Prevent double slash in the resource URLs

SwaggerUI builds resource URL by concatenating basePath + resourcePath.
Since the resource paths are always startign with a slash, if the
basePath ends with a slash too, an incorrect URL is produced.
This was typically happenning when `restApiRoot` was '/'.

This commit modifies the code producing the base path to remove
the trailing slash.

lib/swagger.js

@@ -156,6 +156,11 @@ function addRoute(app, uri, doc, opts) {
   var hasBasePath = Object.keys(doc).indexOf('basePath') !== -1;
   var initialPath = doc.basePath || '';
 
+  // Remove the trailing slash, see
+  // https://github.com/strongloop/loopback-explorer/issues/48
+  if (initialPath[initialPath.length-1] === '/')
+    initialPath = initialPath.slice(0, -1);
+
   app.get(urlJoin('/', uri), function(req, res) {
 
     // There's a few forces at play that require this "hack". The Swagger spec

test/explorer.test.js

@@ -4,6 +4,7 @@ var request = require('supertest');
 var assert = require('assert');
 var path = require('path');
 var expect = require('chai').expect;
+var urlJoin = require('../lib/url-join');
 
 describe('explorer', function() {
 
@@ -78,6 +79,26 @@ describe('explorer', function() {
           done();
         });
     });
+
+    it('removes trailing slash from baseUrl', function(done) {
+      // SwaggerUI builds resource URL by concatenating basePath + resourcePath
+      // Since the resource paths are always startign with a slash,
+      // if the basePath ends with a slash too, an incorrect URL is produced
+      var app = loopback();
+      app.set('restApiRoot', '/');
+      configureRestApiAndExplorer(app);
+
+      request(app)
+        .get('/explorer/resources/products')
+        .expect(200)
+        .end(function(err, res) {
+          if (err) return done(err);
+          var baseUrl = res.body.basePath;
+          var apiPath = res.body.apis[0].path;
+          expect(baseUrl + apiPath).to.match(/http:\/\/[^\/]+\/products/);
+          done();
+        });
+    });
   });
 
   describe('with custom front-end files', function() {
@@ -146,7 +167,7 @@ describe('explorer', function() {
   }
 
   function configureRestApiAndExplorer(app, explorerBase) {
-    var Product = loopback.Model.extend('product');
+    var Product = loopback.PersistedModel.extend('product');
     Product.attachTo(loopback.memory());
     app.model(Product);