Fix issue where regex is stripped during json stringify (#228)

JSON.stringify stringifys RegExp as an empty object literal. This fix post process the toolbox origin regex if one exists so we have it when code generating.

lib/sw-precache.js

@@ -104,13 +104,22 @@ function generateRuntimeCaching(runtimeCaching) {
         // include its body inline.
         (typeof curr.handler === 'string' ? 'toolbox.' : '') + curr.handler,
         // Default to no options.
-        JSON.stringify(curr.options || {}));
+        stringifyToolboxOptions(curr.options));
     }
 
     return prev + line;
   }, '');
 }
 
+function stringifyToolboxOptions(options) {
+  options = options || {};
+  var str = JSON.stringify(options);
+  if (options.origin instanceof RegExp) {
+    str = str.replace(/("origin":)\{\}/, '$1' + options.origin);
+  }
+  return str;
+}
+
 function generate(params, callback) {
   return new Promise(function(resolve, reject) {
     params = defaults(params || {}, {

test/test.js

@@ -445,4 +445,26 @@ describe('generateRuntimeCaching', function() {
     }]);
     assert.equal(code, '\ntoolbox.router.get(/test/, toolbox.testHandler, {});');
   });
+
+  it('should handle origin regex', function() {
+    var code = generateRuntimeCaching([{
+      urlPattern: '/*',
+      handler: 'testHandler',
+      options: {
+        origin: /http:\/\/www.example\.com/
+      }
+    }]);
+    assert.equal(code, '\ntoolbox.router.get("/*", toolbox.testHandler, {"origin":/http:\\/\\/www.example\\.com/});');
+  });
+
+  it('should handle origin string', function() {
+    var code = generateRuntimeCaching([{
+      urlPattern: '/*',
+      handler: 'testHandler',
+      options: {
+        origin: 'http://www.example.com'
+      }
+    }]);
+    assert.equal(code, '\ntoolbox.router.get("/*", toolbox.testHandler, {"origin":"http://www.example.com"});');
+  });
 });