packager: add support for relative files with custom extensions

Reviewed By: cpojer

Differential Revision: D4994139

fbshipit-source-id: 5e47c5bc6f8b2cd750f1ca0df940c23234c66600

packager/src/ModuleGraph/node-haste/node-haste.js

@@ -34,6 +34,7 @@ const defaults = require('../../../defaults');
 type ResolveOptions = {|
   assetExts: Extensions,
   extraNodeModules: {[id: string]: string},
+  +sourceExts: Extensions,
   transformedFiles: {[path: Path]: TransformedCodeFile},
 |};
 
@@ -72,6 +73,7 @@ exports.createResolveFn = function(options: ResolveOptions): ResolveFn {
     assetExts,
     extraNodeModules,
     transformedFiles,
+    sourceExts,
   } = options;
   const files = Object.keys(transformedFiles);
   function getTransformedFile(path) {
@@ -93,7 +95,7 @@ exports.createResolveFn = function(options: ResolveOptions): ResolveFn {
     getTransformedFile,
   );
   const hasteMap = new HasteMap({
-    extensions: ['js', 'json'],
+    extensions: sourceExts,
     files,
     helpers,
     moduleCache,
@@ -119,6 +121,7 @@ exports.createResolveFn = function(options: ResolveOptions): ResolveFn {
         platform,
         platforms,
         preferNativePlatform: true,
+        sourceExts,
       });
     }