Add scaffolding of the index usage test

src/backup.rs

@@ -47,3 +47,16 @@ impl<'a> Engine<'a> {
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod should {
+
+    #[test]
+    fn store_file_where_index_tells_it() {
+        // fake index, all files stores at the same path
+        // backup
+        // see if repo contains one file at the faked path
+        assert!(false);
+    }
+
+}

src/storage.rs

@@ -35,7 +35,7 @@ impl<'a> Index<'a> {
     fn new() -> Self {
         Self {
             file_hashes: HashMap::new(),
-            file_paths: HashMap::new()
+            file_paths: HashMap::new(),
         }
     }
 
@@ -78,7 +78,7 @@ impl<'a> Index<'a> {
                     source_paths.insert(source_path.to_string());
                     IndexHashEntry {
                         source_paths,
-                        storage_path: old_entry.storage_path.clone()
+                        storage_path: old_entry.storage_path.clone(),
                     }
                 },
             )