fix downloadApp

lib/helpers.js

@@ -7,7 +7,7 @@ import B from 'bluebird';
 import { tempDir, system, fs } from 'appium-support';
 import { exec } from 'teen_process';
 import AdmZip from 'adm-zip';
-import request from 'request-promise';
+import requestWithoutPromises from 'request';
 
 const ZIP_EXTS = ['.zip', '.ipa'];
 
@@ -57,13 +57,24 @@ async function downloadApp (app, appExt) {
 }
 
 async function downloadFile (fileUrl, suffix) {
+
   // We will be downloading the files to a directory, so make sure it's there
   // This step is not required if you have manually created the directory
   let fileInfo = await tempDir.open({prefix: 'appium-app', suffix: suffix});
   _fs.close(fileInfo.fd);
-  await fs.writeFile(fileInfo.path, await request(fileUrl));
-  logger.debug(`${fileUrl} downloaded to ${fileInfo.path}`);
 
+  // we use the non-promise version of request because the 'pipe' function
+  // won't overuse memory. request-promise has to store the whole response
+  // in memory (and also has encoding trickiness)
+  let writeStream = _fs.createWriteStream(fileInfo.path);
+  writeStream.on('error', (e) => logger.errorAndThrow(e));
+
+  let onClose = B.promisify(writeStream.on, writeStream)('close');
+
+  requestWithoutPromises.get(fileUrl).pipe(writeStream);
+
+  await onClose;
+  logger.debug(`${fileUrl} downloaded to ${fileInfo.path}`);
   return fileInfo.path;
 }
 

package.json

@@ -31,7 +31,7 @@
     "bluebird": "^2.9.25",
     "lodash": "^3.9.1",
     "mobile-json-wire-protocol": "latest",
-    "request-promise": "^0.4.2",
+    "request": "^2.61.0",
     "source-map-support": "^0.3.2",
     "teen_process": "^1.2.2",
     "uuid-js": "^0.7.5",
@@ -49,6 +49,7 @@
     "chai-as-promised": "^5.0.0",
     "gulp": "^3.8.11",
     "mochawait": "^2.0.0",
+    "request-promise": "^0.4.2",
     "sinon": "^1.14.1",
     "yargs": "^3.9.0"
   }