Improved query error handling.

src/morethantext/mod.rs

@@ -9,15 +9,17 @@ const ENTRY: &str = "EntryPoint";
 
 #[derive(Debug)]
 enum ErrorCode {
+    // General
     Undefined(String),
-    IncorrectDataType(String),
+    // Cache Entry
+    EntryNotFound(String),
 }
 
 impl fmt::Display for ErrorCode {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
             ErrorCode::Undefined(msg) => write!(f, "{}", msg),
-            ErrorCode::IncorrectDataType(item) => write!(f, "data type '{}' does not exist", item),
+            ErrorCode::EntryNotFound(id) => write!(f, "entry '{}' was not found", id),
         }
     }
 }
@@ -36,13 +38,10 @@ mod errorcodes {
     }
 
     #[test]
-    fn incorrect_data_type() {
+    fn bad_entry() {
         for item in ITEMS {
-            let err = ErrorCode::IncorrectDataType(item.to_string());
-            assert_eq!(
-                err.to_string(),
-                format!("data type '{}' does not exist", item)
-            );
+            let err = ErrorCode::EntryNotFound(item.to_string());
+            assert_eq!(err.to_string(), format!("entry '{}' was not found", item));
         }
     }
 }
@@ -107,12 +106,12 @@ mod errors {
     }
 
     #[test]
-    fn create_from_different_code() {
-        let code = ErrorCode::IncorrectDataType("nuts".to_string());
+    fn create_missing_entry() {
+        let code = ErrorCode::EntryNotFound("an_id".to_string());
         let err = MTTError::from_code(code);
         match err.code {
-            ErrorCode::IncorrectDataType(_) => (),
-            _ => assert!(false, "{:?} is not incorrect data type", err.code),
+            ErrorCode::EntryNotFound(_) => (),
+            _ => assert!(false, "{:?} is not undefined", err.code),
         }
     }
 }
@@ -274,7 +273,9 @@ impl Cache {
             if id == ENTRY {
                 output.insert(ENTRY.to_string(), DataType::new("store"));
             } else {
-                return Err(MTTError::new("fred"));
+                return Err(MTTError::from_code(ErrorCode::EntryNotFound(
+                    id.to_string(),
+                )));
             }
         }
         Ok(output)
@@ -287,17 +288,13 @@ impl Cache {
     async fn start(&self, listener: Receiver<ToCache>) {
         loop {
             match listener.recv().await.unwrap() {
-                ToCache::Query(qry) => {
-                    match self.query(&qry.ids).await {
-                        Ok(data) => qry.reply.send(FromCache::Data(data)).await.unwrap(),
-                        Err(error) => qry.reply.send(FromCache::Error(error)).await.unwrap(),
-                    }
+                ToCache::Query(qry) => match self.query(&qry.ids).await {
+                    Ok(data) => qry.reply.send(FromCache::Data(data)).await.unwrap(),
+                    Err(error) => qry.reply.send(FromCache::Error(error)).await.unwrap(),
                 },
-                ToCache::Commit(commit) => {
-                    match self.commit().await {
-                        Ok(_) => commit.reply.send(FromCache::Ok).await.unwrap(),
-                        Err(error) => commit.reply.send(FromCache::Error(error)).await.unwrap(),
-                    }
+                ToCache::Commit(commit) => match self.commit().await {
+                    Ok(_) => commit.reply.send(FromCache::Ok).await.unwrap(),
+                    Err(error) => commit.reply.send(FromCache::Error(error)).await.unwrap(),
                 },
             }
         }
@@ -376,9 +373,29 @@ mod caches {
     }
 
     #[async_std::test]
-    async fn add_database_commit() {
-        //let dir = tempdir().unwrap();
-        //let s_cache = start_cache(dir.path()).await;
+    async fn get_store() {
+        let dir = tempdir().unwrap();
+        let cache = Cache::new(dir.path()).await.unwrap();
+        let output = cache.query(&[ENTRY.to_string()].to_vec()).await.unwrap();
+        let result = output.get(ENTRY).unwrap();
+        match result {
+            DataType::DBMap(_) => (),
+            _ => assert!(false, "{:?} should have been an Ok.", result),
+        }
+    }
+
+    #[async_std::test]
+    async fn bad_get() {
+        let dir = tempdir().unwrap();
+        let cache = Cache::new(dir.path()).await.unwrap();
+        let bad_id = "really_bad_id";
+        match cache.query(&[bad_id.to_string()].to_vec()).await {
+            Ok(_) => assert!(false, "Should have produced an error."),
+            Err(err) => match err.code {
+                ErrorCode::EntryNotFound(id) => assert_eq!(id, bad_id),
+                _ => assert!(false, "{:?} should have been EntryNotFound.", err.code),
+            },
+        }
     }
 }