Added databases structure.

src/morethantext/databases.rs

@@ -0,0 +1,81 @@
+use std::collections::HashMap;
+
+#[derive(Clone)]
+pub struct Databases {
+    db_map: HashMap<String, String>,
+}
+
+impl Databases {
+    pub fn new() -> Self {
+        Self {
+            db_map: HashMap::new(),
+        }
+    }
+
+    fn add_database(&mut self, name: &str, id: &str) -> Option<String> {
+        if self.db_map.contains_key(name) {
+            None
+        } else {
+            self.db_map.insert(name.to_string(), id.to_string());
+            Some(id.to_string())
+        }
+    }
+
+    fn get_database(&self, name: &str) -> Option<String> {
+        self.db_map.get(name).cloned()
+    }
+
+    fn show(&self) -> Vec<String> {
+        let mut names: Vec<String> = self.db_map.clone().into_keys().collect();
+        names.sort();
+        names
+    }
+}
+
+#[cfg(test)]
+mod functions {
+    use super::*;
+
+    #[test]
+    fn add_entry() {
+        let name = "fred";
+        let id = "123456";
+        let mut dbs = Databases::new();
+        let output = dbs.add_database(name, id);
+        assert_eq!(output, Some(id.to_string()));
+        let output = dbs.get_database(name);
+        assert_eq!(output, Some(id.to_string()));
+    }
+
+    #[test]
+    fn entry_cannot_be_over_written() {
+        let name = "barney";
+        let id = "abcde";
+        let mut dbs = Databases::new();
+        dbs.add_database(name, id);
+        let output = dbs.add_database(name, "09876");
+        assert_eq!(output, None);
+        let output = dbs.get_database(name);
+        assert_eq!(output, Some(id.to_string()));
+    }
+
+    #[test]
+    fn get_bad_database() {
+        let dbs = Databases::new();
+        let output = dbs.get_database("missing");
+        assert_eq!(output, None);
+    }
+
+    #[test]
+    fn list_databases() {
+        let mut dbs = Databases::new();
+        dbs.add_database("zebra", "a");
+        dbs.add_database("alpha", "a");
+        dbs.add_database("charlie", "a");
+        dbs.add_database("wilma", "a");
+        dbs.add_database("frank", "a");
+        let expected = ["alpha", "charlie", "frank", "wilma", "zebra"];
+        let output = dbs.show();
+        assert_eq!(output, expected);
+    }
+}

src/morethantext/mod.rs

@@ -1,3 +1,4 @@
+mod databases;
 pub mod error;
 
 use async_std::{
@@ -6,6 +7,7 @@ use async_std::{
     sync::{Arc, Mutex},
     task::{sleep, spawn},
 };
+use databases::Databases;
 use error::DBError;
 use rand::{distributions::Alphanumeric, thread_rng, Rng};
 use std::{
@@ -17,18 +19,6 @@ use std::{
 const DATA: &str = "data";
 const ENTRY: &str = "databases";
 
-#[derive(Clone)]
-pub struct Databases;
-
-impl Databases {
-    pub fn new() -> Self {
-        Self {}
-    }
-
-    fn add_database(&self, _name: &str) {
-    }
-}
-
 #[derive(Clone)]
 pub enum CacheType {
     Raw(String),
@@ -658,18 +648,6 @@ mod cache_entry {
     }
 }
 
-#[cfg(test)]
-mod databases {
-    use super::*;
-
-    #[test]
-    fn add_database() {
-        let dbs = Databases::new();
-        let name = "db1";
-        dbs.add_database(name);
-    }
-}
-
 #[cfg(test)]
 mod enum_ctype {
     use super::*;