Add support for destructured parameters in answers (#512)

Author: Osguima3

mockito-kotlin/src/main/kotlin/org/mockito/kotlin/KInvocationOnMock.kt

@@ -0,0 +1,39 @@
+/*
+ * The MIT License
+ *
+ * Copyright (c) 2018 Niek Haarman
+ * Copyright (c) 2007 Mockito contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package org.mockito.kotlin
+
+import org.mockito.invocation.InvocationOnMock
+
+class KInvocationOnMock(
+    private val invocationOnMock: InvocationOnMock
+) : InvocationOnMock by invocationOnMock {
+
+    operator fun <T> component1(): T = invocationOnMock.getArgument(0)
+    operator fun <T> component2(): T = invocationOnMock.getArgument(1)
+    operator fun <T> component3(): T = invocationOnMock.getArgument(2)
+    operator fun <T> component4(): T = invocationOnMock.getArgument(3)
+    operator fun <T> component5(): T = invocationOnMock.getArgument(4)
+}

mockito-kotlin/src/main/kotlin/org/mockito/kotlin/OngoingStubbing.kt

@@ -28,7 +28,7 @@ package org.mockito.kotlin
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.runBlocking
 import org.mockito.Mockito
-import org.mockito.invocation.InvocationOnMock
+import org.mockito.kotlin.internal.KAnswer
 import org.mockito.kotlin.internal.SuspendableAnswer
 import org.mockito.stubbing.Answer
 import org.mockito.stubbing.OngoingStubbing
@@ -132,10 +132,10 @@ infix fun <T> OngoingStubbing<T>.doAnswer(answer: Answer<*>): OngoingStubbing<T>
 /**
  * Sets a generic Answer for the method using a lambda.
  */
-infix fun <T> OngoingStubbing<T>.doAnswer(answer: (InvocationOnMock) -> T?): OngoingStubbing<T> {
-    return thenAnswer(answer)
+infix fun <T> OngoingStubbing<T>.doAnswer(answer: (KInvocationOnMock) -> T?): OngoingStubbing<T> {
+    return thenAnswer(KAnswer(answer))
 }
 
-infix fun <T> OngoingStubbing<T>.doSuspendableAnswer(answer: suspend (InvocationOnMock) -> T?): OngoingStubbing<T> {
+infix fun <T> OngoingStubbing<T>.doSuspendableAnswer(answer: suspend (KInvocationOnMock) -> T?): OngoingStubbing<T> {
     return thenAnswer(SuspendableAnswer(answer))
 }

mockito-kotlin/src/main/kotlin/org/mockito/kotlin/internal/KAnswer.kt

@@ -0,0 +1,42 @@
+/*
+ * The MIT License
+ *
+ * Copyright (c) 2018 Niek Haarman
+ * Copyright (c) 2007 Mockito contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package org.mockito.kotlin.internal
+
+import org.mockito.invocation.InvocationOnMock
+import org.mockito.kotlin.KInvocationOnMock
+import org.mockito.stubbing.Answer
+
+/**
+ * This class wraps destructuring lambda into [Answer]
+ */
+@Suppress("UNCHECKED_CAST")
+internal class KAnswer<T>(
+    private val body: (KInvocationOnMock) -> T?
+) : Answer<T> {
+    override fun answer(invocation: InvocationOnMock): T {
+        return body(KInvocationOnMock(invocation)) as T
+    }
+}

mockito-kotlin/src/main/kotlin/org/mockito/kotlin/internal/SuspendableAnswer.kt

@@ -27,6 +27,7 @@ package org.mockito.kotlin.internal
 
 import org.mockito.internal.invocation.InterceptedInvocation
 import org.mockito.invocation.InvocationOnMock
+import org.mockito.kotlin.KInvocationOnMock
 import org.mockito.stubbing.Answer
 import kotlin.coroutines.Continuation
 import kotlin.coroutines.intrinsics.startCoroutineUninterceptedOrReturn
@@ -36,7 +37,7 @@ import kotlin.coroutines.intrinsics.startCoroutineUninterceptedOrReturn
  */
 @Suppress("UNCHECKED_CAST")
 internal class SuspendableAnswer<T>(
-    private val body: suspend (InvocationOnMock) -> T?
+    private val body: suspend (KInvocationOnMock) -> T?
 ) : Answer<T> {
     override fun answer(invocation: InvocationOnMock?): T {
         //all suspend functions/lambdas has Continuation as the last argument.
@@ -45,6 +46,6 @@ internal class SuspendableAnswer<T>(
         val continuation = rawInvocation.rawArguments.last() as Continuation<T?>
 
         // https://youtrack.jetbrains.com/issue/KT-33766#focus=Comments-27-3707299.0-0
-        return body.startCoroutineUninterceptedOrReturn(invocation, continuation) as T
+        return body.startCoroutineUninterceptedOrReturn(KInvocationOnMock(invocation), continuation) as T
     }
 }

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

@@ -3,10 +3,6 @@
 package test
 
 import com.nhaarman.expect.expect
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.delay
-import kotlinx.coroutines.runBlocking
-import kotlinx.coroutines.withContext
 import kotlinx.coroutines.*
 import kotlinx.coroutines.channels.actor
 import org.junit.Assert.assertEquals
@@ -265,6 +261,17 @@ class CoroutinesTest {
         assertEquals(42, fixture.suspending())
     }
 
+    @Test
+    fun answerWithSuspendFunctionWithDestructuredArgs() = runBlocking {
+        val fixture: SomeInterface = mock()
+
+        whenever(fixture.suspendingWithArg(any())).doSuspendableAnswer { (i: Int) ->
+            withContext(Dispatchers.Default) { i }
+        }
+
+        assertEquals(5, fixture.suspendingWithArg(5))
+    }
+
     @Test
     fun willAnswerWithControlledSuspend() = runBlocking {
         val fixture: SomeInterface = mock()

tests/src/test/kotlin/test/OngoingStubbingTest.kt

@@ -201,6 +201,36 @@ class OngoingStubbingTest : TestBase() {
         expect(result).toBe("argument-result")
     }
 
+    @Test
+    fun testOngoingStubbing_doAnswer_withDestructuredArgument() {
+        /* Given */
+        val mock = mock<Methods> {
+            on { stringResult(any()) } doAnswer { (s: String) -> "$s-result" }
+        }
+
+        /* When */
+        val result = mock.stringResult("argument")
+
+        /* Then */
+        expect(result).toBe("argument-result")
+    }
+
+    @Test
+    fun testOngoingStubbing_doAnswer_withDestructuredArguments() {
+        /* Given */
+        val mock = mock<Methods> {
+            on { varargBooleanResult(any(), any()) } doAnswer { (a: String, b: String) ->
+                a == b.trim()
+            }
+        }
+
+        /* When */
+        val result = mock.varargBooleanResult("argument", "   argument   ")
+
+        /* Then */
+        expect(result).toBe(true)
+    }
+
     @Test
     fun testMockStubbingAfterCreatingMock() {
         val mock = mock<Methods>()