Align our sync resolving behavior with async (#90)

Since there was diverging behavior between the two codepaths, our async
path would properly resolve shimmed relative path files without extensions, however our
sync path would not.

Additionally Normalize the path to empty.js correctly on windows.

Fixes #89

Author: dcherman

index.js

@@ -53,7 +53,7 @@ function find_shims_in_package(pkgJson, cur_path, shims, browser) {
     Object.keys(replacements).forEach(function(key) {
         var val;
         if (replacements[key] === false) {
-            val = __dirname + '/empty.js';
+            val = path.normalize(__dirname + '/empty.js');
         }
         else {
             val = replacements[key];
@@ -299,15 +299,17 @@ resolve.sync = function (id, opts) {
 
     // we must always load shims because the browser field could shim out a module
     var shims = load_shims_sync(paths, opts.browser);
+    var resid = path.resolve(opts.basedir || path.dirname(opts.filename), id);
 
-    if (shims[id]) {
+    if (shims[id] || shims[resid]) {
+        var xid = shims[id] ? id : resid;
         // if the shim was is an absolute path, it was fully resolved
-        if (shims[id][0] === '/') {
-            return shims[id];
+        if (shims[xid][0] === '/') {
+            return resv.sync(shims[xid], build_resolve_opts(opts, base));
         }
 
         // module -> alt-module shims
-        id = shims[id];
+        id = shims[xid];
     }
 
     var modules = opts.modules || Object.create(null);

test/fixtures/node_modules/module-t/package.json

@@ -73,6 +73,17 @@ test('test foobar -> module-b replacement', function() {
     assert.equal(path, require.resolve('./fixtures/node_modules/module-b/main'));
 });
 
+// browser field in package.json maps "relative file" -> "relative file" with no extension
+test('test ./x -> ./y replacement', function() {
+    var parent = {
+        filename: fixtures_dir + '/module-t/index.js',
+        package: { main: './index.js' }
+    };
+
+    var path = resolve.sync('./x', parent);
+    assert.equal(path, require.resolve('./fixtures/node_modules/module-t/y.js'));
+});
+
 // same as above but replacing core
 test('test core -> module-c replacement', function() {
     var parent = {

test/fixtures/node_modules/module-t/x.js

@@ -194,6 +194,20 @@ test('test foobar -> module-b replacement with transform', function(done) {
     });
 });
 
+// browser field in package.json maps "relative file" -> "relative file" with no extension
+test('test ./x -> ./y replacement', function(done) {
+    var parent = {
+        filename: fixtures_dir + '/module-t/index.js',
+        package: { main: './index.js' }
+    };
+
+    resolve('./x', parent, function(err, path, pkg) {
+        assert.ifError(err);
+        assert.equal(path, require.resolve('./fixtures/node_modules/module-t/y.js'));
+        done();
+    });
+});
+
 test('test foobar -> module-i replacement with transform in replacement', function(done) {
     var parent = {
         filename: fixtures_dir + '/module-j/index.js',