fixes for Mael

__tests__/commands/install/integration-deduping.js

@@ -221,7 +221,7 @@ test.concurrent('install should not hardlink repeated dependencies if linkDuplic
   });
 });
 
-test.concurrent('install should not copy node_modules when hardlinking', (): Promise<void> => {
+test.concurrent('install should not crash when hardlinking deep structures', (): Promise<void> => {
   // https://github.com/yarnpkg/yarn/issues/2734
   // A@1 -> B@1 -> C@1
   //     -> C@2
@@ -239,13 +239,13 @@ test.concurrent('install should not copy node_modules when hardlinking', (): Pro
   });
 });
 
-test.concurrent('install should not hardlink full package structure', (): Promise<void> => {
+test.concurrent('install should consider different hoisting with --link-duplicate', (): Promise<void> => {
   // https://github.com/yarnpkg/yarn/issues/2734
   // A@1 -> B@1 -> C@1
   //     -> C@2
   // B@2
   // C@3
-  // D@1 -> B@1 (hardlink)
+  // D@1 -> B@1 (hardlink) -> *C@1* (redundant)
   //     -> C@1 (hardlink)
   return runInstall({linkDuplicates: true}, 'hardlink-collision-2', async config => {
     let a_1 = await fs.stat(path.join(config.cwd, 'node_modules/a/node_modules/b/package.json'));
@@ -254,6 +254,46 @@ test.concurrent('install should not hardlink full package structure', (): Promis
     a_1 = await fs.stat(path.join(config.cwd, 'node_modules/a/node_modules/b/node_modules/c/package.json'));
     d_1 = await fs.stat(path.join(config.cwd, 'node_modules/d/node_modules/c/package.json'));
     expect(a_1.ino).toEqual(d_1.ino);
-    expect(await fs.exists(path.join(config.cwd, 'node_modules/d/node_modules/b/node_modules/c/package.json'))).toBe(false);
+    // this is redundant but we are ok with it
+    expect(await fs.exists(path.join(config.cwd, 'node_modules/d/node_modules/b/node_modules/c/package.json'))).toBe(true);
+  });
+});
+
+test.concurrent('install should consider different hoisting with --link-duplicate 2', (): Promise<void> => {
+  // https://github.com/yarnpkg/yarn/issues/2734
+  // A@1 -> B@1
+  //     -> C@1
+  // B@2
+  // C@3
+  // D@1 -> B@1 (hardlink) -> C@1 (hardlink)
+  //     -> C@2
+  return runInstall({linkDuplicates: true}, 'hardlink-collision-3', async config => {
+    let a_1 = await fs.stat(path.join(config.cwd, 'node_modules/a/node_modules/b/package.json'));
+    let d_1 = await fs.stat(path.join(config.cwd, 'node_modules/d/node_modules/b/package.json'));
+    expect(a_1.ino).toEqual(d_1.ino);
+    a_1 = await fs.stat(path.join(config.cwd, 'node_modules/a/node_modules/c/package.json'));
+    d_1 = await fs.stat(path.join(config.cwd, 'node_modules/d/node_modules/b/node_modules/c/package.json'));
+    expect(a_1.ino).toEqual(d_1.ino);
+  });
+});
+
+test.concurrent('install should not hardlink full package structure', (): Promise<void> => {
+  // https://github.com/yarnpkg/yarn/issues/2734
+  // A@1 -> B@1 -> C@1 -> (bundle leftpad)
+  //     -> C@2
+  // B@2
+  // C@3
+  // D@1 -> B@1 (hardlink) -> C@1 (hardlink) -> (bundle leftpad) (hardlink)
+  //     -> C@2
+  return runInstall({linkDuplicates: true}, 'hardlink-collision-with-bundled', async config => {
+    let a_1 = await fs.stat(path.join(config.cwd, 'node_modules/a/node_modules/b/package.json'));
+    let d_1 = await fs.stat(path.join(config.cwd, 'node_modules/d/node_modules/b/package.json'));
+    expect(a_1.ino).toEqual(d_1.ino);
+    a_1 = await fs.stat(path.join(config.cwd, 'node_modules/a/node_modules/b/node_modules/c/package.json'));
+    d_1 = await fs.stat(path.join(config.cwd, 'node_modules/d/node_modules/b/node_modules/c/package.json'));
+    expect(a_1.ino).toEqual(d_1.ino);
+    a_1 = await fs.stat(path.join(config.cwd, 'node_modules/a/node_modules/b/node_modules/c/node_modules/left-pad/package.json'));
+    d_1 = await fs.stat(path.join(config.cwd, 'node_modules/d/node_modules/b/node_modules/c/node_modules/left-pad/package.json'));
+    expect(a_1.ino).toEqual(d_1.ino);
   });
 });

__tests__/fixtures/install/hardlink-collision-3/deps/a-1/package.json

@@ -0,0 +1,7 @@
+{
+  "name": "a",
+  "version": "1.0.0",
+  "dependencies": {
+    "b": "file:../b-1"
+  }
+}

__tests__/fixtures/install/hardlink-collision-3/deps/b-1/package.json

@@ -0,0 +1,7 @@
+{
+  "name": "b",
+  "version": "1.0.0",
+  "dependencies": {
+    "c": "file:../c-1"
+  }
+}

