DO-NOT-MERGE: test truncation fail

tests/Message.cpp

@@ -28,12 +28,22 @@ TEST_CASE("Message set creation") {
             <field type="float[3]" name="float_arr_field">description</field>
             <field type="int32_t[3]" name="int32_arr_field">description</field>
         </message>
+    <message id="77" name="COMMAND_ACK">
+      <description>Report status of a command. Includes feedback whether the command was executed. The command microservice is documented at https://mavlink.io/en/services/command.html</description>
+      <field type="uint16_t" name="command" enum="MAV_CMD">Command ID (of acknowledged command).</field>
+      <field type="uint8_t" name="result" enum="MAV_RESULT">Result of command.</field>
+      <extensions/>
+      <field type="uint8_t" name="progress" invalid="UINT8_MAX" units="%">The progress percentage when result is MAV_RESULT_IN_PROGRESS. Values: [0-100], or UINT8_MAX if the progress is unknown.</field>
+      <field type="int32_t" name="result_param2">Additional result information. Can be set with a command-specific enum containing command-specific error reasons for why the command might be denied. If used, the associated enum must be documented in the corresponding MAV_CMD (this enum should have a 0 value to indicate "unused" or "unknown").</field>
+      <field type="uint8_t" name="target_system">System ID of the target recipient. This is the ID of the system that sent the command for which this COMMAND_ACK is an acknowledgement.</field>
+      <field type="uint8_t" name="target_component">Component ID of the target recipient. This is the ID of the system that sent the command for which this COMMAND_ACK is an acknowledgement.</field>
+    </message>
     </messages>
 </mavlink>
 )"""");
 
     REQUIRE(message_set.contains("BIG_MESSAGE"));
-    REQUIRE_EQ(message_set.size(), 1);
+    REQUIRE_EQ(message_set.size(), 2);
 
     auto message = message_set.create("BIG_MESSAGE");
     CHECK_EQ(message.id(), message_set.idForMessage("BIG_MESSAGE"));
@@ -236,4 +246,34 @@ TEST_CASE("Message set creation") {
         message.set("char_arr_field", "Hello Worldo!");
         CHECK_EQ(message.get<std::string>("char_arr_field"), "Hello Worldo!");
     }
+
+    SUBCASE("Zero elision works") {
+        auto ack_message = message_set.create("COMMAND_ACK")({
+            {"command", 211},
+            {"result", 0},
+            {"progress", 0},
+            {"result_param2", 0},
+            {"target_system", 0},
+            {"target_component", 0}
+        });
+
+        int wire_size = ack_message.finalize(1, {2,3});
+        CHECK_EQ(wire_size, 13);
+
+        std::array<uint8_t, MessageDefinition::MAX_MESSAGE_SIZE> buffer{};
+        std::copy(ack_message.data(), ack_message.data() + wire_size, buffer.begin());
+
+        auto parsed_ack_message = ack_message._instantiateFromMemory(
+                ack_message.type(), ConnectionPartner{}, 11, std::move(buffer));
+
+        CHECK_EQ(parsed_ack_message.get<uint16_t>("command"), 211);
+        CHECK_EQ(parsed_ack_message.get<uint8_t>("result"), 0);
+        CHECK_EQ(parsed_ack_message.get<uint8_t>("progress"), 0);
+        CHECK_EQ(parsed_ack_message.get<int32_t>("result_param2"), 0);
+        CHECK_EQ(parsed_ack_message.get<uint8_t>("target_system"), 0);
+        CHECK_EQ(parsed_ack_message.get<uint8_t>("target_component"), 0);
+    }
+
+
+
 }