t-unit: tcl unit test package

t-unit: Tcl Unit TestPackage

Automated Unit Test PackageFor Tcl ProceduresFinal Presentation

Joseph BoyleLoyola Marymount University

Loyola Marymount University 2

Introduction

Understand how Agile Software practices can be used in a scripting language environment

How Agile practices can be applied in an industry that is big on up-front design

Create a project that is open source

Final PresentationIntroductionUpdated: 25-Nov-2006


Related Work

Many key players in the Agile movement Kent Beck

Extreme Programming Martin Fowler

Refactoring, Continuous Integration Andrew Hunt and David Thomas

The Pragmatic Programmer

Tcl Scripting Language Created by John Ousterhout in early 1980’s at Berkeley

Final PresentationRelated WorkUpdated: 25-Nov-2006


State of Software Development

Need to get away from plan-driven approach Can’t see the complexity of the software ahead of

time The culture must be ready for change! Start with a vision and a set of principles that

defines what needs to be accomplished From these principles we can derive a set of

working practices

Final PresentationState of SW DevelopmentUpdated: 25-Nov-2006


Agile Culture

Disciplined in approach and goal focused Responsible for one’s work Leaders that can help others succeed Highly collaborative team that can embrace

differences between personalities and roles and strive for success

Feel comfortable communicating with the team Keep the product simple to solve only the problem

at hand Courage to speak up when things are going bad

Final PresentationAgile CultureUpdated: 25-Nov-2006


Agile Principles

Continual Refinement Enhances the ability to change with the customer’s needs

Working Product at All Times The goal of software developers is to ship software. Keep

the software as close as possible to a shipping state. Continual investment in and emphasis on Design

Design decisions and changes are made every day by every member of the team

Extends the life of the product Value defect prevention over defect detection

Prevent defects to save yourself the headaches later on

Final PresentationAgile PrinciplesUpdated: 25-Nov-2006


Design and Documentation Keep the design simple

Design and code for what is needed today Consider designing reusable software for future projects

UML offers a wide variety of tools to document the design Since Tcl is a scripting language, a sequence diagram can

typically be used when designing a module Extraction software such as JavaDoc can be useful

for documenting software Tcl has its own documentation utility known as AutoDOC

Developed by Andreas Kupries in 2001 as an extension to the language

Final PresentationAgile PracticesUpdated: 25-Nov-2006


The Customer

Always have the customer's input when creating software Responsible for the requirements Ability to pick which features are most important,

and therefore, should be developed first



Coding Conventions

Makes the code easy to read, especially if a new team member arrives

Ray Johnson of Sun Microsystems created a Tcl style guide for the Tcl programming language Using these coding conventions in conjunction

with the AutoDOC utility makes Tcl source code well commented and easy to read



Paired Programming Paired programming involves two people sitting at one computer

where each person can sit comfortably and work can get done. Keep one another on task Refine the system Come up with ideas When one partner is stuck the other can take over, lowering

the stress level Hold each other responsible for following the other practices

the team is following Downsides of Paired Programming

Watching another person type can be painful Many companies consider paired programming a waste of a

resource



Code Reviews

Code reviews in conjunction with paired programming allow for the whole team to own the code Allow for the team to learn and share ideas about the

project

There are downsides of code reviews without paired programming Typically logic errors are missed

A combination of paired programming and code reviews will lead to better defect prevention



Iterative and Incremental Development

“Plan a little, do a little, learn a little.” By developing the software incrementally, the

software can stay in a releasable state Putting in the most important features first,

the software could theoretically be released to the customer if they decide that some of the features initially envisioned are no longer necessary



Continuous Integration

Frequent integration insures that modules that must fit together will

Automate the build with unit tests to detect errors as soon as possible An Ant build can be created for this

A single source repository keeps the necessary items for a build together


Sample Test Target



<target name="test" depends="compile">

<exec dir="${build.scripts.dir}/unitTests“ executable="tclsh">

<arg line="unitTestsAll.tcl"/>

</exec>

</target>


Refactoring

Refactoring can improve the structure of code without changing its behavior

Martin Fowler wrote a whole book on refactoring and offers wide variety of refactorings available Most can only be applied to Object Oriented Languages Sample refactorings for scripting languages:

Add a parameter Consolidate Conditional Expression Extract Method



Unit Testing

Prevents defects from ending up in software Gives confidence that the product is behaving

as expected Tcl had two unit test frameworks available:

tcltest – does not use the xUnit framework TclTkUnit – does not report results sufficiently

“t-unit” was developed to be a better unit test framework for Tcl



t-unit

Provides an automated unit test framework Modeled after the “JUnit” Java test suite All calls are “asserts”; e.g.:

“assertEqual” checks for equal results “assertTrue” checks for result of boolean TRUE . . .and so on. . .


