Create regulators SetDeviceAction class

Create the SetDeviceAction class that implements the set_device action
in the JSON config file.

Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: I31b8fbc144aa2cb2b4b3373fda559b0404d271cb
diff --git a/phosphor-regulators/src/actions/set_device_action.hpp b/phosphor-regulators/src/actions/set_device_action.hpp
new file mode 100644
index 0000000..3c61208
--- /dev/null
+++ b/phosphor-regulators/src/actions/set_device_action.hpp
@@ -0,0 +1,91 @@
+/**
+ * Copyright © 2019 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.
+ */
+#pragma once
+
+#include "action.hpp"
+#include "action_environment.hpp"
+
+#include <string>
+
+namespace phosphor
+{
+namespace power
+{
+namespace regulators
+{
+
+/**
+ * @class SetDeviceAction
+ *
+ * Sets the device that will be used by subsequent actions.
+ *
+ * Implements the set_device action in the JSON config file.
+ */
+class SetDeviceAction : public Action
+{
+  public:
+    // Specify which compiler-generated methods we want
+    SetDeviceAction() = delete;
+    SetDeviceAction(const SetDeviceAction&) = delete;
+    SetDeviceAction(SetDeviceAction&&) = delete;
+    SetDeviceAction& operator=(const SetDeviceAction&) = delete;
+    SetDeviceAction& operator=(SetDeviceAction&&) = delete;
+    virtual ~SetDeviceAction() = default;
+
+    /**
+     * Constructor.
+     *
+     * @param deviceID device ID
+     */
+    explicit SetDeviceAction(const std::string& deviceID) : deviceID{deviceID}
+    {
+    }
+
+    /**
+     * Executes this action.
+     *
+     * Sets the current device ID in the ActionEnvironment.  This causes
+     * subsequent actions to use that device.
+     *
+     * @param environment Action execution environment.
+     * @return true
+     */
+    virtual bool execute(ActionEnvironment& environment) override
+    {
+        environment.setDeviceID(deviceID);
+        return true;
+    }
+
+    /**
+     * Returns the device ID.
+     *
+     * @return device ID
+     */
+    const std::string& getDeviceID() const
+    {
+        return deviceID;
+    }
+
+  private:
+    /**
+     * Device ID.
+     */
+    const std::string deviceID{};
+};
+
+} // namespace regulators
+} // namespace power
+} // namespace phosphor
diff --git a/phosphor-regulators/test/actions/meson.build b/phosphor-regulators/test/actions/meson.build
index 8c3d2b8..d6821de 100644
--- a/phosphor-regulators/test/actions/meson.build
+++ b/phosphor-regulators/test/actions/meson.build
@@ -1,6 +1,7 @@
 test('phosphor-regulators-actions-tests',
      executable('phosphor-regulators-actions-tests',
                 'action_environment_tests.cpp',
+                'set_device_action_tests.cpp',
                 dependencies: [
                     gmock,
                     gtest,
diff --git a/phosphor-regulators/test/actions/set_device_action_tests.cpp b/phosphor-regulators/test/actions/set_device_action_tests.cpp
new file mode 100644
index 0000000..6164a46
--- /dev/null
+++ b/phosphor-regulators/test/actions/set_device_action_tests.cpp
@@ -0,0 +1,65 @@
+/**
+ * Copyright © 2019 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_environment.hpp"
+#include "device.hpp"
+#include "id_map.hpp"
+#include "set_device_action.hpp"
+
+#include <exception>
+
+#include <gtest/gtest.h>
+
+using namespace phosphor::power::regulators;
+
+TEST(SetDeviceActionTests, Constructor)
+{
+    SetDeviceAction action{"regulator1"};
+    EXPECT_EQ(action.getDeviceID(), "regulator1");
+}
+
+TEST(SetDeviceActionTests, Execute)
+{
+    // Create IDMap
+    IDMap idMap{};
+    Device reg1{"regulator1"};
+    idMap.addDevice(reg1);
+    Device reg2{"regulator2"};
+    idMap.addDevice(reg2);
+
+    // Create ActionEnvironment
+    ActionEnvironment env{idMap, "regulator1"};
+
+    // Create action
+    SetDeviceAction action{"regulator2"};
+
+    // Execute action
+    try
+    {
+        EXPECT_EQ(env.getDeviceID(), "regulator1");
+        EXPECT_EQ(action.execute(env), true);
+        EXPECT_EQ(env.getDeviceID(), "regulator2");
+    }
+    catch (const std::exception& error)
+    {
+        ADD_FAILURE() << "Should not have caught exception.";
+    }
+}
+
+TEST(SetDeviceActionTests, GetDeviceID)
+{
+    SetDeviceAction action{"io_expander_0"};
+    EXPECT_EQ(action.getDeviceID(), "io_expander_0");
+}