🚨 Make ts linter less depressed

frontend/src/businessData.tsx

@@ -7,11 +7,11 @@ import { Passages, Stops } from './types';
 interface Store {
 	passages: () => Passages;
 	getLinePassages?: (lineId: string) => Passages;
-	addPassages?: (passages) => void;
+	addPassages?: (passages: Passages) => void;
 	clearPassages?: () => void;
 
 	stops: () => Stops;
-	addStops?: (stops) => void;
+	addStops?: (stops: Stops) => void;
 };
 
 export const BusinessDataContext = createContext<Store>();
@@ -22,7 +22,7 @@ export function BusinessDataProvider(props: { children: JSX.Element }) {
 
 	const [store, setStore] = createStore({ lines: {}, passages: {}, stops: {} });
 
-	async function getLine(lineId: number) {
+	const getLine: Line = async (lineId: string) => {
 		let line = store.lines[lineId];
 		if (line === undefined) {
 			console.log(`${lineId} not found... fetch it from backend.`);