Fix offline resolution (#3311)

Author: arcanis

__tests__/commands/install/lockfiles.js

@@ -15,9 +15,11 @@ const fsNode = require('fs');
 const path = require('path');
 const os = require('os');
 
-test.concurrent('does fetch files from the local filesystem', (): Promise<void> => {
+test('does fetch files from the local filesystem', (): Promise<void> => {
   return runInstall({}, 'install-should-fetch-local-tarballs', (config): Promise<void> => {
     return Promise.resolve();
+  }, async (cwd) => {
+    await fs.writeFile(`${cwd}/package.json`, (await fs.readFile(`${cwd}/package.json`)).replace(/%%CWD%%/g, cwd));
   });
 });
 

__tests__/fixtures/install/install-should-fetch-local-tarballs/@fakescope-fake-dependency-1.0.1.tgz renamed to __tests__/fixtures/install/install-should-fetch-local-tarballs/fakescope-fake-dependency-1.0.1.tgz

@@ -1,6 +1,7 @@
 {
   "license": "MIT",
   "dependencies": {
-    "fake-dependency": "./fake-dependency-1.0.1.tgz"
+    "fake-dependency": "./fake-dependency-1.0.1.tgz",
+    "@fakescope/fake-dependency": "%%CWD%%/fakescope-fake-dependency-1.0.1.tgz"
   }
 }

__tests__/fixtures/install/install-should-fetch-local-tarballs/package.json

@@ -180,7 +180,7 @@ export default class TarballFetcher extends BaseFetcher {
   async _fetch(): Promise<FetchedOverride> {
     const urlParse = url.parse(this.reference);
 
-    if (urlParse.protocol === null && urlParse.pathname.match(/^\.\.?[\/\\]/)) {
+    if (urlParse.protocol === null && urlParse.pathname.match(/^(?=(?:\.{1,2}|[a-z]:)?[\\\/])/i)) {
       return await this.fetchFromLocal(this.reference);
     }