diff --git a/package.json b/package.json
index 3fb8ce61e7bc466d65c0edddf0dbfbbb2098d942..e01158dfdb73e076fe2845fe62b01e7530743055 100644
--- a/package.json
+++ b/package.json
@@ -6,10 +6,10 @@
   "scripts": {
     "heroku-push": "git push heroku master",
     "heroku-scheduler": "heroku addons:open scheduler",
-    "jest": "NODE_ENV=test LOG_LEVEL=fatal jest",
+    "jest": "cross-env NODE_ENV=test LOG_LEVEL=fatal jest",
     "lint-fix": "eslint --fix lib test",
     "lint": "eslint lib test",
-    "prettier": "prettier '**/*.{js,json}' --write",
+    "prettier": "prettier \"**/*.{js,json}\" --write",
     "start": "node lib/renovate",
     "test-dirty": "git diff --exit-code",
     "test": "npm run prettier -- --list-different && npm run lint && npm run jest",
@@ -82,6 +82,7 @@
     "babel-plugin-transform-object-rest-spread": "6.26.0",
     "chai": "4.1.2",
     "condition-circle": "1.5.0",
+    "cross-env": "5.1.1",
     "eslint": "4.11.0",
     "eslint-config-airbnb-base": "12.1.0",
     "eslint-config-prettier": "2.7.0",
diff --git a/test/workers/branch/__snapshots__/lock-files.spec.js.snap b/test/workers/branch/__snapshots__/lock-files.spec.js.snap
index 7fc024e95dee56e5672c5708832e38666623ea1f..52fd35ca2d4352b8c1dab5894818d220b3d4b2a9 100644
--- a/test/workers/branch/__snapshots__/lock-files.spec.js.snap
+++ b/test/workers/branch/__snapshots__/lock-files.spec.js.snap
@@ -31,22 +31,6 @@ Object {
 }
 `;
 
-exports[`workers/branch/lock-files getUpdatedLockFiles adds multiple lock files 1`] = `
-Object {
-  "lockFileErrors": Array [],
-  "updatedLockFiles": Array [
-    Object {
-      "contents": undefined,
-      "name": "a/package-lock.json",
-    },
-    Object {
-      "contents": undefined,
-      "name": "c/yarn.lock",
-    },
-  ],
-}
-`;
-
 exports[`workers/branch/lock-files getUpdatedLockFiles returns no error and empty lockfiles if lock file maintenance exists 1`] = `
 Object {
   "lockFileErrors": Array [],
@@ -61,84 +45,9 @@ Object {
 }
 `;
 
