@@ -12,28 +12,16 @@ function mostSpecificRouteMatch(match1, match2) {

   const paramLength1 = match1.routeParams.length;

   const paramLength2 = match2.routeParams.length;

+  let findWildcard = R.compose(R.findIndex.bind(R, isWildcard), pathSplit)

-  let result = null;

+  let result = (paramLength1 > paramLength2) ? match2 : match1;

   if (paramLength1 === paramLength2) {

-    let path1Parts = pathSplit(match1.path);

-    let path2Parts = pathSplit(match2.path);

-

-    for (let [segment1, segment2] of R.zip(path1Parts, path2Parts)) {

-      if (isWildcard(segment1)) {

-        result = match2;

-      } else if (isWildcard(segment2)) {

-        result = match1;

-      }

-      if (result !== null) {

-        break;

-      }

-    }

-  } else if (paramLength1 > paramLength2) {

-    result = match2;

-  } else if (paramLength2 > paramLength1) {

-    result = match1;

+    let path1WildcardIdx = findWildcard(match1.path);

+    let path2WildcardIdx = findWildcard(match2.path);

+

+    result = (path1WildcardIdx !== -1 && path1WildcardIdx < path2WildcardIdx) ? match2 : match1;

   }

   if (result === null) {

@@ -210,6 +198,35 @@ function getRouteByPath(pattern, matchers) {

   return matchers.compiledRouteMatchers[pattern];

 }

+function normalizeWildcards(path) {

+  let curIdx = 0;

+  return path.map((el) => {

+    if (isWildcard(el)) {

+      return `:wildcard${curIdx}`

+    } else {

+      return el;

+    }

+  });

+}

+

+function routeAlreadyExists(compiledRouteMatchers, path) {

+  let result = compiledRouteMatchers.hasOwnProperty(path)

+

+  if (!result) {

+    const normalizingSplit = R.compose(normalizeWildcards, pathSplit);

+    const pathParts = normalizingSplit(path);

+

+    for (const otherPath of Object.keys(compiledRouteMatchers)) {

+      const otherPathParts = normalizingSplit(otherPath);

+      if (R.equals(pathParts, otherPathParts)) {

+        throw new Error(`invalid routing configuration — route ${path} overlaps with route ${otherPath}`)

+      }

+    }

+  }

+

+  return result;

+}

+

 function compileRoutes(routesConfig) {

   let compiledActionMatchers = {};

   let compiledRouteMatchers = {};

@@ -227,7 +244,7 @@ function compileRoutes(routesConfig) {

     const route = makeRoute(path, action, extraParams);

     compiledActionMatchers[action].push(route);

-    if (compiledRouteMatchers.hasOwnProperty(path)) {

+    if (routeAlreadyExists(compiledRouteMatchers, path)) {

       throw new Error("overlapping paths");

     }

@@ -188,19 +188,44 @@ it("router should match non-wildcard route in preference to wildcard route", ()

   expect(actionsDispatched()).toEqual([{type: 'ACTION_NAME', id: 1}]);

 });

+it("router should throw on duplicate paths", () => {

+  // given

+  const routesConfig = [

+    ['/somewhere/:id', 'ACTION_NAME', {}],

+    ["/somewhere/:id", 'ACTION_NAME', {}],

+  ];

+

+  expect( () => {

+    setupTest(routesConfig);

+  }).toThrow();

+});

+

+it("router should throw on equally specific routes", () => {

+  // given

+  const routesConfig = [

+    ['/somewhere/:id', 'ACTION_NAME', {}],

+    ["/somewhere/:specific", 'ACTION_NAME', {}],

+  ];

+

+  expect( () => {

+    const {actionsDispatched, fireUrlChange} = setupTest(routesConfig);

+    fireUrlChange('/somewhere/specific');

+  }).toThrow();

+});

+

 it("router should match less-wildcarded routes in preference to more wildcarded routes", () => {

   //given

   const routesConfig = [

-    ["/somewhere/specific/:view", "ACTION_NAME", {id: 1}],

-    ["/somewhere/:id/:view", "ACTION_NAME", {}],

+    ["/somewhere/:id/:view/:bar", "ACTION_NAME", {}],

+    ["/somewhere/:foo/:id/:view/:baz", "ACTION_NAME", {}],

   ];

   const {actionsDispatched, fireUrlChange} = setupTest(routesConfig);

   // when

-  fireUrlChange('/somewhere/specific/etc');

+  fireUrlChange('/somewhere/specific/etc/bar');

   // then

-  expect(actionsDispatched()).toEqual([{type:'ACTION_NAME', id: 1, view: "etc"}]);

+  expect(actionsDispatched()).toEqual([{type:'ACTION_NAME', id: "specific", view: "etc", bar: "bar"}]);

 });