regulators: Create PresenceDetection class

Create C++ class that implements the 'presence_detection' element from
the JSON config file.  See presence_detection.md for more information.

The execute() method of this class will be implemented in a future
commit.

Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: Id6e1d66afe9179c92455d3f7b8f15bb54745f3eb
diff --git a/phosphor-regulators/test/presence_detection_tests.cpp b/phosphor-regulators/test/presence_detection_tests.cpp
new file mode 100644
index 0000000..7f3c10f
--- /dev/null
+++ b/phosphor-regulators/test/presence_detection_tests.cpp
@@ -0,0 +1,56 @@
+/**
+ * Copyright © 2020 IBM Corporation
+ *
+ * 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.
+ */
+#include "action.hpp"
+#include "mock_action.hpp"
+#include "presence_detection.hpp"
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include <gtest/gtest.h>
+
+using namespace phosphor::power::regulators;
+
+TEST(PresenceDetectionTests, Constructor)
+{
+    std::vector<std::unique_ptr<Action>> actions{};
+    actions.push_back(std::make_unique<MockAction>());
+
+    PresenceDetection presenceDetection(std::move(actions));
+    EXPECT_EQ(presenceDetection.getActions().size(), 1);
+}
+
+TEST(PresenceDetectionTests, Execute)
+{
+    // TODO: Implement test when execute() function is done
+}
+
+TEST(PresenceDetectionTests, GetActions)
+{
+    std::vector<std::unique_ptr<Action>> actions{};
+
+    MockAction* action1 = new MockAction{};
+    actions.push_back(std::unique_ptr<MockAction>{action1});
+
+    MockAction* action2 = new MockAction{};
+    actions.push_back(std::unique_ptr<MockAction>{action2});
+
+    PresenceDetection presenceDetection(std::move(actions));
+    EXPECT_EQ(presenceDetection.getActions().size(), 2);
+    EXPECT_EQ(presenceDetection.getActions()[0].get(), action1);
+    EXPECT_EQ(presenceDetection.getActions()[1].get(), action2);
+}