From 52697c71676356c7b2aac898721839c99ec3444d Mon Sep 17 00:00:00 2001
From: Ben Newman <ben@meteor.com>
Date: Fri, 4 Nov 2016 18:25:00 -0400
Subject: [PATCH] Cache getProdPackageNames optimistically.

---
 tools/isobuild/meteor-npm.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/isobuild/meteor-npm.js b/tools/isobuild/meteor-npm.js
index 71451e0a1c2..90bd3ef0284 100644
--- a/tools/isobuild/meteor-npm.js
+++ b/tools/isobuild/meteor-npm.js
@@ -22,6 +22,7 @@ import {
   convert as convertColonsInPath
 } from "../utils/colon-converter.js";
 
+import { wrap as wrapOptimistic } from "optimism";
 import {
   dirtyNodeModulesDirectory,
   optimisticLStat,
@@ -133,7 +134,7 @@ meteorNpm.updateDependencies = function (packageName,
 
 // Returns a flattened dictionary of npm package names used in production,
 // or false if there is no package.json file in the parent directory.
-export function getProdPackageNames(nodeModulesDir) {
+export const getProdPackageNames = wrapOptimistic(nodeModulesDir => {
   const names = Object.create(null);
   const dirs = Object.create(null);
   const nodeModulesDirStack = [];
@@ -208,7 +209,7 @@ export function getProdPackageNames(nodeModulesDir) {
   // Concretely, this means your app needs to have a package.json file if
   // you want any npm packages to be excluded in production.
   return walk(files.pathDirname(nodeModulesDir)) && names;
-}
+});
 
 const lastRebuildJSONFilename = ".meteor-last-rebuild-version.json";