1 files changed, 23 insertions, 0 deletions
diff --git a/config/helpers/vendor_dll_hash.js b/config/helpers/vendor_dll_hash.js
new file mode 100644
index 00000000000..cfd7be66ad3
--- /dev/null
+++ b/config/helpers/vendor_dll_hash.js
@@ -0,0 +1,23 @@
+const fs = require('fs');
+const path = require('path');
+const crypto = require('crypto');
+
+const CACHE_PATHS = [
+  './config/webpack.config.js',
+  './config/webpack.vendor.config.js',
+  './package.json',
+  './yarn.lock',
+];
+
+const resolvePath = file => path.resolve(__dirname, '../..', file);
+const readFile = file => fs.readFileSync(file);
+const fileHash = buffer =>
+  crypto
+    .createHash('md5')
+    .update(buffer)
+    .digest('hex');
+
+module.exports = () => {
+  const fileBuffers = CACHE_PATHS.map(resolvePath).map(readFile);
+  return fileHash(Buffer.concat(fileBuffers)).substr(0, 12);
+};