Merge 9500cdf into 1386ad7

src/emulator/download.js

@@ -2,17 +2,22 @@
 
 const FirebaseError = require("../error");
 const fs = require("fs-extra");
+const tmp = require("tmp");
 const request = require("request");
 const emulatorConstants = require("./constants");
 const utils = require("../utils");
 
+tmp.setGracefulCleanup();
+
 module.exports = (name) => {
   return new Promise((resolve, reject) => {
     utils.logLabeledBullet(name, "downloading emulator...");
     let emulator = emulatorConstants.emulators[name];
     fs.ensureDirSync(emulator.cacheDir);
+
+    let tmpFile = tmp.fileSync();
     let req = request.get(emulator.remoteUrl);
-    let writeStream = fs.createWriteStream(emulator.localPath);
+    let writeStream = fs.createWriteStream(tmpFile.name);
     req.on("error", (err) => reject(err));
     req.on("response", (response) => {
       if (response.statusCode != 200) {
@@ -21,6 +26,7 @@ module.exports = (name) => {
     });
     req.on("end", () => {
       writeStream.close();
+      fs.copySync(tmpFile.name, emulator.localPath);
       fs.chmodSync(emulator.localPath, 0o755);
       resolve();
     });