add simplified ArgumentCaptor support

Author: angryziber

mockito-kotlin/src/main/kotlin/com/nhaarman/mockito_kotlin/Mockito.kt

@@ -25,6 +25,7 @@
 
 package com.nhaarman.mockito_kotlin
 
+import org.mockito.ArgumentCaptor
 import org.mockito.Mockito
 import org.mockito.stubbing.Answer
 import org.mockito.stubbing.Stubber
@@ -55,6 +56,9 @@ fun doNothing() = Mockito.doNothing()
 
 fun <T> Stubber.whenever(mock: T) = `when`(mock)
 
+inline fun <reified T : Any> argumentCaptor() = ArgumentCaptor.forClass(T::class.java)
+inline fun <reified T : Any> capture(captor: ArgumentCaptor<T>): T = captor.capture() ?: createInstance<T>()
+
 inline fun <reified T : Any> eq(value: T) = Mockito.eq(value) ?: createInstance<T>()
 inline fun <reified T : Any> anyArray(): Array<T> = Mockito.any(Array<T>::class.java) ?: arrayOf()
 inline fun <reified T : Any> any() = Mockito.any(T::class.java) ?: createInstance<T>()

mockito-kotlin/src/test/kotlin/ArgumentCaptorTest.kt

@@ -0,0 +1,20 @@
+import com.nhaarman.mockito_kotlin.argumentCaptor
+import com.nhaarman.mockito_kotlin.mock
+import com.nhaarman.mockito_kotlin.verify
+import com.nhaarman.expect.expect
+import com.nhaarman.mockito_kotlin.capture
+import org.junit.Test
+import java.util.*
+
+class ArgumentCaptorTest {
+    @Test
+    fun captor() {
+        val date: Date = mock()
+        val time = argumentCaptor<Long>()
+
+        date.time = 5L
+
+        verify(date).time = capture(time)
+        expect(time.value).toBe(5L)
+    }
+}