From 544d54c72a3d7099491bae97e1915e738e463331 Mon Sep 17 00:00:00 2001
From: Rhys Arkins <rhys@arkins.net>
Date: Sat, 10 Apr 2021 06:38:26 +0200
Subject: [PATCH] feat(npm): retain npmrc lines without variables

---
 lib/manager/npm/extract/index.spec.ts |  6 +++---
 lib/manager/npm/extract/index.ts      | 10 ++++++++--
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/lib/manager/npm/extract/index.spec.ts b/lib/manager/npm/extract/index.spec.ts
index 79653416cc962c..1917c158bcec20 100644
--- a/lib/manager/npm/extract/index.spec.ts
+++ b/lib/manager/npm/extract/index.spec.ts
@@ -126,11 +126,11 @@ describe('manager/npm/extract', () => {
       );
       expect(res.npmrc).toBeUndefined();
     });
-    it('finds and discards .npmrc', async () => {
+    it('finds and filters .npmrc with variables', async () => {
       fs.readLocalFile = jest.fn((fileName) => {
         if (fileName === '.npmrc') {
           // eslint-disable-next-line
-          return '//registry.npmjs.org/:_authToken=${NPM_AUTH_TOKEN}\n';
+          return 'registry=https://registry.npmjs.org\n//registry.npmjs.org/:_authToken=${NPM_AUTH_TOKEN}\n';
         }
         return null;
       });
@@ -139,7 +139,7 @@ describe('manager/npm/extract', () => {
         'package.json',
         {}
       );
-      expect(res.npmrc).toEqual('');
+      expect(res.npmrc).toEqual('registry=https://registry.npmjs.org\n');
     });
     it('finds lerna', async () => {
       fs.readLocalFile = jest.fn((fileName) => {
diff --git a/lib/manager/npm/extract/index.ts b/lib/manager/npm/extract/index.ts
index cbc04c1596e629..7d745f386604d9 100644
--- a/lib/manager/npm/extract/index.ts
+++ b/lib/manager/npm/extract/index.ts
@@ -106,8 +106,14 @@ export async function extractPackageFile(
         npmrc = npmrc.replace(/(^|\n)package-lock.*?(\n|$)/g, '\n');
       }
       if (npmrc.includes('=${') && !getAdminConfig().exposeAllEnv) {
-        logger.debug('Overriding .npmrc file with variables');
-        npmrc = '';
+        logger.debug(
+          { npmrcFileName },
+          'Stripping .npmrc file of lines with variables'
+        );
+        npmrc = npmrc
+          .split('\n')
+          .filter((line) => !line.includes('=${'))
+          .join('\n');
       }
     }
   }