Add test for navigation

Update mocha and should

package.json

@@ -36,8 +36,8 @@
         "escape-string-regexp": "1.0.3"
     },
     "devDependencies": {
-        "mocha": "2.2.1",
-        "should": "5.2.0",
+        "mocha": "2.3.2",
+        "should": "7.1.0",
         "grunt": "~0.4.2",
         "grunt-cli": "0.1.11",
         "grunt-contrib-copy": "0.5.0",

test/json.js

@@ -35,7 +35,7 @@ describe('JSON generator', function () {
             it('should contains valid section', function() {
                 page.should.have.property("sections").with.lengthOf(1);
                 page.sections[0].should.have.property("content").which.is.a.String;
-                page.sections[0].should.have.property("type").which.is.a.String.which.equal("normal");
+                page.sections[0].should.have.property("type", "normal");
             });
 
             it('should contains valid progress', function() {

test/navigation.js

@@ -0,0 +1,61 @@
+var should = require('should');
+
+describe('Navigation', function () {
+    var book;
+
+    before(function() {
+        return books.parse("summary")
+            .then(function(_book) {
+                book = _book;
+            });
+    });
+
+    it('should correctly parse navigation as a map', function() {
+        book.should.have.property("navigation");
+        book.navigation.should.have.property("README.md");
+        book.navigation.should.have.property("README.md");
+    });
+
+    it('should correctly include filenames', function() {
+        book.navigation.should.have.property("README.md");
+        book.navigation.should.have.property("PAGE1.md");
+        book.navigation.should.have.property("folder/PAGE2.md");
+        book.navigation.should.not.have.property("NOTFOUND.md");
+    });
+
+    it('should correctly detect next/prev for README', function() {
+        var README = book.navigation['README.md'];
+
+        README.index.should.equal(0);
+        README.should.have.property('next');
+        should(README.prev).not.be.ok();
+
+        README.next.should.have.property('path');
+        README.next.path.should.equal('PAGE1.md');
+    });
+
+    it('should correctly detect next/prev a page', function() {
+        var PAGE = book.navigation['PAGE1.md'];
+
+        PAGE.index.should.equal(1);
+        PAGE.should.have.property('next');
+        PAGE.should.have.property('prev');
+
+        PAGE.prev.should.have.property('path');
+        PAGE.prev.path.should.equal('README.md');
+
+        PAGE.next.should.have.property('path');
+        PAGE.next.path.should.equal('folder/PAGE2.md');
+    });
+
+    it('should correctly detect next/prev for last page', function() {
+        var PAGE = book.navigation['folder/PAGE2.md'];
+
+        PAGE.index.should.equal(2);
+        PAGE.should.have.property('prev');
+        should(PAGE.next).not.be.ok();
+
+        PAGE.prev.should.have.property('path');
+        PAGE.prev.path.should.equal('PAGE1.md');
+    });
+});