Add a Message constructor that takes a SimpleMessage

include/loot/metadata/message.h

@@ -76,6 +76,14 @@ public:
                    const std::vector<MessageContent>& content,
                    const std::string& condition = "");
 
+  /**
+   * Construct a Message object from a SimpleMessage object.
+   * @param  message
+   *         The SimpleMessage object.
+   * @return A Message object.
+   */
+  LOOT_API explicit Message(const SimpleMessage& message);
+
   /**
    * A less-than operator implemented with no semantics so that Message objects
    * can be stored in sets.

src/api/metadata/message.cpp

@@ -34,10 +34,9 @@ Message::Message() : type_(MessageType::say) {}
 Message::Message(const MessageType type,
                  const std::string& content,
                  const std::string& condition) :
-    type_(type),
-    ConditionalMetadata(condition) {
-  content_.push_back(MessageContent(content));
-}
+    type_(type), 
+    content_({MessageContent(content)}),
+    ConditionalMetadata(condition) {}
 
 Message::Message(const MessageType type,
                  const std::vector<MessageContent>& content,
@@ -58,6 +57,11 @@ Message::Message(const MessageType type,
   }
 }
 
+Message::Message(const SimpleMessage& message) :
+    type_(message.type),
+    content_({MessageContent(message.text, message.language)}),
+    ConditionalMetadata(message.condition) {}
+
 bool Message::operator<(const Message& rhs) const {
   if (type_ < rhs.type_) {
     return true;

src/tests/api/internals/metadata/message_test.h

@@ -82,6 +82,22 @@ TEST_P(
                std::invalid_argument);
 }
 
+TEST_P(MessageTest,
+  simpleMessageConstructorShouldCreateAMessageWithASingleContentString) {
+  SimpleMessage simple;
+  simple.type = MessageType::error;
+  simple.text = "ERROR";
+  simple.language = "fr";
+  simple.condition = "condition";
+
+  Message message(simple);
+
+  EXPECT_EQ(MessageType::error, message.GetType());
+  EXPECT_EQ(MessageContents({MessageContent(simple.text, simple.language)}),
+            message.GetContent());
+  EXPECT_EQ("condition", message.GetCondition());
+}
+
 TEST_P(MessageTest, equalityShouldRequireEqualMessageTypes) {
   Message message1(MessageType::say, "content");
   Message message2(MessageType::say, "content");