Support 'packagejson' as a custom cwd option.

README.md

@@ -52,6 +52,7 @@ Specify the plugin in your `.babelrc` with the custom root or alias. Here's an e
 - `extensions`: Array of extensions used in the resolver. Override the default extensions (`['.js', '.jsx', '.es', '.es6']`).
 - `cwd`: By default, the working directory is the one used for the resolver, but you can override it for your project.
     - The custom value `babelrc` will make the plugin look for the closest babelrc configuration based on the file to parse.
+    - The custom value `packagejson` will make the plugin look for the closest `package.json` based on the file to parse.
 
 ### Regular expression alias
 

package.json

@@ -32,6 +32,7 @@
   "dependencies": {
     "find-babel-config": "^1.0.1",
     "glob": "^7.1.1",
+    "pkg-up": "^1.0.0",
     "resolve": "^1.3.2"
   },
   "devDependencies": {

src/index.js

@@ -2,7 +2,6 @@ import normalizeOptions from './normalizeOptions';
 import transformCall from './transformers/call';
 import transformImport from './transformers/import';
 
-
 const importVisitors = {
   CallExpression: transformCall,
   'ImportDeclaration|ExportDeclaration': transformImport,

src/normalizeOptions.js

@@ -3,7 +3,7 @@ import path from 'path';
 
 import findBabelConfig from 'find-babel-config';
 import glob from 'glob';
-
+import pkgUp from 'pkg-up';
 
 const defaultExtensions = ['.js', '.jsx', '.es', '.es6'];
 
@@ -22,8 +22,17 @@ function normalizeCwd(opts, file) {
     opts.cwd = babelPath
       ? path.dirname(babelPath)
       : null;
-  }
+  } else if (opts.cwd === 'packagejson') {
+    const startPath = (file.opts.filename === 'unknown')
+      ? './'
+      : file.opts.filename;
+
+    const pkgPath = pkgUp.sync(startPath);
 
+    opts.cwd = pkgPath
+      ? path.dirname(pkgPath)
+      : null;
+  }
   if (!opts.cwd) {
     opts.cwd = process.cwd();
   }

test/index.test.js

@@ -597,4 +597,95 @@ describe('module-resolver', () => {
       });
     });
   });
+
+  describe('packagejson', () => {
+    const transformerOpts = {
+      babelrc: false,
+      plugins: [
+        [plugin, {
+          root: './src',
+          alias: {
+            test: './test',
+          },
+          cwd: 'packagejson',
+        }],
+      ],
+      filename: './test/testproject/src/app.js',
+    };
+
+    it('should resolve the sub file path', () => {
+      testWithImport(
+        'components/Root',
+        './components/Root',
+        transformerOpts,
+      );
+    });
+
+    it('should alias the sub file path', () => {
+      testWithImport(
+        'test/tools',
+        '../test/tools',
+        transformerOpts,
+      );
+    });
+
+    describe('unknown filename', () => {
+      const unknownFileTransformerOpts = {
+        babelrc: false,
+        plugins: [
+          [plugin, {
+            root: './src',
+            cwd: 'packagejson',
+          }],
+        ],
+      };
+      const cachedCwd = process.cwd();
+      const pkgJsonDir = 'test/testproject';
+
+      beforeEach(() => {
+        process.chdir(pkgJsonDir);
+      });
+
+      afterEach(() => {
+        process.chdir(cachedCwd);
+      });
+
+      it('should resolve the sub file path', () => {
+        testWithImport(
+          'components/Root',
+          './src/components/Root',
+          unknownFileTransformerOpts,
+        );
+      });
+    });
+
+    describe('missing packagejson in path (uses cwd)', () => {
+      jest.mock('pkg-up', () => ({
+        sync: function pkgUpSync() {
+          return null;
+        },
+      }));
+      jest.resetModules();
+      const pluginWithMock = require.requireActual('../src').default;
+
+      const missingPkgJsonConfigTransformerOpts = {
+        babelrc: false,
+        plugins: [
+          [pluginWithMock, {
+            root: '.',
+            cwd: 'packagejson',
+          }],
+        ],
+        filename: './test/testproject/src/app.js',
+      };
+
+      it('should resolve the sub file path', () => {
+        testWithImport(
+          'test/testproject/src/components/Root',
+          './components/Root',
+          missingPkgJsonConfigTransformerOpts,
+        );
+      });
+    });
+  });
 });

test/testproject/package.json

@@ -0,0 +1 @@
+{}