What is the CDD EiffelStudio?

Cdd logo.png

Play CDD Video, click here

CDD (short for Contract Driven Development) is a project developed at ETH Zurich. It adds advanced support for unit testing to EiffelStudio. With CDD EiffelStudio you can

  • Write test cases
  • Manage test cases (using tags)
  • Run test cases
  • View test outcomes
  • Automatically extract test cases

If you have questions, feedback, or would like to report a bug please visit the CDD forum.

CDD EiffelStudio adds the following panel to regular EiffelStudio:

Cdd panel.png


Leitner, A., Ciupa, I., Oriol, M., Meyer, B., Fiva, A., "Contract Driven Development = Test Driven Development - Writing Test Cases", in Proceedings of ESEC/FSE'07: European Software Engineering Conference and the ACM SIGSOFT Symposium on the Foundations of Software Engineering 2007, (Dubrovnik, Croatia), September 2007 pdf bibtex

Leitner, A., Pretschner A., Mori S., Meyer B., Oriol M., "On the Effectiveness of Test Extraction without Overhead", under submission


14.May 2008: Added patch for Windows and Linux that fixes a bug that can cause a crash during extraction.

10.April 2008: If installation exits with cryptic error codes, please have a look at the Common Problems page.

08.April 2008: CDD EiffelStudio final 7 available

  • Important bug fix: EiffelStudio no longer freezes when opening projects with many test cases

02.April 2008: CDD EiffelStudio Final 6 available

  • Less mess: Redundant or duplicate test cases are no longer extracted
  • Smoother upgrade: Cleaning a project will automatically clean the test suite
  • Fixed bug in invarant checking
  • Fixed bug that caused EiffelStudio to freeze in some situations
  • Improved logging
  • Installer might work with mingw on Windows now. (Not yet tested, reports welcome)

Download CDD

The following packages contain the full EiffelStudio 6.1 plus the CDD extension. You do not need to have EiffelStudio installed already in order to install below packages. On Windows you do have to have either the Platform SDK or Visual C++ installed. Do not use EiffelStudio with the gcc/mingw or the .Net backend.



  • If you are upgrading from a previous version, make sure you delete the old version first (rm -rf)

Download the above file and install it just like you would install a EiffelStudio tar ball. Afterwards proceed to section "Using CDD". Make sure you set/update the environment variables PATH, ISE_EIFFEL, and ISE_PLATFORM according to the installation instructions.

Linux Patch

  • Patch for CDD EiffelStudio Final 7: Download and replace it with the '$ISE_EIFFEL/studio/spec/linux-x86/bin/ec' from Final 7. This patch fixes a crash that sometimes occurs during extraction of test cases. You may need to delete the precompile and EIFGENs of your project after applying the patch.



  • Installation is independent of installations of official EiffelStudio 6.1 (neither overwrites nor invalidates nor is influenced by those)
  • If you are upgrading from a previous version, you first have to uninstall the old version then delete the existing precompilations (= delete EIFGENs in subdirectories of <INSTALL_DIRECTORY>/precomp/spec/windows/) and then install the new version.
  • Which C compiler to install?
    • Use the Microsoft C compiler either from Visual Studio or the Windows SDK:
      • Visual Studio (up to Visual Studio 2005, but no later, and only the non-express version)
      • Windows SDK (up to version 6.0, but no later)
    • Do not use the gcc/mingw.
    • Do not use the .NET compiler backend.

Have a look at to learn how to install either Visual C++ or the Windows SDK for use with EiffelStudio.

Windows Patch

  • Patch for CDD EiffelStudio Final 7: Download and replace it with the '$ISE_EIFFEL/studio/spec/windows/bin/ec.exe' from Final 7. This patch fixes a crash that sometimes occurs during extraction of test cases. You may need to delete the precompile and EIFGENs of your project after applying the patch.


Manually Written Test Cases

CDD Eiffelstudio allows you to create a new “empty” test case. These test cases are similar to jUnit test cases. A manually written test class must start with the word “TEST” and all test routines also have to start with the word “test”. It also has to inherit from class CDD_TEST_CASE.

Extracted Test Cases

CDD EiffelStudio automatically extracts test cases whenever you run your program and an exception is triggered. This feature is novel and not yet part of any other testing environment. You will be the first to try it out.

Test outcomes

A test case checks whether your program contains a particular bug. A test cases can fail indicating that the bug is present in your program, or pass indicating your program does not contain this bug. Sometimes test cases will be unresolved, in which case the testing framework was unable to find out whether the test case passed or failed. A test case can be unresolved for several reasons.

Cdd buttons.png

Debug Test Case

Select a test case and press this button to run a test case in the debugger.

Enable/Disable Execution of Test Cases in Background

If enabled, all test cases are retested every time you press compile. If disabled no test cases are executed.

Enable/Disable automatic extraction of Test Cases

If enabled every time an exception is triggered a set of test cases that try to reproduce this exception is extracted. If disabled no test cases are extracted.

Clean up/Delete

You can use the “Clean Up/Delete” button in two different ways. By simply pressing it you will delete all unresolved test cases. By pick and dropping a test case to the “Clean up/Delete” button (right click on test case, move mouse to button and right click again) you can delete a test case. By the way, test cases are just regular classes. So you can use all existing tools that apply to classes in EiffelStudio too.

Update: To remove duplicate test cases (until the next cdd update), please use the command-line tool from the clean-cdd project.

Create new manual test class

Press this button to create a empty test class. You can then edit the class to add manually written test cases. This is how a manually written test case can look like:

      ba: BANK_ACCOUNT
      create ba.make_with_balance (0)
      ba.deposit (100)
         money_depisited: ba.balance = 100

Redefine routine `set_up' or `tear_down' if you want something to be executed before resp. after every test routine of a class.

Cdd buttons 2.png

Search for tags

Enter keywords to search for paritcular test cases. Some tags are automatically set for you like the name of the test case. You can also easily add your own tags by adding an indexing item "tag" to your test class or routine:

  tag: "fixme"

Tags can be adde to all test routines and classes. Whether they are extracted or manually written does not matter.

Restrict execution of test cases

Once you have many test cases, you will run into situation where you don't want to execute all of them. The restrict button will help you to achieve this. As long as the "Restrict" button is pushed test cases that don't show up in the test case view will not be tested. Execution is restricted to those test cases that do show up.

Change test case view

Select one of several predefined test case views. For example you can group test cases by their outcome to quickly see only failing test cases.

Further Documentation and Common Problems

Please visit Using CDD for further documentation or look at Common Problems if you run into problems.

Related Publications

  • Sunghun Kim, Shay Artzi, and Michael D. Ernst, "reCrash: Making Crash Reproducible" MIT Computer Science and Artificial Intelligence Laboratory technical report MIT-CSAIL-TR-2007-054, (Cambridge, MA), November 20, 2007. (pdf)

Project Internal Stuff