From 7102c7d5ade6bc70fd277139da54953c4833b762 Mon Sep 17 00:00:00 2001
From: vanuan <vanuan@gmail.com>
Date: Fri, 12 May 2017 18:13:45 +0300
Subject: [PATCH] Fix #1874 race condition

Use file locking to fix the race condition when writing the cache
---
 packages/jest-runtime/package.json             |  1 +
 packages/jest-runtime/src/ScriptTransformer.js |  7 +++++++
 packages/jest-runtime/yarn.lock                | 11 +++++++++++
 3 files changed, 19 insertions(+)

diff --git a/packages/jest-runtime/package.json b/packages/jest-runtime/package.json
index ddf33d2a5b8c..1e9b6fe05d13 100644
--- a/packages/jest-runtime/package.json
+++ b/packages/jest-runtime/package.json
@@ -21,6 +21,7 @@
     "jest-util": "^20.0.1",
     "json-stable-stringify": "^1.0.1",
     "micromatch": "^2.3.11",
+    "proper-lockfile": "^2.0.1",
     "strip-bom": "3.0.0",
     "yargs": "^7.0.2"
   },
diff --git a/packages/jest-runtime/src/ScriptTransformer.js b/packages/jest-runtime/src/ScriptTransformer.js
index 5d561145017f..88b321c824b3 100644
--- a/packages/jest-runtime/src/ScriptTransformer.js
+++ b/packages/jest-runtime/src/ScriptTransformer.js
@@ -20,6 +20,7 @@ const path = require('path');
 const vm = require('vm');
 const {createDirectory} = require('jest-util');
 const fs = require('graceful-fs');
+const lockfile = require('proper-lockfile');
 const {getCacheFilePath} = require('jest-haste-map');
 const stableStringify = require('json-stable-stringify');
 const slash = require('slash');
@@ -342,8 +343,11 @@ const stripShebang = content => {
 };
 
 const writeCacheFile = (cachePath: Path, fileData: string) => {
+  let release;
   try {
+    release = lockfile.lockSync(cachePath, {realpath: false});
     fs.writeFileSync(cachePath, fileData, 'utf8');
+    release();
   } catch (e) {
     e.message =
       'jest: failed to cache transform results in: ' +
@@ -351,6 +355,9 @@ const writeCacheFile = (cachePath: Path, fileData: string) => {
       '\nFailure message: ' +
       e.message;
     removeFile(cachePath);
+    if (release) {
+      release();
+    }
     throw e;
   }
 };
diff --git a/packages/jest-runtime/yarn.lock b/packages/jest-runtime/yarn.lock
index c0121df49acf..4eaff6853f6d 100644
--- a/packages/jest-runtime/yarn.lock
+++ b/packages/jest-runtime/yarn.lock
@@ -654,6 +654,13 @@ private@^0.1.6:
   version "0.1.7"
   resolved "https://registry.yarnpkg.com/private/-/private-0.1.7.tgz#68ce5e8a1ef0a23bb570cc28537b5332aba63ef1"
 
+proper-lockfile@^2.0.1:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/proper-lockfile/-/proper-lockfile-2.0.1.tgz#159fb06193d32003f4b3691dd2ec1a634aa80d1d"
+  dependencies:
+    graceful-fs "^4.1.2"
+    retry "^0.10.0"
+
 randomatic@^1.1.3:
   version "1.1.6"
   resolved "https://registry.yarnpkg.com/randomatic/-/randomatic-1.1.6.tgz#110dcabff397e9dcff7c0789ccc0a49adf1ec5bb"
@@ -713,6 +720,10 @@ require-main-filename@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/require-main-filename/-/require-main-filename-1.0.1.tgz#97f717b69d48784f5f526a6c5aa8ffdda055a4d1"
 
+retry@^0.10.0:
+  version "0.10.1"
+  resolved "https://registry.yarnpkg.com/retry/-/retry-0.10.1.tgz#e76388d217992c252750241d3d3956fed98d8ff4"
+
 "semver@2 || 3 || 4 || 5", semver@^5.3.0:
   version "5.3.0"
   resolved "https://registry.yarnpkg.com/semver/-/semver-5.3.0.tgz#9b2ce5d3de02d17c6012ad326aa6b4d0cf54f94f"