fix(UrlMatcherFactory): Correct trailing slash of terminal optional p…

…arameter

Fixes #1902

src/urlMatcherFactory.js

@@ -342,6 +342,8 @@ UrlMatcher.prototype.format = function (values) {
 
     if (isPathParam) {
       var nextSegment = segments[i + 1];
+      var isFinalPathParam = i + 1 === nPath;
+
       if (squash === false) {
         if (encoded != null) {
           if (isArray(encoded)) {
@@ -357,6 +359,8 @@ UrlMatcher.prototype.format = function (values) {
       } else if (isString(squash)) {
         result += squash + nextSegment;
       }
+
+      if (isFinalPathParam && param.squash === true && result.slice(-1) === '/') result = result.slice(0, -1);
     } else {
       if (encoded == null || (isDefaultValue && squash !== false)) continue;
       if (!isArray(encoded)) encoded = [ encoded ];

test/urlMatcherFactorySpec.js

@@ -149,6 +149,14 @@ describe("UrlMatcher", function () {
           params = { id: 'bob', section: 'contact-details' };
       expect(m.format(params)).toEqual('/users/bob#contact-details');
     });
+
+    it("should trim trailing slashes when the terminal value is optional", function () {
+      var config = { params: { id: { squash: true, value: '123' } } },
+          m = new UrlMatcher('/users/:id', config),
+          params = { id: '123' };
+
+      expect(m.format(params)).toEqual('/users');
+    });
   });
 
   describe(".concat()", function() {
@@ -623,8 +631,8 @@ describe("urlMatcherFactory", function () {
         params: { id: { value: null, squash: true }, state: { value: null, squash: true } }
       });
 
-      expect(m.format()).toBe("/users/");
-      expect(m.format({ id: 1138 })).toBe("/users/1138/");
+      expect(m.format()).toBe("/users");
+      expect(m.format({ id: 1138 })).toBe("/users/1138");
       expect(m.format({ state: "NY" })).toBe("/users/NY");
       expect(m.format({ id: 1138, state: "NY" })).toBe("/users/1138/NY");
     });