follow symlinks

src/utils/defaults.js

@@ -1,4 +1,4 @@
-import { isFile, readFileSync } from './fs.js';
+import { lstatSync, readFileSync, realpathSync } from './fs.js';
 import { dirname, isAbsolute, resolve } from './path.js';
 import { blank } from './object.js';
 
@@ -6,15 +6,22 @@ export function load ( id ) {
 	return readFileSync( id, 'utf-8' );
 }
 
-function addJsExtensionIfNecessary ( file ) {
-	if ( isFile( file ) ) return file;
-
-	file += '.js';
-	if ( isFile( file ) ) return file;
+function findFile ( file ) {
+	try {
+		const stats = lstatSync( file );
+		if ( stats.isSymbolicLink() ) return findFile( realpathSync( file ) );
+		if ( stats.isFile() ) return file;
+	} catch ( err ) {
+		// suppress
+	}
 
 	return null;
 }
 
+function addJsExtensionIfNecessary ( file ) {
+	return findFile( file ) || findFile( file + '.js' );
+}
+
 export function resolveId ( importee, importer ) {
 	// absolute paths are left untouched
 	if ( isAbsolute( importee ) ) return addJsExtensionIfNecessary( importee );

src/utils/fs.js

@@ -12,15 +12,6 @@ function mkdirpath ( path ) {
 	}
 }
 
-export function isFile ( file ) {
-	try {
-		const stats = fs.statSync( file );
-		return stats.isFile();
-	} catch ( err ) {
-		return false;
-	}
-}
-
 export function writeFile ( dest, data ) {
 	return new Promise( ( fulfil, reject ) => {
 		mkdirpath( dest );
@@ -35,5 +26,7 @@ export function writeFile ( dest, data ) {
 	});
 }
 
+export const lstatSync = fs.lstatSync;
 export const readdirSync = fs.readdirSync;
 export const readFileSync = fs.readFileSync;
+export const realpathSync = fs.realpathSync;

test/function/symlink/_config.js

@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'follows symlinks'
+};

test/function/symlink/foo.js

@@ -0,0 +1 @@
+symlinked/bar.js

test/function/symlink/main.js

@@ -0,0 +1,2 @@
+import foo from './foo.js';
+assert.equal( foo, 'BAZ' );

test/function/symlink/symlinked/bar.js

@@ -0,0 +1,2 @@
+import baz from './baz.js';
+export default baz();

test/function/symlink/symlinked/baz.js

@@ -0,0 +1,3 @@
+export default function () {
+	return 'BAZ';
+}