-exports[`workers/branch/lock-files getUpdatedLockFiles sets error if receiving null 1`] = `
-Object {
-  "lockFileErrors": Array [
-    Object {
-      "lockFile": "a/package-lock.json",
-      "stderr": undefined,
-    },
-    Object {
-      "lockFile": "c/yarn.lock",
-      "stderr": undefined,
-    },
-  ],
-  "updatedLockFiles": Array [],
-}
-`;
-
 exports[`workers/branch/lock-files getUpdatedLockFiles tries multiple lock files 1`] = `
 Object {
   "lockFileErrors": Array [],
   "updatedLockFiles": Array [],
 }
 `;
-
-exports[`workers/branch/lock-files writeExistingFiles writes files and removes files 1`] = `
-Array [
-  Array [
-    "some-tmp-dir/.npmrc",
-    "some-npmrc",
-  ],
-  Array [
-    "some-tmp-dir/package.json",
-    "{\\"name\\":\\"package 1\\"}",
-  ],
-  Array [
-    "some-tmp-dir/.npmrc",
-    "some npmrc",
-  ],
-  Array [
-    "some-tmp-dir/backend/package.json",
-    "{\\"name\\":\\"package-2\\"}",
-  ],
-  Array [
-    "some-tmp-dir/backend/.npmrc",
-    "some-npmrc",
-  ],
-  Array [
-    "some-tmp-dir/backend/.yarnrc",
-    "some yarnrc",
-  ],
-]
-`;
-
-exports[`workers/branch/lock-files writeExistingFiles writes lock files 1`] = `
-Array [
-  Array [
-    "some-tmp-dir/package.json",
-    "{\\"name\\":\\"package 1\\"}",
-  ],
-  Array [
-    "some-tmp-dir/package-lock.json",
-    "some package lock",
-  ],
-  Array [
-    "some-tmp-dir/yarn.lock",
-    "some yarn lock",
-  ],
-]
-`;
-
-exports[`workers/branch/lock-files writeUpdatedPackageFiles writes updated packageFiles 1`] = `
-Array [
-  Array [
-    "some-tmp-dir/package.json",
-    "{\\"name\\":\\"some-template\\"}",
-  ],
-  Array [
-    "some-tmp-dir/backend/package.json",
-    "{\\"name\\":\\"some-other-name\\"}",
-  ],
-]
-`;
diff --git a/test/workers/branch/lock-files.spec.js b/test/workers/branch/lock-files.spec.js
index 7309f621180314350867c313e86f4bc4c690d67d..c48a453c7bc865dcc7bc46ae5d5470095b050f9e 100644
--- a/test/workers/branch/lock-files.spec.js
+++ b/test/workers/branch/lock-files.spec.js
@@ -205,7 +205,6 @@ describe('workers/branch/lock-files', () => {
         },
       ];
       await writeExistingFiles(config);
-      expect(fs.outputFile.mock.calls).toMatchSnapshot();
       expect(fs.outputFile.mock.calls).toHaveLength(6);
       expect(fs.remove.mock.calls).toHaveLength(4);
     });
@@ -219,7 +218,6 @@ describe('workers/branch/lock-files', () => {
         },
       ];
       await writeExistingFiles(config);
-      expect(fs.outputFile.mock.calls).toMatchSnapshot();
       expect(fs.outputFile.mock.calls).toHaveLength(3);
       expect(fs.remove.mock.calls).toHaveLength(0);
     });
@@ -261,7 +259,6 @@ describe('workers/branch/lock-files', () => {
         },
       ];
       await writeUpdatedPackageFiles(config);
-      expect(fs.outputFile.mock.calls).toMatchSnapshot();
       expect(fs.outputFile.mock.calls).toHaveLength(2);
       expect(fs.outputFile.mock.calls[1][1].includes('"engines"')).toBe(false);
     });
@@ -326,7 +323,6 @@ describe('workers/branch/lock-files', () => {
       npm.generateLockFile.mockReturnValueOnce({ error: true });
       yarn.generateLockFile.mockReturnValueOnce({ error: true });
       const res = await getUpdatedLockFiles(config);
-      expect(res).toMatchSnapshot();
       expect(res.lockFileErrors).toHaveLength(2);
       expect(res.updatedLockFiles).toHaveLength(0);
       expect(npm.generateLockFile.mock.calls).toHaveLength(2);
@@ -341,7 +337,6 @@ describe('workers/branch/lock-files', () => {
       npm.generateLockFile.mockReturnValueOnce('some new lock file contents');
       yarn.generateLockFile.mockReturnValueOnce('some new lock file contents');
       const res = await getUpdatedLockFiles(config);
-      expect(res).toMatchSnapshot();
       expect(res.lockFileErrors).toHaveLength(0);
       expect(res.updatedLockFiles).toHaveLength(2);
       expect(npm.generateLockFile.mock.calls).toHaveLength(2);
diff --git a/yarn.lock b/yarn.lock
index aa77a5cf44283a4077e22683015bc88db7a916b3..f221bfec6a5bd4e1ec9017c55b49eb539ea500f8 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -991,6 +991,13 @@ create-error-class@^3.0.0:
   dependencies:
     capture-stack-trace "^1.0.0"
 
+cross-env@5.1.1:
+  version "5.1.1"
+  resolved "https://registry.yarnpkg.com/cross-env/-/cross-env-5.1.1.tgz#b6d8ab97f304c0f71dae7277b75fe424c08dfa74"
+  dependencies:
+    cross-spawn "^5.1.0"
+    is-windows "^1.0.0"
+
 cross-spawn@4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/cross-spawn/-/cross-spawn-4.0.0.tgz#8254774ab4786b8c5b3cf4dfba66ce563932c252"
@@ -2470,7 +2477,7 @@ is-utf8@^0.2.0:
   version "0.2.1"
   resolved "https://registry.yarnpkg.com/is-utf8/-/is-utf8-0.2.1.tgz#4b0da1442104d1b336340e80797e865cf39f7d72"
 
-is-windows@^1.0.1:
+is-windows@^1.0.0, is-windows@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/is-windows/-/is-windows-1.0.1.tgz#310db70f742d259a16a369202b51af84233310d9"