__tests__/fixtures/install/hardlink-collision-3/deps/b-2/package.json

@@ -0,0 +1,4 @@
+{
+  "name": "b",
+  "version": "2.0.0"
+}

__tests__/fixtures/install/hardlink-collision-3/deps/c-1/package.json

@@ -0,0 +1,4 @@
+{
+  "name": "c",
+  "version": "1.0.0"
+}

__tests__/fixtures/install/hardlink-collision-3/deps/c-2/package.json

@@ -0,0 +1,4 @@
+{
+  "name": "c",
+  "version": "2.0.0"
+}

__tests__/fixtures/install/hardlink-collision-3/deps/c-3/package.json

@@ -0,0 +1,4 @@
+{
+  "name": "c",
+  "version": "3.0.0"
+}

__tests__/fixtures/install/hardlink-collision-3/deps/d-1/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "a",
+  "version": "2.0.0",
+  "dependencies": {
+    "b": "file:../b-1",
+    "c": "file:../c-2"
+  }
+}

__tests__/fixtures/install/hardlink-collision-3/package.json

@@ -0,0 +1,8 @@
+{
+  "dependencies": {
+    "a": "file:deps/a-1",
+    "b": "file:deps/b-2",
+    "c": "file:deps/c-3",
+    "d": "file:deps/d-1"
+  }
+}

__tests__/fixtures/install/hardlink-collision-with-bundled/deps/a-1/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "a",
+  "version": "1.0.0",
+  "dependencies": {
+    "b": "file:../b-1",
+    "c": "file:../c-2"
+  }
+}

__tests__/fixtures/install/hardlink-collision-with-bundled/deps/b-1/package.json

@@ -0,0 +1,7 @@
+{
+  "name": "b",
+  "version": "1.0.0",
+  "dependencies": {
+    "c": "file:../c-1/c-1.0.0.tgz"
+  }
+}

__tests__/fixtures/install/hardlink-collision-with-bundled/deps/b-2/package.json

@@ -0,0 +1,4 @@
+{
+  "name": "b",
+  "version": "2.0.0"
+}

__tests__/fixtures/install/hardlink-collision-with-bundled/deps/c-2/package.json

@@ -0,0 +1,4 @@
+{
+  "name": "c",
+  "version": "2.0.0"
+}

__tests__/fixtures/install/hardlink-collision-with-bundled/deps/c-3/package.json

@@ -0,0 +1,4 @@
+{
+  "name": "c",
+  "version": "3.0.0"
+}

__tests__/fixtures/install/hardlink-collision-with-bundled/deps/d-1/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "a",
+  "version": "2.0.0",
+  "dependencies": {
+    "b": "file:../b-1",
+    "c": "file:../c-2"
+  }
+}

__tests__/fixtures/install/hardlink-collision-with-bundled/package.json

@@ -0,0 +1,8 @@
+{
+  "dependencies": {
+    "a": "file:deps/a-1",
+    "b": "file:deps/b-2",
+    "c": "file:deps/c-3",
+    "d": "file:deps/d-1"
+  }
+}

src/fetchers/tarball-fetcher.js

@@ -14,6 +14,7 @@ const url = require('url');
 const fs = require('fs');
 const stream = require('stream');
 const gunzip = require('gunzip-maybe');
+import {removePrefix} from '../util/misc.js';
 
 export default class TarballFetcher extends BaseFetcher {
   async setupMirrorFromCache(): Promise<?string> {
@@ -174,13 +175,16 @@ export default class TarballFetcher extends BaseFetcher {
   }
 
   async _fetch(): Promise<FetchedOverride> {
+    const isFilePath = this.reference.startsWith('file:');
+    this.reference = removePrefix(this.reference, 'file:');
     const urlParse = url.parse(this.reference);
 
-    const isFilePath = urlParse.protocol
+    // legacy support for local paths in yarn.lock entries
+    const isRelativePath = urlParse.protocol
       ? urlParse.protocol.match(/^[a-z]:$/i)
       : urlParse.pathname ? urlParse.pathname.match(/^(?:\.{1,2})?[\\\/]/) : false;
 
-    if (isFilePath) {
+    if (isFilePath || isRelativePath) {
       return this.fetchFromLocal(this.reference);
     }
 

src/resolvers/exotics/tarball-resolver.js

@@ -5,7 +5,6 @@ import type PackageRequest from '../../package-request.js';
 import TarballFetcher from '../../fetchers/tarball-fetcher.js';
 import ExoticResolver from './exotic-resolver.js';
 import Git from './git-resolver.js';
-import {removePrefix} from '../../util/misc.js';
 import guessName from '../../util/guess-name.js';
 import * as versionUtil from '../../util/version.js';
 import * as crypto from '../../util/crypto.js';
@@ -52,7 +51,7 @@ export default class TarballResolver extends ExoticResolver {
       return shrunk;
     }
 
-    const url = removePrefix(this.url, 'file:');
+    const url = this.url;
     let {hash, registry} = this;
     let pkgJson;
 

src/util/fs.js

@@ -360,6 +360,11 @@ async function buildActionsForHardlink(
     const {src, dest} = data;
     const onFresh = data.onFresh || noop;
     const onDone = data.onDone || noop;
+    if (files.has(dest)) {
+      // don't hardlink a file twice
+      onDone();
+      return;
+    }
     files.add(dest);
 
     if (events.ignoreBasenames.indexOf(path.basename(src)) >= 0) {
@@ -450,7 +455,6 @@ async function buildActionsForHardlink(
 
       // push all files to queue
       invariant(srcFiles, 'src files not initialised');
-      srcFiles = srcFiles.filter(f => f !== 'node_modules');
       let remaining = srcFiles.length;
       if (!remaining) {
         onDone();