feat: support loading of new files automatically with --live

package.json

@@ -48,6 +48,7 @@
     "body-parser": "^1.18.3",
     "boxen": "^1.3.0",
     "chalk": "^2.4.2",
+    "chokidar": "^3.2.3",
     "columnify": "^1.5.4",
     "common-tags": "^1.8.0",
     "conf": "^5.0.0",
@@ -61,6 +62,7 @@
     "is-ci": "^2.0.0",
     "listr": "^0.14.3",
     "lodash.camelcase": "^4.3.0",
+    "lodash.debounce": "^4.0.8",
     "lodash.kebabcase": "^4.1.1",
     "lodash.startcase": "^4.4.0",
     "log-symbols": "^2.2.0",
@@ -88,6 +90,7 @@
     "@types/got": "^9.6.0",
     "@types/jest": "^24.0.15",
     "@types/listr": "^0.14.0",
+    "@types/lodash.debounce": "^4.0.6",
     "@types/lodash.kebabcase": "^4.1.6",
     "@types/lodash.startcase": "^4.4.6",
     "@types/prompts": "^2.0.1",

src/runtime/server.ts

@@ -8,6 +8,10 @@ import express, {
 } from 'express';
 import userAgentMiddleware from 'express-useragent';
 import nocache from 'nocache';
+import { printRouteInfo } from '../printers/start';
+import chokidar from 'chokidar';
+import debounce from 'lodash.debounce';
+import path from 'path';
 import { StartCliConfig } from '../config/start';
 import { wrapErrorInHtml } from '../utils/error-html';
 import { getDebugFunction } from '../utils/logger';
@@ -18,6 +22,7 @@ import { constructGlobalScope, functionToRoute } from './route';
 
 const debug = getDebugFunction('twilio-run:server');
 const DEFAULT_PORT = process.env.PORT || 3000;
+const RELOAD_DEBOUNCE_MS = 250;
 const DEFAULT_BODY_SIZE_LAMBDA = '6mb';
 
 function requireUncached(module: string): any {
@@ -80,8 +85,43 @@ export async function createServer(
     });
   }
 
-  const routes = await getFunctionsAndAssets(config.baseDir);
-  const routeMap = setRoutes(routes);
+  let routes = await getFunctionsAndAssets(config.baseDir);
+  let routeMap = setRoutes(routes);
+
+  if (config.live) {
+    const watcher = chokidar.watch(
+      [
+        path.join(config.baseDir, '/(functions|src)/**/*.js'),
+        path.join(config.baseDir, '/(assets|static)/**/*'),
+      ],
+      {
+        ignoreInitial: true
+      }
+    );
+
+    const reloadRoutes = async () => {
+      routes = await getFunctionsAndAssets(config.baseDir);
+      routeMap = setRoutes(routes);
+
+      await printRouteInfo(config);
+    };
+
+    // Debounce so we don't needlessly reload when multiple files are changed
+    const debouncedReloadRoutes = debounce(reloadRoutes, RELOAD_DEBOUNCE_MS);
+
+    watcher
+      .on('add', path => {
+        debug(`Reloading Routes: add @ ${path}`);
+        debouncedReloadRoutes();
+      })
+      .on('unlink', path => {
+        debug(`Reloading Routes: unlink @ ${path}`);
+        debouncedReloadRoutes();
+      });
+
+    // Clean the watcher up when exiting.
+    process.on('exit', () => watcher.close());
+  }
 
   constructGlobalScope(config);