From 78b1e3bb4398b325f5ed1c74b30ac312c130300d Mon Sep 17 00:00:00 2001
From: Krystian Sz <sztadii@gmail.com>
Date: Mon, 24 Jun 2024 07:41:18 +0700
Subject: [PATCH] Create TransportService to unify all related services

---
 src/services.ts | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/services.ts b/src/services.ts
index bf34c72..50b11fc 100644
--- a/src/services.ts
+++ b/src/services.ts
@@ -8,7 +8,14 @@ import {
   metroStationFares
 } from './config'
 
-export class BusService {
+interface TransportService {
+  getTransactionCharge(
+    transaction?: Transaction,
+    lastTransaction?: Transaction
+  ): number
+}
+
+export class BusService implements TransportService {
   private fares: BusFares
 
   constructor(fares?: Partial<BusFares>) {
@@ -20,7 +27,7 @@ export class BusService {
   }
 }
 
-export class MetroService {
+export class MetroService implements TransportService {
   private fares: MetroStationFares
 
   constructor(fares?: Partial<MetroStationFares>) {