add option to preserve trailing slash

Author: robbtraister

README.md

@@ -96,6 +96,7 @@ All CLI options are optional:
 --corsDisallowCredentials   When provided, the default Access-Control-Allow-Credentials header value will be passed as 'false'. Default: true
 --exec "<script>"           When provided, a shell script is executed when the server starts up, and the server will shut down after handling this command.
 --noAuth                    Turns off all authorizers
+--preserveTrailingSlash     Used to keep trailing slashes on the request path
 ```
 
 Any of the CLI options can be added to your `serverless.yml`. For example:

src/index.js

@@ -119,6 +119,9 @@ class Offline {
           },
           useSeparateProcesses: {
             usage: 'Uses separate node processes for handlers',
+          },
+          preserveTrailingSlash: {
+            usage: 'Used to keep trailing slashes on the request path'
           }
         },
       },
@@ -233,6 +236,7 @@ class Offline {
       corsAllowCredentials: true,
       apiKey: crypto.createHash('md5').digest('hex'),
       useSeparateProcesses: false,
+      preserveTrailingSlash: false
     };
 
     this.options = _.merge({}, defaultOpts, (this.service.custom || {})['serverless-offline'], this.options);
@@ -286,7 +290,7 @@ class Offline {
     this.server = new Hapi.Server({
       connections: {
         router: {
-          stripTrailingSlash: true, // removes trailing slashes on incoming paths.
+          stripTrailingSlash: !this.option.preserveTrailingSlash, // removes trailing slashes on incoming paths.
         },
       },
     });