fix(groupRoutes): simplify .groupRoutes method

README.md

@@ -321,7 +321,7 @@ app.listen(2222, () => {
 })
 ```
 
-### [.middleware](index.js#L479)
+### [.middleware](index.js#L474)
 > Active all routes that are defined. You can pass `opts` to pass different `prefix` for your routes. So you can have multiple prefixes with multiple routes using just one single router. You can also use multiple router instances. Pass `legacy: true` to `opts` and you will get generator function that can be used in Koa v1.
 
 **Params**
@@ -367,7 +367,7 @@ app.listen(4321, () => {
 })
 ```
 
-### [.legacyMiddleware](index.js#L559)
+### [.legacyMiddleware](index.js#L554)
 > Converts the modern middleware routes to generator functions using [koa-convert][].back under the hood. It is sugar for the `.middleware(true)` or `.middleware({ legacy: true })`
 
 * `returns` **{Function|GeneratorFunction}**  

index.js

@@ -415,12 +415,7 @@ KoaBetterRouter.prototype.groupRoutes = function groupRoutes (dest, src1, src2)
   let pathname = dest.route + src1.route
   let route = this.createRoute(dest.method, pathname, src1.middlewares)
 
-  if (utils.isObject(src2)) {
-    pathname = route.route + src2.route
-    route = this.createRoute(dest.method, pathname, src2.middlewares)
-  }
-
-  return route
+  return utils.isObject(src2) ? this.groupRoutes(route, src2) : route
 }
 
 /**

package.json

@@ -13,7 +13,7 @@
     "test": "npm run coverage",
     "posttest": "npm run lint:coverage",
     "coverage": "nyc node test.js",
-    "lint:coverage": "nyc check-coverage --lines 100 --branches 95 --statements 100 --functions 100",
+    "lint:coverage": "nyc check-coverage --lines 100 --branches 97 --statements 100 --functions 100",
     "report-coverage": "nyc report --reporter=text-lcov | coveralls",
     "prerelease": "npm test",
     "release": "standard-version --sign --no-verify",

utils.js

@@ -21,7 +21,7 @@ utils.typeOf = function typeOf (val) {
 }
 
 utils.isObject = function isObject (val) {
-  return utils.typeOf(val) === 'object'
+  return val && utils.typeOf(val) === 'object'
 }
 
 utils.arrayify = function arrayify (val) {