Got backend using errors.

src/document.rs

@@ -31,11 +31,18 @@ impl Document {
     fn listen(&mut self) {
         loop {
             let msg = self.rx.recv().unwrap();
-            let mut reply = msg.reply(MsgType::Document);
-            if msg.get_data("name").is_some() {
-                reply = msg.reply(MsgType::Error);
-                reply.add_data("error_type", ErrorType::DocumentNotFound);
-            }
+            let mut reply = match msg.get_data("name") {
+                Some(name) => {
+                    if name.to_string() == "root" {
+                        msg.reply(MsgType::Document)
+                    } else {
+                        let mut output = msg.reply(MsgType::Error);
+                        output.add_data("error_type", ErrorType::DocumentNotFound);
+                        output
+                    }
+                },
+                None => msg.reply(MsgType::Document),
+            };
             reply.add_data("doc", "Something goes hwew");
             self.queue.send(reply).unwrap();
         }
@@ -95,4 +102,18 @@ pub mod documents {
             None => unreachable!("should contain error type"),
         }
     }
+
+    #[test]
+    fn root_always_exists() {
+        let (queue, rx) = setup_document();
+        let name = format!("name-{}", Uuid::new_v4());
+        let mut msg = Message::new(MsgType::DocumentRequest);
+        msg.add_data("name", "root");
+        queue.send(msg);
+        let reply = rx.recv().unwrap();
+        match reply.get_msg_type() {
+            MsgType::Document => {},
+            _ => unreachable!("Got '{:?}': should have been a document", reply.get_msg_type()),
+        }
+    }
 }