Cornipickle: a runtime monitor for layout constraints

Cornipickle is an automated testing tool that can verify declarative properties on-the-fly as a user interacts with an application. Test oracles are written in a a declarative language that can express desirable properties of a web application as a set of human-readable assertions on the page's HTML and CSS data.

Table of Contents {#toc}

• Compiling and installing Cornipickle
• Command-line usage
• Using Cornipickle on your server
• Status page
• Further documentation
• About the authors

Compiling and Installing Cornipickle {#install}

With Docker

First make sure you have a docker installed.

Build:

docker build . --tag cornipickle

Run

docker run -it -p10101:10101 cornipickle

Without Docker

First make sure you have the following installed:

To use Cornipickle, the easiest way is to download a pre-compiled release from the Releases page.

If you want to build Cornipickle by yourself, first make sure you have the following installed:

• The Java Development Kit (JDK) to compile. Cornipickle was developed and tested on version 6 of the JDK, but it is probably safe to use any later version.
• Ant to automate the compilation and build process

Download the sources for Cornipickle from GitHub or clone the repository using Git:

git@github.com:liflab/cornipickle.git

Installing dependencies

The project requires the following libraries to be present in the system:

• The json-lif library for fast JSON parsing (tested with version 1.6.3)
• The Azrael library for serialization of Java objects. (tested with version 0.7.3-alpha)
• The Bullwinkle parser, an on-the-fly parser for BNF grammars. (tested with version 1.4.2)
• The Jerrydog server for basic HTTP server capabilities. (tested with version 0.3.1-alpha)

Using Ant, you can automatically download any libraries missing from your system by typing:

ant download-deps

This will put the missing JAR files in the dep folder in the project's Server folder.

Compiling

Compile the sources by simply typing:

ant

This will produce a file called cornipickle.jar in the folder. This file is runnable and stand-alone, or can be used as a library, so it can be moved around to the location of your choice.

In addition, the script generates in the doc folder the Javadoc documentation for using Cornipickle.

Testing

Cornipickle can test itself by running:

ant test

Unit tests are run with jUnit; a detailed report of these tests in HTML format is availble in the folder tests/junit, which is automatically created. Code coverage is also computed with JaCoCo; a detailed report is available in the folder tests/coverage.

Command-line Usage {#cli}

Cornipickle works as a server. You start it on the command line with:

java -jar cornipickle.jar [options] [file1 [file2 ...]]

where file1, file2, etc. are optional filenames containing Cornipickle specifications that the server can pre-load. Available options are:

-h, --help : Display command line usage

-p,--port <x> : Listen on port x (default: 10101)

-s,--servername <x> : Set server name or IP address x (default: localhost)

--serve-as <path> : Serve local folder as remote folder . For example, with the default settings, when launching Cornipickle with --serve-as myfolder/ (note the trailing slash), the URL http://localhost:10101/myfolder/foo.bar will refer to foo.bar from the local folder where Cornipickle is launched. This also works for nested folders.

Using Cornipickle on your server {#server}

Cornipickle uses Ajax to relay information between the browser and its interpreter. If you want to use Cornipickle to test an application hosted on your server, you need to enable Cross-origin resource sharing (CORS) on the server that hosts your site.

Suppose that:

• your site is hosted on myserver.com, running on a server that listens to port 80;
• you wish to run the Cornipickle server on myserver.com, listening to port 10101 (it cannot be set to the same port as your web server).

Normally, as per the Same-Origin Policy (SOP), a page served from myserver.com:80 is forbidden to send an Ajax request to myserver.com:10101 --meaning that the web site will not be able to relay data to Cornipickle. To enable CORS on the server, please refer to this page: https://enable-cors.org/server.html. For example, on Apache, you must add the following line to the server's .htaccess configuration file:

Header set Access-Control-Allow-Origin "http://myserver.com:10101"

Built-in Examples

Cornipickle contains a few examples. Using the default settings, you can try these examples by starting the server and visiting http://localhost:10101/examples/index.html in your browser.

Status page {#status}

You can have more detailed status on the specifications that Cornipickle is watching through a simple web interface. Using the default settings, you can try these examples by starting the server and visiting http://localhost:10101/status in your browser. Refresh the page to get updated info.

Further documentation {#doc}

More online documentation about Cornipickle is under way. In the meantime, please refer to Cornipickle's page on the LIF's website for references to presentation slides and research papers detailing how the tool works and how to use the language.

Please feel free to contact us if you have any questions, or if you want to use Cornipickle in a specific context.

About the authors {#about}

Cornipickle was first written by Sylvain Hallé, associate professor at Université du Québec à Chicoutimi, Canada, and head of the Laboratoire d'informatique formelle. Special thanks to the team of of graduate and undergraduate students who contributed to the development of Cornipickle:

• Gabrielle Bastien
• Nicolas Bergeron
• Oussama Beroual
• Xavier Chamberland-Thibeault
• Francis Guérin
• Chafik Meniar
• Florence Opalvens
• Jérémy Spieldenner