1 files changed, 70 insertions, 0 deletions
diff --git a/tests/utils/testutils/java/test/util/MockitoUtils.kt b/tests/utils/testutils/java/test/util/MockitoUtils.kt
new file mode 100644
index 000000000000..5151abe54108
--- /dev/null
+++ b/tests/utils/testutils/java/test/util/MockitoUtils.kt
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package test.util
+
+import org.mockito.Answers
+import org.mockito.Mockito
+import org.mockito.invocation.InvocationOnMock
+import org.mockito.stubbing.Answer
+import org.mockito.stubbing.Stubber
+
+object MockitoUtils {
+    val ANSWER_THROWS = Answer<Any?> {
+        when (val name = it.method.name) {
+            "toString" -> return@Answer Answers.CALLS_REAL_METHODS.answer(it)
+            else -> {
+                val arguments = it.arguments
+                        ?.takeUnless { it.isEmpty() }
+                        ?.joinToString()
+                        ?.let {
+                            "with $it"
+                        }
+                        .orEmpty()
+
+                throw UnsupportedOperationException("${it.mock::class.java.simpleName}#$name " +
+                        "$arguments should not be called")
+            }
+        }
+    }
+}
+
+inline fun <reified T> mock(block: T.() -> Unit = {}) = Mockito.mock(T::class.java).apply(block)
+
+fun <Type> Stubber.whenever(mock: Type) = Mockito.`when`(mock)
+fun <Type : Any?> whenever(mock: Type) = Mockito.`when`(mock)
+
+@Suppress("UNCHECKED_CAST")
+fun <Type : Any?> whenever(mock: Type, block: InvocationOnMock.() -> Any?) =
+        Mockito.`when`(mock).thenAnswer { block(it) }
+
+fun whenever(mock: Unit) = Mockito.`when`(mock).thenAnswer { }
+
+inline fun <reified T> mockThrowOnUnmocked(block: T.() -> Unit): T {
+    val swappingAnswer = object : Answer<Any?> {
+        var delegate: Answer<*> = Answers.RETURNS_DEFAULTS
+
+        override fun answer(invocation: InvocationOnMock?): Any? {
+            return delegate.answer(invocation)
+        }
+    }
+
+    return Mockito.mock(T::class.java, swappingAnswer).apply(block)
+            .also {
+                // To allow when() usage inside block, only swap to throwing afterwards
+                swappingAnswer.delegate = MockitoUtils.ANSWER_THROWS
+            }
+}