added id to name mapping module

src/id_mapping.rs

@@ -0,0 +1,76 @@
+use crate::tally_id::TallyID;
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+
+#[derive(Deserialize, Serialize, Debug, PartialEq, Eq, Clone)]
+pub struct Name {
+    pub first: String,
+    pub last: String,
+}
+
+#[derive(Deserialize, Serialize, Clone)]
+pub struct IDMapping {
+    id_map: HashMap<TallyID, Name>,
+}
+
+impl IDMapping {
+    pub fn new() -> Self {
+        IDMapping {
+            id_map: HashMap::new(),
+        }
+    }
+
+    pub fn map(&self, id: &TallyID) -> Option<&Name> {
+        self.id_map.get(id)
+    }
+
+    pub fn add_mapping(&mut self, id: TallyID, name: Name) {
+        self.id_map.insert(id, name);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn basic() {
+        let mut map = IDMapping::new();
+        let id1 = TallyID("A2Fb44".to_owned());
+        let name1 = Name {
+            first: "Max".to_owned(),
+            last: "Mustermann".to_owned(),
+        };
+
+        map.add_mapping(id1.clone(), name1.clone());
+
+        let res = map.map(&id1);
+
+        assert_eq!(res, Some(&name1));
+    }
+
+    #[test]
+    fn multiple() {
+        let mut map = IDMapping::new();
+        let id1 = TallyID("A2Fb44".to_owned());
+        let name1 = Name {
+            first: "Max".to_owned(),
+            last: "Mustermann".to_owned(),
+        };
+
+        let id2 = TallyID("7D3DF5B5".to_owned());
+        let name2 = Name {
+            first: "First".to_owned(),
+            last: "Last".to_owned(),
+        };
+
+        map.add_mapping(id1.clone(), name1.clone());
+        map.add_mapping(id2.clone(), name2.clone());
+
+        let res = map.map(&id1);
+        assert_eq!(res, Some(&name1));
+
+        let res = map.map(&id2);
+        assert_eq!(res, Some(&name2));
+    }
+}