mockit.Invocation Maven / Gradle / Ivy

/*
 * Copyright (c) 2006 JMockit developers
 * This file is subject to the terms of the MIT license (see LICENSE.txt).
 */
package mockit;

import java.lang.reflect.*;
import javax.annotation.*;

import mockit.internal.*;

/**
 * A context object representing the current invocation to a mocked or faked method/constructor, to be passed as the first
 * parameter of the corresponding delegate/fake method implementation.
 * 
 * With the Mocking API, this parameter can appear in delegate methods implemented in {@link Delegate} classes.
 * With the Faking API, it can appear in {@link Mock @Mock} methods.
 *
 * @see #getInvokedInstance()
 * @see #getInvokedArguments()
 * @see #getInvocationCount()
 * @see #getInvocationIndex()
 * @see #proceed(Object...)
 * @see Tutorial (mocking)
 * @see Tutorial (faking)
 */
public class Invocation
{
   @Nullable private final Object invokedInstance;
   @Nonnull private final Object[] invokedArguments;
   @Nonnegative private final int invocationCount;

   /**
    * For internal use only.
    */
   protected Invocation(@Nullable Object invokedInstance, @Nonnull Object[] invokedArguments, @Nonnegative int invocationCount) {
      this.invokedInstance = invokedInstance;
      this.invokedArguments = invokedArguments;
      this.invocationCount = invocationCount;
   }

   /**
    * Returns the instance on which the current invocation was made, or null for a static method invocation.
    */
   @Nullable
   public final  T getInvokedInstance() {
      // noinspection unchecked
      return (T) invokedInstance;
   }

   /**
    * Returns the Method or Constructor object corresponding to the target method or constructor, respectively.
    */
   @Nonnull
   public final  M getInvokedMember() {
      //noinspection unchecked,ClassReferencesSubclass
      return (M) ((BaseInvocation) this).getRealMember();
   }

   /**
    * Returns the actual argument values passed in the invocation to the target method/constructor.
    */
   @Nonnull
   public final Object[] getInvokedArguments() { return invokedArguments; }

   /**
    * Returns the current invocation count. The first invocation starts at 1 (one).
    */
   @Nonnegative
   public final int getInvocationCount() { return invocationCount; }

   /**
    * Returns the index for the current invocation. The first invocation starts at 0 (zero).
    * Note that this is equivalent to {@link #getInvocationCount()} - 1.
    */
   public final int getInvocationIndex() { return invocationCount - 1; }

   /**
    * Allows execution to proceed into the real implementation of the target method/constructor.
    * 

    * In the case of a method, the real implementation is executed with the argument values originally received or explicitly given as replacement.
    * Whatever comes out (either a return value or a thrown exception/error) becomes the result for this execution of the method.
    * 
    * In the case of a constructor, the real constructor implementation code which comes after the necessary call to "super" is
    * executed, using the original argument values; replacement arguments are not supported.
    * If the execution of said code throws an exception or error, it is propagated out to the caller of the target constructor.
    * Contrary to proceeding into a method, it's not possible to actually execute test code inside the delegate or fake method after proceeding into
    * the real constructor, nor to proceed into it more than once.
    *
    * @param replacementArguments the argument values to be passed to the real method, as replacement for the values received by the delegate or fake
    *                             method; if those received values should be passed without replacement, then this method should be called with no
    *                             values
    * @param  the return type of the target method
    *
    * @return the same value returned by the target method, if any
    *
    * @throws UnsupportedOperationException if attempting to proceed into a target method which does not belong to an
    * {@linkplain Injectable injectable mocked type} nor to a {@linkplain Expectations#Expectations(Object...) dynamic partially mocked type}, into a
    * native method, or into an interface or abstract method
    *
    * @see Tutorial
    */
   @Nullable
   public final  T proceed(@Nullable Object... replacementArguments) {
      //noinspection ClassReferencesSubclass
      return ((BaseInvocation) this).doProceed(replacementArguments);
   }
}