Don't compute integrity when network restricted (#6248)

* Fixes git repositories w/ --offline

* test(integrity): do not update in offline mode

Author: arcanis

__tests__/commands/_helpers.js

@@ -91,6 +91,7 @@ export function makeConfigFromDirectory(cwd: string, reporter: Reporter, flags:
       prefix: flags.prefix,
       production: flags.production,
       updateChecksums: !!flags.updateChecksums,
+      offline: !!flags.offline,
       focus: !!flags.focus,
       enableDefaultRc: !flags.noDefaultRc,
       extraneousYarnrcFiles: flags.useYarnrc,

__tests__/commands/install/integration.js

@@ -738,6 +738,11 @@ test('install should create integrity field if not present', () =>
     // backwards-compatibility
   }));
 
+test('install should not create integrity field if not present and in offline mode', () =>
+  runInstall({offline: true}, 'install-update-auth-no-offline-integrity', async config => {
+    expect(await fs.exists(path.join(config.cwd, 'node_modules', 'abab'))).toEqual(true);
+  }));
+
 test('install should ignore existing hash if integrity is present even if it fails to authenticate it', () =>
   expect(runInstall({}, 'install-update-auth-bad-sha512-good-hash')).rejects.toMatchObject({
     message: expect.stringContaining("computed integrity doesn't match our records"),

__tests__/fixtures/install/install-update-auth-no-offline-integrity/.yarnrc

@@ -0,0 +1 @@
+yarn-offline-mirror "./offline-mirror"

__tests__/fixtures/install/install-update-auth-no-offline-integrity/offline-mirror/abab-2.0.0.tgz

@@ -0,0 +1,9 @@
+{
+  "name": "install-update-auth-no-offline-integrity",
+  "version": "1.0.0",
+  "main": "index.js",
+  "license": "MIT",
+  "dependencies": {
+    "abab": "^2.0.0"
+  }
+}

__tests__/fixtures/install/install-update-auth-no-offline-integrity/package.json

@@ -0,0 +1,7 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+abab@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/abab/-/abab-2.0.0.tgz#aba0ab4c5eee2d4c79d3487d85450fb2376ebb0f"

__tests__/fixtures/install/install-update-auth-no-offline-integrity/yarn.lock

@@ -207,8 +207,8 @@ export default class NpmResolver extends RegistryResolver {
         }
       }
     }
-    if (shrunk && shrunk._remote && shrunk._remote.integrity) {
-      // if the integrity field does not exist, it needs to be created
+    if (shrunk && shrunk._remote && (shrunk._remote.integrity || this.config.offline)) {
+      // if the integrity field does not exist and we're not network-restricted, it needs to be created
       return shrunk;
     }