feat: Add testkit for testing behavior

This change adds a testkit for synchronously testking Behavior
implementations.

1 files changed, 90 insertions, 0 deletions

diff --git a/odcsim-testkit/src/main/kotlin/com/atlarge/odcsim/testkit/TestInbox.kt b/odcsim-testkit/src/main/kotlin/com/atlarge/odcsim/testkit/TestInbox.kt
new file mode 100644
index 00000000..de240143
--- /dev/null
+++ b/odcsim-testkit/src/main/kotlin/com/atlarge/odcsim/testkit/TestInbox.kt
@@ -0,0 +1,90 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * 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 com.atlarge.odcsim.testkit
+
+import com.atlarge.odcsim.ActorRef
+import com.atlarge.odcsim.Envelope
+
+/**
+ * A helper class for testing messages sent to an [ActorRef].
+ *
+ * @param T The shape of the messages the inbox accepts.
+ */
+interface TestInbox<T : Any> {
+    /**
+     * The actor reference of this inbox.
+     */
+    val ref: ActorRef<T>
+
+    /**
+     * A flag to indicate whether the inbox contains any messages.
+     */
+    val hasMessages: Boolean
+
+    /**
+     * Receive the oldest message from the inbox and remove it.
+     *
+     * @return The message that has been received.
+     * @throws NoSuchElementException if the inbox is empty.
+     */
+    fun receiveMessage(): T = receiveEnvelope().message
+
+    /**
+     * Receive the oldest message from the inbox and remove it.
+     *
+     * @return The envelope containing the message that has been received.
+     * @throws NoSuchElementException if the inbox is empty.
+     */
+    fun receiveEnvelope(): Envelope<T>
+
+    /**
+     * Receive all messages from the inbox and empty it.
+     *
+     * @return The list of messages in the inbox.
+     */
+    fun receiveAll(): List<Envelope<T>>
+
+    /**
+     * Clear all messages from the inbox.
+     */
+    fun clear()
+
+    /**
+     * Assert that the oldest message is equal to the [expected] message and remove
+     * it from the inbox.
+     *
+     * @param expected The expected message to be the oldest in the inbox.
+     */
+    fun expectMessage(expected: T)
+
+    /**
+     * Assert that the oldest message is equal to the [expected] message and remove
+     * it from the inbox.
+     *
+     * @param expected The expected message to be the oldest in the inbox.
+     * @param message The failure message to fail with.
+     */
+    fun expectMessage(expected: T, message: String)
+}