Pipeline Changes

app/src/trading/logic/calculatePrices.ts

@@ -1,9 +1,10 @@
-import { OfferContext, Next } from '../pipeline';
+import { NextFunction } from '../../util/middleware';
+import { OfferContext } from '../types'
 import { getAllItemsPrice } from '../../steam/market';
 import { ItemPrice } from '../types';
 import { AccountOptions } from '../../account/account';
 
-export default async function middleware(context: OfferContext, next: Next) {
+export default async function middleware(context: OfferContext, next: NextFunction) {
   const { processor, offer } = context;
 
   context.receiveItemsPrices = await getAllItemsPrice(offer.itemsToReceive);

app/src/trading/logic/checkOverpay.ts

@@ -1,6 +1,7 @@
-import { OfferContext, Next } from '../pipeline';
+import { NextFunction } from '../../util/middleware';
+import { OfferContext } from '../types';
 
-export default function middleware(context: OfferContext, next: Next) {
+export default function middleware(context: OfferContext, next: NextFunction) {
   context.profit = context.receivePrice - context.givePrice;
 
   const { processor, offer, profit } = context;

app/src/trading/logic/index.ts

@@ -4,13 +4,14 @@ import checkSides from './checkSides';
 import unmarketable from './unmarketable';
 import calculatePrices from './calculatePrices';
 import checkOverpay from './checkOverpay';
-import { Middleware, OfferContext } from '../pipeline';
+import { Middleware } from '../../util/middleware';
+import { OfferContext } from '../types';
 
 function thenAccept(context: OfferContext) {
   const { processor, offer } = context;
   processor.accept(offer);
 }
 
-const logic: Middleware[] = [glitched, isOwner, checkSides, unmarketable, calculatePrices, checkOverpay, thenAccept];
+const logic: Middleware<OfferContext>[] = [glitched, isOwner, checkSides, unmarketable, calculatePrices, checkOverpay, thenAccept];
 
 export default logic;

app/src/trading/types.ts

@@ -1,3 +1,5 @@
+import Processor from './processor';
+
 export interface Partner {
   getSteamID64(): string;
 }
@@ -32,3 +34,13 @@ export interface Offer {
 export interface Community {
   checkConfirmations: (callback?: (err: null | Error) => void) => void;
 }
+
+export type OfferContext = {
+  readonly processor: Processor;
+  readonly offer: Offer;
+  receiveItemsPrices: ItemPrice[];
+  receivePrice: number;
+  giveItemsPrices: ItemPrice[];
+  givePrice: number;
+  profit: number,
+};

app/src/util/middleware.ts

@@ -0,0 +1,28 @@
+
+export type NextFunction = () => Promise<void> | void;
+
+export type Middleware<T> = (context: T, next: NextFunction) => void;
+
+export default class Pipeline<T> {
+
+  constructor(private middlewares: Middleware<T>[] = []) {}
+
+  use(...middlewares: Middleware<T>[]) {
+    this.middlewares = middlewares;
+  }
+
+  add(...middlewares: Middleware<T>[]) {
+    this.middlewares.push(...middlewares);
+  }
+
+  async execute(context: T) {
+    await this.run(context, [...this.middlewares]);
+  }
+
+  private async run(context: T, middlewares: Middleware<T>[]) {
+    if (middlewares.length !== 0) {
+      const next = middlewares.shift();
+      next && await next(context, async () => await this.run(context, middlewares));
+    }
+  }
+}