GTest functional tests that include parameters and uORB messaging (#12521)

* Add kdevelop to gitignore

* Add test stubs

* Rename px4_add_gtest to px4_add_unit_gtest

* Add infrastructure to run functional tests

* Add example tests with parameters and uorb messages

* Fix memory issues in destructors in uORB manager and CDev

* Add a more real-world test of the collision prevention

src/lib/parameters/ParameterTest.cpp

@@ -0,0 +1,114 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2019 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#include <px4_module_params.h>
+#include <uORB/Subscription.hpp>
+#include <uORB/topics/obstacle_distance.h>
+#include <uORB/uORBManager.hpp>
+
+#include <gtest/gtest.h>
+
+class ParameterTest : public ::testing::Test
+{
+public:
+	void SetUp() override
+	{
+		uORB::Manager::initialize();
+		param_init();
+	}
+
+	void TearDown() override
+	{
+		param_reset_all();
+		uORB::Manager::terminate();
+	}
+};
+
+
+TEST_F(ParameterTest, testParamReadWrite)
+{
+	// GIVEN a parameter handle
+	param_t param = param_handle(px4::params::MPC_COL_PREV_D);
+
+	// WHEN: we get the parameter
+	float value = -999.f;
+	int status = param_get(param, &value);
+
+	// THEN it should be successful and have the default value
+	EXPECT_EQ(0, status);
+	EXPECT_EQ(-1, value);
+
+	// WHEN: we set the parameter
+	value = 42.f;
+	status = param_set(param, &value);
+
+	// THEN: it should be successful
+	EXPECT_EQ(0, status);
+
+	// WHEN: we get the parameter again
+	float value2 = -1999.f;
+	status = param_get(param, &value2);
+
+	// THEN: it should be exactly the value we set
+	EXPECT_EQ(0, status);
+	EXPECT_EQ(42.f, value2);
+}
+
+
+TEST_F(ParameterTest, testUorbSendReceive)
+{
+	// GIVEN: a uOrb message
+	obstacle_distance_s message;
+	memset(&message, 0xDEAD, sizeof(message));
+	message.min_distance = 1.f;
+	message.max_distance = 10.f;
+
+	// AND: a subscriber
+	uORB::SubscriptionData<obstacle_distance_s> sub_obstacle_distance{ORB_ID(obstacle_distance)};
+
+	// WHEN we send the message
+	orb_advert_t obstacle_distance_pub = orb_advertise(ORB_ID(obstacle_distance), &message);
+	ASSERT_TRUE(obstacle_distance_pub != nullptr);
+
+	// THEN: the subscriber should receive the message
+	sub_obstacle_distance.update();
+	const obstacle_distance_s &obstacle_distance = sub_obstacle_distance.get();
+
+	// AND: the values we got should be the same
+	EXPECT_EQ(message.timestamp, obstacle_distance.timestamp);
+	EXPECT_EQ(message.min_distance, obstacle_distance.min_distance);
+	EXPECT_EQ(message.max_distance, obstacle_distance.max_distance);
+
+	// AND: all the bytes should be equal
+	EXPECT_EQ(0, memcmp(&message, &obstacle_distance, sizeof(message)));
+}