tests/unittests: add unit tests for core_mbox

tests/unittests/tests-core/Makefile.include

@@ -0,0 +1 @@
+USEMODULE += core_mbox

tests/unittests/tests-core/tests-core-mbox.c

@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2022 Otto-von-Guericke-Universität Magdeburg
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+#include <limits.h>
+
+#include "embUnit.h"
+
+#include "mbox.h"
+
+#include "tests-core.h"
+
+#define QUEUE_SIZE  8
+
+static unsigned gen_val(unsigned i) {
+    return i + 1337;
+}
+
+static void test_mbox_put_get(void)
+{
+    mbox_t mbox;
+    msg_t queue[QUEUE_SIZE];
+    msg_t msg = { .type = 0 };
+    mbox_init(&mbox, queue, ARRAY_SIZE(queue));
+    TEST_ASSERT_EQUAL_INT(0, mbox_avail(&mbox));
+
+    /* Filling the queue up to capacity one item at a time. This should
+     * succeed every single time. */
+    for (unsigned i = 0; i < ARRAY_SIZE(queue); i++) {
+        msg.type = i;
+        msg.content.value = gen_val(i);
+        TEST_ASSERT_EQUAL_INT(1, mbox_try_put(&mbox, &msg));
+    }
+
+    /* Adding one item over capacity must fail. */
+    msg.type = 4242;
+    msg.content.value = 4242;
+    TEST_ASSERT_EQUAL_INT(0, mbox_try_put(&mbox, &msg));
+
+    /* The queue must contain the items we filled in and in that order. */
+    for (unsigned i = 0; i < ARRAY_SIZE(queue); i++) {
+        TEST_ASSERT_EQUAL_INT(i, queue[i].type);
+        TEST_ASSERT_EQUAL_INT(gen_val(i), queue[i].content.value);
+    }
+
+    /* Now we drain the queue one item at a time. We expect to get the exact
+     * items we filled in and in that order. */
+    for (unsigned i = 0; i < ARRAY_SIZE(queue); i++) {
+        TEST_ASSERT_EQUAL_INT(1, mbox_try_get(&mbox, &msg));
+        TEST_ASSERT_EQUAL_INT(i, msg.type);
+        TEST_ASSERT_EQUAL_INT(gen_val(i), msg.content.value);
+    }
+
+    /* The queue is now empty. Getting one more item (non-blocking) must fail */
+    TEST_ASSERT_EQUAL_INT(0, mbox_try_get(&mbox, &msg));
+}
+
+Test *tests_core_mbox_tests(void)
+{
+    EMB_UNIT_TESTFIXTURES(fixtures) {
+        new_TestFixture(test_mbox_put_get),
+    };
+
+    EMB_UNIT_TESTCALLER(core_mbox_tests, NULL, NULL, fixtures);
+
+    return (Test *)&core_mbox_tests;
+}

tests/unittests/tests-core/tests-core.c

@@ -15,6 +15,7 @@ void tests_core(void)
     TESTS_RUN(tests_core_cib_tests());
     TESTS_RUN(tests_core_clist_tests());
     TESTS_RUN(tests_core_list_tests());
+    TESTS_RUN(tests_core_mbox_tests());
     TESTS_RUN(tests_core_priority_queue_tests());
     TESTS_RUN(tests_core_byteorder_tests());
     TESTS_RUN(tests_core_ringbuffer_tests());

tests/unittests/tests-core/tests-core.h

@@ -64,6 +64,13 @@ Test *tests_core_clist_tests(void);
  */
 Test *tests_core_list_tests(void);
 
+/**
+ * @brief   Generates tests for mbox.h
+ *
+ * @return  embUnit tests if successful, NULL if not.
+ */
+Test *tests_core_mbox_tests(void);
+
 /**
  * @brief   Generates tests for priority_queue.h
  *