Fix tarball file (#3221)

* Fixes #3168

* Adds tests

* Fixes linting

__tests__/commands/install/lockfiles.js

@@ -15,6 +15,12 @@ const fsNode = require('fs');
 const path = require('path');
 const os = require('os');
 
+test.concurrent('does fetch files from the local filesystem', (): Promise<void> => {
+  return runInstall({}, 'install-should-fetch-local-tarballs', (config): Promise<void> => {
+    return Promise.resolve();
+  });
+});
+
 test.concurrent("doesn't write new lockfile if existing one satisfied", (): Promise<void> => {
   return runInstall({}, 'install-dont-write-lockfile-if-satisfied', async (config): Promise<void> => {
     const lockfile = await fs.readFile(path.join(config.cwd, 'yarn.lock'));

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

@@ -0,0 +1,6 @@
+{
+  "license": "MIT",
+  "dependencies": {
+    "fake-dependency": "./fake-dependency-1.0.1.tgz"
+  }
+}

src/fetchers/tarball-fetcher.js

@@ -106,7 +106,7 @@ export default class TarballFetcher extends BaseFetcher {
     const tarballMirrorPath = this.getTarballMirrorPath();
     const tarballCachePath = this.getTarballCachePath();
 
-    const tarballPath = override || tarballMirrorPath || tarballCachePath;
+    const tarballPath = path.resolve(this.config.cwd, override || tarballMirrorPath || tarballCachePath);
 
     if (!tarballPath || !await fsUtil.exists(tarballPath)) {
       throw new MessageError(this.config.reporter.lang('tarballNotInNetworkOrCache', this.reference, tarballPath));
@@ -178,6 +178,12 @@ export default class TarballFetcher extends BaseFetcher {
   }
 
   async _fetch(): Promise<FetchedOverride> {
+    const urlParse = url.parse(this.reference);
+
+    if (urlParse.protocol === null && urlParse.pathname.match(/^\.\.?[\/\\]/)) {
+      return await this.fetchFromLocal(this.reference);
+    }
+
     if (await this.getLocalAvailabilityStatus()) {
       return await this.fetchFromLocal();
     } else {