Use process.env.JEST_WORKER_ID

Author: CvX

jest/runInTempDirectory.js

@@ -5,8 +5,8 @@ import rimraf from 'rimraf'
 
 export default function(callback) {
   return new Promise(resolve => {
-    const timestamp = new Date().valueOf()
-    const tmpPath = path.resolve(__dirname, `../__tmp_${timestamp}`)
+    const workerId = process.env.JEST_WORKER_ID
+    const tmpPath = path.resolve(__dirname, `../__tmp_${workerId}`)
     const currentPath = process.cwd()
 
     rimraf.sync(tmpPath)