regulators: Create regulators ComparePresenceAction class

Create the ComparePresenceAction class that implements the
"compare_presence" action in the JSON config file.

Only create the .hpp file for ComparePresenceAction class first.

Signed-off-by: Bob King <Bob_King@wistron.com>
Change-Id: If2cbe5e363ae92618604887f5c534dfa10ab216f
diff --git a/phosphor-regulators/test/actions/compare_presence_action_tests.cpp b/phosphor-regulators/test/actions/compare_presence_action_tests.cpp
new file mode 100644
index 0000000..e290a0f
--- /dev/null
+++ b/phosphor-regulators/test/actions/compare_presence_action_tests.cpp
@@ -0,0 +1,61 @@
+/**
+ * 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 "action_environment.hpp"
+#include "compare_presence_action.hpp"
+#include "id_map.hpp"
+#include "mock_action.hpp"
+
+#include <exception>
+#include <memory>
+#include <stdexcept>
+#include <utility>
+
+#include <gtest/gtest.h>
+
+using namespace phosphor::power::regulators;
+
+TEST(ComparePresenceActionTests, Constructor)
+{
+    ComparePresenceAction action{"/system/chassis/motherboard/cpu3", true};
+    EXPECT_EQ(action.getFRU(), "/system/chassis/motherboard/cpu3");
+    EXPECT_EQ(action.getValue(), true);
+}
+
+TEST(ComparePresenceActionTests, Execute)
+{
+    // TODO: Not implemented yet
+}
+
+TEST(ComparePresenceActionTests, GetFRU)
+{
+    ComparePresenceAction action{"/system/chassis/motherboard/cpu2", true};
+    EXPECT_EQ(action.getFRU(), "/system/chassis/motherboard/cpu2");
+}
+
+TEST(ComparePresenceActionTests, GetValue)
+{
+    ComparePresenceAction action{"/system/chassis/motherboard/cpu3", false};
+    EXPECT_EQ(action.getValue(), false);
+}
+
+TEST(ComparePresenceActionTests, ToString)
+{
+    ComparePresenceAction action{"/system/chassis/motherboard/cpu2", true};
+    EXPECT_EQ(action.toString(),
+              "compare_presence: { fru: /system/chassis/motherboard/cpu2, "
+              "value: true }");
+}