feat(twilio-run:start): make ngrok optional and handle failure (#207)

This is intended to help with #205. Still need to investigate installing CLI plugins without optional dependencies.

Author: philnash

packages/twilio-run/__tests__/config/start.withoutNgrok.test.ts

@@ -0,0 +1,33 @@
+import { getUrl, StartCliFlags } from '../../src/config/start';
+
+jest.mock('ngrok', () => {
+  throw new Error("Cannot find module 'ngrok'");
+});
+
+describe('getUrl', () => {
+  test('calls ngrok if ngrok is defined', async () => {
+    const config = ({
+      ngrok: '',
+    } as unknown) as StartCliFlags;
+
+    expect.assertions(1);
+    try {
+      await getUrl(config, 3000);
+    } catch (error) {
+      expect(error.message).toMatch("Cannot find module 'ngrok'");
+    }
+  });
+
+  test('calls ngrok with custom subdomain if passed', async () => {
+    const config = ({
+      ngrok: 'dom',
+    } as unknown) as StartCliFlags;
+
+    expect.assertions(1);
+    try {
+      await getUrl(config, 3000);
+    } catch (error) {
+      expect(error.message).toMatch("Cannot find module 'ngrok'");
+    }
+  });
+});

packages/twilio-run/package.json

@@ -62,7 +62,6 @@
     "lodash.kebabcase": "^4.1.1",
     "lodash.startcase": "^4.4.0",
     "log-symbols": "^2.2.0",
-    "ngrok": "^3.0.1",
     "nocache": "^2.1.0",
     "normalize.css": "^8.0.1",
     "ora": "^3.3.1",
@@ -76,6 +75,9 @@
     "wrap-ansi": "^5.1.0",
     "yargs": "^13.2.2"
   },
+  "optionalDependencies": {
+    "ngrok": "^3.3.0"
+  },
   "devDependencies": {
     "@types/cheerio": "^0.22.12",
     "@types/common-tags": "^1.8.0",

packages/twilio-run/src/commands/start.ts

@@ -1,5 +1,6 @@
 import inquirer from 'inquirer';
 import { Argv } from 'yargs';
+import { Server } from 'http';
 import checkNodejsVersion from '../checks/nodejs-version';
 import checkProjectStructure from '../checks/project-structure';
 import { getConfigFromCli, StartCliFlags } from '../config/start';
@@ -71,6 +72,7 @@ export async function handler(
   }
 
   const app = await createServer(config.port, config);
+  let server: Server;
   debug('Start server on port %d', config.port);
   return new Promise((resolve, reject) => {
     let attempts = 1;
@@ -80,9 +82,18 @@ export async function handler(
         if (port) {
           config.port = port;
         }
-        config.url = await getUrl(argv, config.port);
-        printRouteInfo(config);
-        resolve();
+        try {
+          config.url = await getUrl(argv, config.port);
+          printRouteInfo(config);
+          resolve();
+        } catch (error) {
+          server.close(() => {
+            logger.info(
+              'ngrok could not be started because the module is not installed. Please install optional dependencies and try again.'
+            );
+            process.exit(1);
+          });
+        }
       };
     };
     const handleServerError = async (error: ServerError) => {
@@ -101,7 +112,7 @@ export async function handler(
             },
           ]);
           attempts += 1;
-          const server = app.listen(
+          server = app.listen(
             answers.newPortNumber,
             serverStartedSuccessfully(answers.newPortNumber)
           );
@@ -112,7 +123,7 @@ export async function handler(
       }
     };
 
-    const server = app.listen(config.port, serverStartedSuccessfully());
+    server = app.listen(config.port, serverStartedSuccessfully());
     server.on('error', handleServerError);
   });
 }