feat(proxy-server): export proxy middlewares (#3361)

packages/netlify-cms-proxy-server/src/index.ts

@@ -1,7 +1,6 @@
 require('dotenv').config();
 import express from 'express';
-import morgan from 'morgan';
-import cors from 'cors';
+import { registerCommonMiddlewares } from './middlewares/common';
 import { registerMiddleware as registerLocalGit } from './middlewares/localGit';
 import { registerMiddleware as registerLocalFs } from './middlewares/localFs';
 
@@ -9,9 +8,7 @@ const app = express();
 const port = process.env.PORT || 8081;
 
 (async () => {
-  app.use(morgan('combined'));
-  app.use(cors());
-  app.use(express.json({ limit: '50mb' }));
+  registerCommonMiddlewares(app);
 
   try {
     const mode = process.env.MODE || 'fs';

packages/netlify-cms-proxy-server/src/middlewares.ts

@@ -0,0 +1,14 @@
+import express from 'express';
+import { registerCommonMiddlewares } from './middlewares/common';
+import { registerMiddleware as localGit } from './middlewares/localGit';
+import { registerMiddleware as localFs } from './middlewares/localFs';
+
+export const registerLocalGit = async (app: express.Express) => {
+  registerCommonMiddlewares(app);
+  await localGit(app);
+};
+
+export const registerLocalFs = async (app: express.Express) => {
+  registerCommonMiddlewares(app);
+  await localFs(app);
+};

packages/netlify-cms-proxy-server/src/middlewares/common/index.ts

@@ -0,0 +1,9 @@
+import express from 'express';
+import morgan from 'morgan';
+import cors from 'cors';
+
+export const registerCommonMiddlewares = (app: express.Express) => {
+  app.use(morgan('combined'));
+  app.use(cors());
+  app.use(express.json({ limit: '50mb' }));
+};