t-unit “Class” DiagramUpdated: 25-Nov-2006

File

Test Suite

Report

«creates»

«examines»Procedure

PackageUnder Test

Expression«calls»

«input, expected»

Test Case

+ reason: String Test Result

Pass Fail

«result»

{complete, discrete}

Package t-unit

t-unit::assertXXXX«abstract»

t-unit::testHarness«calls»

t-unit::assertEquals

t-unit::assertEqualsReal

t-unit::assertEqualsList

t-unit::assertEqualsArray t-unit::assertNotEquals

t-unit::assertFalse

t-unit::assertTrue

«test function»

«reads»

«writes»

user

«runs»


Sample Test CaseTUnit Process ModelTest Case File DescriptionUpdated: 27-Oct-2006

t-unit::assertEquals 12.34 12.34 | PASS | OKt-unit::assertEquals "hello“ "hello” | PASS | OKt-unit::assertEquals "hello“ "world“ | FAIL | NOT_EQUALt-unit::assertEquals 2 2 | PASS | OKt-unit::assertEquals 2 3 | FAIL | NOT_EQUALt-unit::assertEquals 12345 12345 | PASS | OKt-unit::assertEquals 12345 12345.0 | FAIL | ARG_MISMATCHt-unit::assertEquals TRUE TRUE | PASS | OKt-unit::assertNotEquals TRUE FALSE | PASS | OKt-unit::assertNotEquals “hello” “world” | PASS | OKt-unit::assertEqualsList {1 2 3} {1 2 3} | PASS | OKt-unit::assertEqualsArray A1 A2 | PASS | OKt-unit::assertEquals [samplePackage::addOne 1] 2 | PASS | OK

Usage notes:1. Vertical bars required as shown2. Whitespace required as shown3. Optional third parameter (not shown) allows tailoring of response message for each assertion4. Either parameter (or both parameters) may be a Tcl “list” data type

• List can contain a procedure name and its arguments• Allows testing of procedures, not just values (real strength of this package)• Enclose lists in curly braces within test file, or define globally prior to running t-unit

(may be defined as part of automated test suite)• List may comprise a procedure and its argument list

Final PresentationTest Case File DescriptionUpdated: 25-Nov-2006


Use Available Tools A wide variety of tools at our disposal

Text editors that offer syntax highlighting Office suites for presentations and UML documents

Configuration Management (CM) System Keep track of every change in source code and

documentation Allows for continuous integration to be seamless Subversion, CVS

Eclipse Open Development Platform Text editor Build and unit testing Integrated GUI for CM



TUnit TUnit is a plug-in for the Eclipse IDE. TUnit makes use of the t-unit

package that was developed for the Tcl programming language. Features:

Tcl Perspective Tcl Project Wizard – creates tcl projects with t-unit included Tcl Package Creator – creates packages within the project Tcl File Creator – creates tcl files with AutoDOC comments in place Tcl File Editor – allows for syntax highlighting, auto indentation, and content

assistance (i.e. completion of commands) Preferences menu Namespace Explorer – lists packages and files within each package; can be

used to verify that Tcl coding standards are being followed Execution of t-unit scripts

A set of unit tests is also available to test the TUnit plug-in Demonstration



TUnit Extension The Eclipse Dynamic Languages Toolkit (DLTK)

project was created to develop a framework for tool vendors, researchers, and end-users who rely on dynamic languages such as Tcl

Xored Software Inc. was behind the plug-in and they are developing the project in Russia

Eclipse DLTK did not include a unit test framework as part of the plug-in TUnit extension was born Offered to create this part of the plug-in using the t-unit

package Demonstration



Future Research Over time, more practices will be added to Agile to

make the development process even more seamless

The future of TUnit and the TUnit extension is still up in the air TUnit has been released as version 1.0.0 No bugs reported to date via the Google Code repository

TUnit extension could see additional revisions The Eclipse DLTK project is interested in adding the tcltest

framework to the TUnit extension Code is written to do this fairly easily Looking at a date in January 2007

Final PresentationFuture ResearchUpdated: 25-Nov-2006


Conclusions

Agile is not going away but getting stronger

More and more it is being accepted as a valid process for creating software

Not all the practices need to be followed: come up with a set that fits the team’s needs



Source Code TUnit has a homepage at: http://tunitplugin.googlepages.com

Project can be downloaded from here along with documentation and screenshots

Source code repository for the paper, this presentation, TUnit and the TUnit unit tests at: http://code.google.com/p/t-unit/

Eclipse DLTK considering putting the extension of TUnit in their next milestone release The source code is located in Loyola Marymount’s CVS for now

but could move into the Eclipse DLTK repository next year Could not use the Google repository because the Eclipse Public

License is not available Can also download the project at the TUnit homepage



Questions or Comments

t-unit: tcl unit test package

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