Implements require.resolve's paths options (#6565)

* Update generate-pnp-map-api.tpl.js

* Updates the changelog

* Adds tests

* Scopes the option tests to >=8.9.0

CHANGELOG.md

@@ -40,6 +40,10 @@ Please add one entry in this file for each change in Yarn's behavior. Use the sa
 
   [#6562](https://github.com/yarnpkg/yarn/pull/6562) - [**Bertrand Marron**](https://github.com/tusbar)
 
+- Fixes `require.resolve` when used together with the `paths` option
+
+  [#6565](https://github.com/yarnpkg/yarn/pull/6565) - [**Maël Nison**](https://twitter.com/arcanis)
+
 ## 1.12.0
 
 - Adds initial support for PnP on Windows

packages/pkg-tests/pkg-tests-specs/package.json

@@ -4,6 +4,7 @@
     "main": "./sources/index.js",
     "dependencies": {
         "fs-extra": "^7.0.0",
-        "pkg-tests-core": "1.0.0"
+        "pkg-tests-core": "1.0.0",
+        "semver": "^5.6.0"
     }
 }

packages/pkg-tests/pkg-tests-specs/sources/pnp.js

@@ -1,6 +1,7 @@
 const cp = require('child_process');
 const {existsSync, statSync, stat, rename, readdir, remove} = require('fs-extra');
 const {relative, isAbsolute} = require('path');
+const {satisfies} = require('semver');
 
 const {
   fs: {createTemporaryFolder, readFile, readJson, writeFile, writeJson},
@@ -460,6 +461,110 @@ module.exports = makeTemporaryEnv => {
       ),
     );
 
+    if (satisfies(process.versions.node, `>=8.9.0`)) {
+      test(
+        `it should support the 'paths' option from require.resolve (same dependency tree)`,
+        makeTemporaryEnv(
+          {
+            private: true,
+            workspaces: [`workspace-*`],
+          },
+          {
+            plugNPlay: true,
+          },
+          async ({path, run, source}) => {
+            await writeJson(`${path}/workspace-a/package.json`, {
+              name: `workspace-a`,
+              version: `1.0.0`,
+              dependencies: {[`no-deps`]: `1.0.0`},
+            });
+
+            await writeJson(`${path}/workspace-b/package.json`, {
+              name: `workspace-b`,
+              version: `1.0.0`,
+              dependencies: {[`no-deps`]: `2.0.0`, [`one-fixed-dep`]: `1.0.0`},
+            });
+
+            await run(`install`);
+
+            await expect(
+              source(
+                `require(require.resolve('no-deps', {paths: ${JSON.stringify([
+                  `${path}/workspace-a`,
+                  `${path}/workspace-b`,
+                ])}}))`,
+              ),
+            ).resolves.toMatchObject({
+              name: `no-deps`,
+              version: `1.0.0`,
+            });
+          },
+        ),
+      );
+
+      // Skipped because not supported (we can't require files from within other dependency trees, since we couldn't
+      // reconcile them together: dependency tree A could think that package X has deps Y@1 while dependency tree B
+      // could think that X has deps Y@2 instead. Since they would share the same location on the disk, PnP wouldn't
+      // be able to tell which one should be used)
+      test.skip(
+        `it should support the 'paths' option from require.resolve (different dependency trees)`,
+        makeTemporaryEnv(
+          {
+            dependencies: {},
+          },
+          {
+            plugNPlay: true,
+          },
+          async ({path, run, source}) => {
+            await run(`install`);
+
+            const tmpA = await createTemporaryFolder();
+            const tmpB = await createTemporaryFolder();
+
+            await writeJson(`${tmpA}/package.json`, {
+              dependencies: {[`no-deps`]: `1.0.0`},
+            });
+
+            await writeJson(`${tmpB}/package.json`, {
+              dependencies: {[`no-deps`]: `2.0.0`, [`one-fixed-dep`]: `1.0.0`},
+            });
+
+            await run(`install`, {
+              cwd: tmpA,
+            });
+
+            await run(`install`, {
+              cwd: tmpB,
+            });
+
+            await expect(
+              source(`require(require.resolve('no-deps', {paths: ${JSON.stringify([tmpA, tmpB])}}))`),
+            ).resolves.toMatchObject({
+              name: `no-deps`,
+              version: `1.0.0`,
+            });
+          },
+        ),
+      );
+
+      test(
+        `using require.resolve with unsupported options should throw`,
+        makeTemporaryEnv(
+          {
+            dependencies: {[`no-deps`]: `1.0.0`},
+          },
+          {
+            plugNPlay: true,
+          },
+          async ({path, run, source}) => {
+            await run(`install`);
+
+            await expect(source(`require.resolve('no-deps', {foobar: 42})`)).rejects.toBeTruthy();
+          },
+        ),
+      );
+    }
+
     test(
       `it should load the index.js file when loading from a folder`,
       makeTemporaryEnv({}, {plugNPlay: true}, async ({path, run, source}) => {

packages/pkg-tests/yarn.lock

@@ -3150,6 +3150,11 @@ sax@^1.2.4:
   version "5.5.0"
   resolved "https://registry.yarnpkg.com/semver/-/semver-5.5.0.tgz#dc4bbc7a6ca9d916dee5d43516f0092b58f7b8ab"
 
+semver@^5.6.0:
+  version "5.6.0"
+  resolved "https://registry.yarnpkg.com/semver/-/semver-5.6.0.tgz#7e74256fbaa49c75aa7c7a205cc22799cac80004"
+  integrity sha512-RS9R6R35NYgQn++fkDWaOmqGoj4Ek9gGs+DPxNUZKuwE183xjJroKvyo1IzVFeXvUrvmALy6FWD5xrdJT25gMg==
+
 set-blocking@^2.0.0, set-blocking@~2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/set-blocking/-/set-blocking-2.0.0.tgz#045f9782d011ae9a6803ddd382b24392b3d890f7"

src/util/generate-pnp-map-api.tpl.js

@@ -647,11 +647,47 @@ exports.setup = function setup() {
       return originalModuleResolveFilename.call(Module, request, parent, isMain, options);
     }
 
-    const issuerModule = getIssuerModule(parent);
-    const issuer = issuerModule ? issuerModule.filename : process.cwd() + '/';
+    let issuers;
 
-    const resolution = exports.resolveRequest(request, issuer);
-    return resolution !== null ? resolution : request;
+    if (options) {
+      const optionNames = new Set(Object.keys(options));
+      optionNames.delete('paths');
+
+      if (optionNames.size > 0) {
+        throw makeError(
+          `UNSUPPORTED`,
+          `Some options passed to require() aren't supported by PnP yet (${Array.from(optionNames).join(', ')})`,
+        );
+      }
+
+      if (options.paths) {
+        issuers = options.paths.map(entry => `${path.normalize(entry)}/`);
+      }
+    }
+
+    if (!issuers) {
+      const issuerModule = getIssuerModule(parent);
+      const issuer = issuerModule ? issuerModule.filename : `${process.cwd()}/`;
+
+      issuers = [issuer];
+    }
+
+    let firstError;
+
+    for (const issuer of issuers) {
+      let resolution;
+
+      try {
+        resolution = exports.resolveRequest(request, issuer);
+      } catch (error) {
+        firstError = firstError || error;
+        continue;
+      }
+
+      return resolution !== null ? resolution : request;
+    }
+
+    throw firstError;
   };
 
   const originalFindPath = Module._findPath;