Got backend using errors.

src/lib.rs

@@ -13,11 +13,94 @@ use queue::{Message, MsgType, Queue};
 use session::Session;
 use uuid::Uuid;
 
+pub enum ActionType {
+    Get,
+    Add,
+    Update,
+}
+
 #[derive(Clone, Debug)]
 pub enum ErrorType {
     DocumentNotFound,
 }
 
+pub struct MTTReply {
+    document: String,
+    error_type: Option<ErrorType>,
+}
+
+impl MTTReply {
+    fn new(msg: Message) -> Self {
+        Self {
+            document: match msg.get_data("doc") {
+                Some(doc) => doc.to_string(),
+                None => "".to_string(),
+            },
+            error_type: match msg.get_data("error_type") {
+                Some(err) => Some(err.to_error_type().unwrap()),
+                None => None,
+            },
+        }
+    }
+
+    pub fn get_document(&self) -> String {
+        self.document.clone()
+    }
+
+    pub fn get_error(&self) -> Option<ErrorType> {
+        self.error_type.clone()
+    }
+}
+
+#[cfg(test)]
+mod mtt_replies {
+    use super::*;
+
+    #[test]
+    fn create_reply_with_no_error() {
+        let mut msg = Message::new(MsgType::Document);
+        let content = format!("content-{}", Uuid::new_v4());
+        msg.add_data("doc", content.to_string());
+        let reply = MTTReply::new(msg);
+        assert!(reply.get_error().is_none());
+        assert_eq!(reply.get_document(), content);
+    }
+
+    #[test]
+    fn create_reply_with_error() {
+        let mut msg = Message::new(MsgType::Error);
+        msg.add_data("error_type", ErrorType::DocumentNotFound);
+        let reply = MTTReply::new(msg);
+        match reply.get_error() {
+            Some(err) => match err {
+                ErrorType::DocumentNotFound => {},
+            },
+            None => unreachable!("should return an error type"),
+        }
+        assert_eq!(reply.get_document(), "");
+    }
+
+    #[test]
+    fn no_error() {
+        let msg = Message::new(MsgType::Document);
+        let reply = MTTReply::new(msg);
+        assert!(reply.get_error().is_none());
+    }
+
+    #[test]
+    fn some_error() {
+        let mut msg = Message::new(MsgType::Error);
+        msg.add_data("error_type", ErrorType::DocumentNotFound);
+        let reply = MTTReply::new(msg);
+        match reply.get_error() {
+            Some(err) => match err {
+                ErrorType::DocumentNotFound => {},
+            },
+            None => unreachable!("should return an error type"),
+        }
+    }
+}
+
 #[derive(Clone)]
 pub struct MoreThanText {
     client_channel: ClientChannel,
@@ -48,11 +131,55 @@ impl MoreThanText {
         reply.get_data("sess_id").unwrap().to_uuid().unwrap()
     }
 
-    pub fn get_document(&self, sess_id: Uuid) -> String {
+    pub fn get_document<S>(&self, sess_id: Uuid, action: ActionType, doc_name: S) -> MTTReply where S: Into<String> {
         let mut msg = Message::new(MsgType::DocumentRequest);
         msg.add_data("sess_id", sess_id);
+        msg.add_data("name", doc_name.into());
         let rx = self.client_channel.send(msg);
         let reply = rx.recv().unwrap();
-        reply.get_data("doc").unwrap().to_string()
+        MTTReply::new(reply)
+    }
+}
+
+#[cfg(test)]
+mod mtt {
+    use super::*;
+
+    #[test]
+    fn session_id_is_unique() {
+        let mut mtt = MoreThanText::new();
+        let input: Option<String> = None;
+        let mut ids: Vec<Uuid> = Vec::new();
+        for _ in 0..10 {
+            let id = mtt.validate_session(input.clone());
+            assert!(!ids.contains(&id));
+            ids.push(id);
+        }
+    }
+
+    #[test]
+    fn reuse_existing_session() {
+        let mut mtt = MoreThanText::new();
+        let initial: Option<String> = None;
+        let id = mtt.validate_session(initial);
+        let output = mtt.validate_session(Some(id.clone()));
+        assert_eq!(output, id);
+    }
+
+    #[test]
+    fn get_root_document_with_str() {
+        let mut mtt = MoreThanText::new();
+        let id = mtt.validate_session(Some(Uuid::new_v4()));
+        let output = mtt.get_document(id, ActionType::Get, "root");
+        assert!(output.get_error().is_none());
+    }
+
+    #[test]
+    fn get_root_document_with_string() {
+        let mut mtt = MoreThanText::new();
+        let id = mtt.validate_session(Some(Uuid::new_v4()));
+        let output = mtt.get_document(id, ActionType::Get, "root".to_string());
+        assert!(output.get_error().is_none());
+
     }
 }