Add logic for alternate node module directory resolution

packages/cli-tools/src/__tests__/resolveNodeModuleDir.test.ts

@@ -0,0 +1,50 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ */
+
+import resolveNodeModuleDir, {
+  alternateResolveNodeModuleDir,
+} from '../resolveNodeModuleDir';
+
+import packageJson from '../../package.json';
+
+describe('alternateResolveNodeModulesDir', () => {
+  it('should be identical to default resolution for this projects dependencies', () => {
+    const packages = [
+      ...Object.keys(packageJson.dependencies),
+      ...Object.keys(packageJson.devDependencies),
+    ].filter((a) => !a.match('@react-native-community') && !a.match('@types'));
+
+    packages.forEach((pkg) => {
+      const dir = resolveNodeModuleDir(__dirname, pkg);
+      const alternateDir = alternateResolveNodeModuleDir(__dirname, pkg);
+      expect(dir).toEqual(alternateDir);
+    });
+  });
+
+  it('should return identical output for package deep file requires', () => {
+    const pkgs = [
+      'lodash/intersection.js',
+      'lodash/package.json',
+      'yargs/locales/en.json',
+    ];
+    pkgs.forEach((pkg) => {
+      const dir = resolveNodeModuleDir(__dirname, pkg);
+      const alternateDir = alternateResolveNodeModuleDir(__dirname, pkg);
+      expect(dir).toEqual(alternateDir);
+    });
+  });
+
+  it('should blow up for non-existent packages', () => {
+    const pkgs = ['blerbqwerzxcqwerv', 'qwerasdfasdfertrr/asdfasdf'];
+    pkgs.forEach((pkg) => {
+      expect(() => {
+        alternateResolveNodeModuleDir(__dirname, pkg);
+      }).toThrow();
+    });
+  });
+});

packages/cli-tools/src/resolveNodeModuleDir.ts

@@ -7,9 +7,43 @@ export default function resolveNodeModuleDir(
   root: string,
   packageName: string,
 ): string {
-  return path.dirname(
-    require.resolve(path.join(packageName, 'package.json'), {
-      paths: [root],
-    }),
-  );
+  try {
+    return path.dirname(
+      require.resolve(path.join(packageName, 'package.json'), {
+        paths: [root],
+      }),
+    );
+  } catch (e) {
+    //TODO: Remove this alternate method once Node figures out a better way of resolving the package root directory. See https://github.com/nodejs/loaders/issues/26
+    return alternateResolveNodeModuleDir(root, packageName);
+  }
+}
+
+export function alternateResolveNodeModuleDir(
+  root: string,
+  packageName: string,
+) {
+  const moduleMainFilePath = require.resolve(packageName, {paths: [root]});
+
+  const moduleNameParts = packageName.split('/');
+
+  let searchForPathSection;
+
+  if (packageName.startsWith('@') && moduleNameParts.length > 1) {
+    const [org, mod] = moduleNameParts;
+    searchForPathSection = `node_modules${path.sep}${org}${path.sep}${mod}`;
+  } else {
+    const [mod] = moduleNameParts;
+    searchForPathSection = `node_modules${path.sep}${mod}`;
+  }
+
+  const lastIndex = moduleMainFilePath.lastIndexOf(searchForPathSection);
+
+  if (lastIndex === -1) {
+    throw new Error(
+      `Unable to resolve base directory of package ${packageName}. Searched inside the resolved main file path "${moduleMainFilePath}" using "${searchForPathSection}"`,
+    );
+  }
+
+  return moduleMainFilePath.slice(0, lastIndex + searchForPathSection.length);
 }