Continued work to get items into a session.

src/morethantext/databases.rs

@@ -105,6 +105,10 @@ impl SessionData for Databases {
             Ok(_) => (),
             Err(err) => return Err(err),
         }
+        match self.db_map.get(value) {
+            Some(_) => return Err(DBError::new(format!("database {} already exists", value))),
+            None => (),
+        }
         self.db_map.insert(value.to_string(), data.to_string());
         let mut output = Vec::new();
         output.push(data.to_string());
@@ -117,8 +121,10 @@ impl SessionData for Databases {
             Err(err) => return Err(err),
         }
         let mut output = Vec::new();
-        let data = self.db_map.get(value).unwrap();
+        match self.db_map.get(value) {
-        output.push(data.to_string());
+            Some(data) => output.push(data.to_string()),
+            None => (),
+        }
         Ok(output)
     }
 
@@ -307,4 +313,25 @@ mod session_data {
             Err(_) => (),
         }
     }
+
+    #[test]
+    fn unique_names() {
+        let mut dbs = Databases::new();
+        let value = "wilma";
+        dbs.add("name", value, "something").unwrap();
+        match dbs.add("name", value, "overwrite") {
+            Ok(_) => assert!(false, "Duplicate names should produce an error."),
+            Err(err) => assert_eq!(
+                err.to_string(),
+                format!("database {} already exists", value)
+            ),
+        }
+    }
+
+    #[test]
+    fn get_missing() {
+        let dbs = Databases::new();
+        let output = dbs.get("name", "melvin").unwrap();
+        assert_eq!(output, Vec::<String>::new());
+    }
 }