Fix extract on windows

fbshipit-source-id: 9c3ff60

src/Extract.js

@@ -2,31 +2,36 @@
  * @flow
  */
 
+import fs from 'fs';
 import targz from 'tar.gz';
 import path from 'path';
 import spawnAsync from '@exponent/spawn-async';
+import mkdirp from 'mkdirp';
+import rimraf from 'rimraf';
+import uuid from 'node-uuid';
 
 import * as Binaries from './Binaries';
 import UserSettings from './UserSettings';
 
 async function _extractWindowsAsync(archive: string, dir: string) {
   let dotExponentHomeDirectory = UserSettings.dotExponentHomeDirectory();
-  let tmpDir = path.join(dotExponentHomeDirectory, 'starter-app-cache', 'tmp');
-  let fileNameNoExtension;
-  if (archive.endsWith('.tar.gz')) {
-    fileNameNoExtension = path.basename(archive.substr(0, archive.length - '.tar.gz'.length));
-  } else {
-    fileNameNoExtension = path.basename(archive, path.extname(archive));
-  }
-  let tmpFile = path.join(tmpDir, `${fileNameNoExtension}.tar`);
+  let tmpDir = path.join(dotExponentHomeDirectory, 'tmp', uuid.v4());
+  mkdirp.sync(tmpDir);
   let binary = path.join(Binaries.getBinariesPath(), '7z1602-extra', '7za');
   try {
     await spawnAsync(binary, ['x', archive, '-aoa', `-o${tmpDir}`]);
-    await spawnAsync(binary, ['x', tmpFile, '-aoa', `-o${dir}`]);
+    // We don't know the resulting filename after this step, so
+    // just assume the only file in the directory is our .tar file.
+    // This should be fine since we created the directory with a random name.
+    let files = fs.readdirSync(tmpDir);
+    let outputFile = path.resolve(tmpDir, files[0]);
+    await spawnAsync(binary, ['x', outputFile, '-aoa', `-o${dir}`]);
   } catch (e) {
     console.error(e.message);
     console.error(e.stderr);
     throw e;
+  } finally {
+    rimraf.sync(tmpDir);
   }
 }