Allow Node.js to work with https (#2667)

Detect the protocol and pick the right module as needed.

Fixes #2613

js/noms/package.json

@@ -38,6 +38,7 @@
     "flow-bin": "^0.32.0",
     "fs-extra": "^0.30.0",
     "mocha": "^2.5.3",
+    "mock-require": "^1.3.0",
     "nyc": "^8.3.0"
   },
   "scripts": {

js/noms/src/fetch-test.js

@@ -0,0 +1,44 @@
+// @flow
+
+// Copyright 2016 Attic Labs, Inc. All rights reserved.
+// Licensed under the Apache License, version 2.0:
+// http://www.apache.org/licenses/LICENSE-2.0
+
+import {assert} from 'chai';
+import {suite, test, setup, teardown} from 'mocha';
+import mock from 'mock-require';
+
+suite('fetch', () => {
+  let log;
+
+  setup(() => {
+    log = [];
+    for (const protocol of ['http', 'https']) {
+      mock(protocol, {
+        request(options) {
+          log.push(protocol, options.href);
+          return {
+            end() {},
+            on() {},
+            setTimeout() {},
+          };
+        },
+      });
+    }
+  });
+
+  teardown(() => {
+    mock.stopAll();
+  });
+
+  test('http vs https', () => {
+    const {fetchText} = mock.reRequire('./fetch.js');
+
+    fetchText('http://example.com');
+    assert.deepEqual(log, ['http', 'http://example.com/']);
+
+    log = [];
+    fetchText('https://example.com');
+    assert.deepEqual(log, ['https', 'https://example.com/']);
+  });
+});

js/noms/src/fetch.js

@@ -4,7 +4,8 @@
 // Licensed under the Apache License, version 2.0:
 // http://www.apache.org/licenses/LICENSE-2.0
 
-import {request} from 'http';
+import * as http from 'http';
+import * as https from 'https';
 import {parse} from 'url';
 import * as Bytes from './bytes.js';
 
@@ -27,6 +28,11 @@ function objectToMap<T>(object: {[key: string]: T}): Map<string, T> {
   return m;
 }
 
+const requestModules = {
+  'http:': http,
+  'https:': https,
+};
+
 function fetch(url: string, options: FetchOptions = {}): Promise<BufResponse> {
   const opts: any = parse(url);
   opts.method = options.method || 'GET';
@@ -34,7 +40,7 @@ function fetch(url: string, options: FetchOptions = {}): Promise<BufResponse> {
     opts.headers = options.headers;
   }
   return new Promise((resolve, reject) => {
-    const req = request(opts, res => {
+    const req = requestModules[opts.protocol].request(opts, res => {
       if (res.statusCode < 200 || res.statusCode >= 300) {
         reject(new Error(`HTTP Error: ${res.statusCode}`));
         return;
@@ -72,7 +78,7 @@ function fetch(url: string, options: FetchOptions = {}): Promise<BufResponse> {
     // then catch that event and report an error.
     req.setTimeout(2 * 60 * 1000, () => req.abort());
     req.on('abort', () => {
-      reject(new Error('HTTP request timed out'));
+      reject(new Error('Request timed out'));
     });
 
     if (options.body) {