry = GroovySystem.getMetaClassRegistry();
         MetaClass meta = metaRegistry.getMetaClass(theClass);
-        return new MockProxyMetaClass(metaRegistry, theClass, meta);
+        return new MockProxyMetaClass(metaRegistry, theClass, meta, interceptConstruction);
     }
 
     public Object invokeMethod(final Object object, final String methodName, final Object[] arguments) {
@@ -83,8 +100,18 @@
 
     /**
      * Unlike general impl in superclass, ctors are not intercepted but relayed
+     * unless interceptConstruction is set.
      */
     public Object invokeConstructor(final Object[] arguments) {
+        if (interceptConstruction && null == interceptor)
+            throw new RuntimeException("cannot invoke constructor without interceptor");
+
+        if (interceptConstruction) {
+            GroovyObject newInstance = (GroovyObject) interceptor.beforeInvoke(null, getTheClass().getSimpleName(), arguments);
+            newInstance.setMetaClass(this);
+            return newInstance;
+        }
+
         return adaptee.invokeConstructor(arguments);
     }
 
Index: src/main/groovy/mock/interceptor/StubFor.groovy
===================================================================
--- src/main/groovy/mock/interceptor/StubFor.groovy	(revision 19142)
+++ src/main/groovy/mock/interceptor/StubFor.groovy	Wed Feb 03 21:07:06 EST 2010
@@ -33,9 +33,12 @@
     Map instanceExpectations = [:]
     Class clazz
 
-    StubFor(Class clazz) {
+    StubFor(Class clazz, boolean interceptConstruction=false) {
+        if (interceptConstruction && !GroovyObject.isAssignableFrom(clazz)) {
+            throw new IllegalArgumentException("StubFor with constructor interception enabled is only allowed for Groovy objects but found: " + clazz.name)
+        }
         this.clazz = clazz
-        proxy = MockProxyMetaClass.make(clazz)
+        proxy = MockProxyMetaClass.make(clazz, interceptConstruction)
         demand = new Demand()
         expect = new LooseExpectation(demand)
         proxy.interceptor = new MockInterceptor(expectation: expect)