Fall back on bad locale objects

fixes #6

index.js

@@ -47,10 +47,8 @@ var proto = {
      * @returns {*}
      */
     resolve: function (name, locale) {
-        var match, loc;
-        name = name + this._ext;
-        loc = locale ? util.parseLangTag(locale) : this._fallback;
-        match = this._locate(name, loc);
+        var loc = util.selectLangTag(locale, this._fallback);
+        var match = this._locate(name + this._ext, loc);
         return match;
     }
 

lib/util.js

@@ -27,7 +27,9 @@ var fs = require('graceful-fs'),
  * @param str String a language tag in the format `en-US`, `en_US`, `en`, etc.
  * @returns {{language: string, country: string}}
  */
-exports.parseLangTag = function (str) {
+exports.parseLangTag = parseLangTag;
+
+function parseLangTag(str) {
     var pair, tuple;
 
     if (typeof str === 'object') {
@@ -46,7 +48,7 @@ exports.parseLangTag = function (str) {
     }
 
     return pair;
-};
+}
 
 
 /**
@@ -79,3 +81,14 @@ exports.locate = function locate(name, root, start) {
     }
 
 };
+
+exports.selectLangTag = function selectLangTag(primary, fallback) {
+    primary = parseLangTag(primary);
+    fallback = parseLangTag(fallback);
+
+    if (primary.country && primary.language) {
+        return primary;
+    } else {
+        return fallback;
+    }
+};

test/index.js

@@ -110,4 +110,26 @@ test('fileResolver', function (t) {
         t.equal(typeof resolvr._locate, 'function');
         t.end();
     });
+
+    t.test('resolve with a bogus locale object', function (t) {
+        var resolvr = fileResolver.create({root: __dirname + '/fixtures/root', ext: 'dust'});
+        var info = resolvr.resolve('test', {});
+
+        t.equal(info.root, __dirname + '/fixtures/root/');
+        t.equal(info.file, __dirname + '/fixtures/root/test.dust');
+        t.equal(info.ext, 'dust');
+        t.equal(info.name, 'test');
+        t.end();
+    });
+
+    t.test('fall back with a bogus locale object', function (t) {
+        var resolvr = fileResolver.create({root: __dirname + '/fixtures/root', ext: 'dust', fallback: 'en_US'});
+        var info = resolvr.resolve('test', {});
+
+        t.equal(info.root, __dirname + '/fixtures/root/US/en/');
+        t.equal(info.file, __dirname + '/fixtures/root/US/en/test.dust');
+        t.equal(info.ext, 'dust');
+        t.equal(info.name, 'test');
+        t.end();
+    });
 });