Correct bug in Registry#findBy, add spec

lib/registry.js

@@ -68,7 +68,7 @@ var Registry = module.exports = {
 
   findBy: function(prop, name) {
     // pluralize, if necessary
-    if (!/s$/.test(name)) {
+    if (prop.slice(-1) !== "s") {
       prop += "s";
     }
 
@@ -102,7 +102,7 @@ var Registry = module.exports = {
     for (var name in this.data) {
       var repo = this.data[name];
 
-      if (~repo[entry].indexOf(value)) {
+      if (repo[entry] && ~repo[entry].indexOf(value)) {
         return repo.module;
       }
     }

spec/lib/registry.spec.js

@@ -52,4 +52,22 @@ describe("Registry", function() {
       });
     });
   });
+
+  describe("#findBy", function() {
+    beforeEach(function() {
+      stub(Registry, "search");
+    });
+
+    afterEach(function() {
+      Registry.search.restore();
+    });
+
+    it("calls #search, pluralizing if necessary", function() {
+      Registry.findBy("adaptors", "testing");
+      expect(Registry.search).to.be.calledWith("adaptors", "testing");
+
+      Registry.findBy("driver", "testing");
+      expect(Registry.search).to.be.calledWith("drivers", "testing");
+    });
+  });
 });