Introduction to Test Driven Development

Introduction to Test Driven Development

Building tests and code for a“software radio”

04/19/23 Concepts of TDD, M. Smith, ECE, University of Calgary, Canada

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Concepts

Stages in a conventional radio Stages in a software radio Goals for the “long term” project Concept of test driven development Digital rectification

Tests for integer array rectification Tests for float array rectification (C++

compiler) Tests for rectification in assembly code

More details of test driven development


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Conventional “AM” radio

AntennaPickup

LocalOscillator

Mixer Low passFilter

RectifierLow pass

Filter+ amplifier

Audio out

RF STAGE

IF STAGE

AUDIO STAGE


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Software “AM” radio concept

AntennaPickup

LocalOscillator

Mixer Low passFilter

Rectifier

Audio out

RF STAGE

IF STAGE

AUDIO STAGE

Most stages handled with high speed software

Low passFilter

+ amplifier


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Software “FM” radio concept

AntennaPickup What ever

is neededRectifier

Audio out

RF STAGE AUDIO STAGE

Most stages handled with high speed software

Low passFilter

+ amplifier


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Real “software” radio

Looking at RF stage to bring in wireless signal Software radio is the rest of it

Update communication protocols Change noise suppression characteristics “on the fly” Etc.

Excellent topic for individual presentation (8 minute talk – 10 slides max – at the end of term) or possible joint presentation (16 minute talk – 20 slides max)


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Rectification algorithm

Choices are C++ compiler in DEBUG mode

int *RectifyDEBUG(int initial[ ], int final, int N); float *RectifyDEBUG (float initial[ ], float final, int N);

C++ compiler in RELEASE mode int *RectifyRELEASE(int initial[ ], int final, int N); float *RectifyRELEASE(float initial[ ], float final, int N);

“US” in ASSEMBLY mode int *RectifyASM(int initial[ ], int final, int N); float *RectifyASM(float initial[ ], float final, int N);

“US” in OPTIMIZED ASSEMBLY mode int *RectifyOPTASM (int initial[ ], int final, int N); float *RectifyOPTASM (float initial[ ], float final, int N);


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Expected relative advantages

Compiler debug mode

Compiler release (optimized) mode

“US” – assembly mode

“US” – optimized assembly mode


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Standard testing practice

Heavy on documentationDescribe

Requirements

Design Solution

Build Solution

Test Solution

WriteAnalysis Document

WriteDesign Document

WriteTest Plan Document

TLD

TestLast

Development


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Test Driven Development

Customer Tests – personally find these hard to do Not clear if there is yet “a real process available”

Developer Tests – have found many advantages

DescribeRequirements

Design Solution

Build Solution Test Solution

WriteAcceptance Tests

WriteUnit Tests

CUSTOMER

DEVELOPER


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Lets apply TDD to rectification issue

Overall technique Decide on a particular test action Write the test(s) Write the simplest possible code to satisfy the test(s) “Refactor” the code to improve “quality”

Definition of “quality” is unclear in the literature Ease of “use” or “reuse” of code Reliable to use – “robust” My additional idea – meets speed requirements for the

embedded situation

TDD in an embedded / ubiquitous computing environment is a major part of my current research with funding from NSERC and Analog Devices


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First unit test

Can I link to a particular test file and activate the tests within that files?

This include file provides all the macros needed for the TDD environment

Simple test to indicate the test set being run.Also indicates that a link is possible


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First unit test


This include file provides defines needed for the project

Test control. Certain tests always need to be run (totally automated). Others are more difficult to automate


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First unit test


NOTE: REQUIREMENT – CUSTOMER TEST CODE MUST BE AVAILABLE TO DEVELOPER

(Does not mean customer might not have other test code


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Running the tests Need a fast – easy to use – way of switching between running the tests,

and demonstrating the working customer product


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Running the customer product code


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Test code – Report Mode

Report all tests.Success and failures

Report successes only


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Test code – test level control


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Result of “link test”

Results in VisualDSP CONSOLE WINDOW

Disassemblerwindow

Source or“Mixed mode”

window

Editor tabs selected

Projectwindow

Twinprocessors

can be controlled


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Obvious test – actually contained a hidden bug


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Integer array tests ZERO-LENGTH ARRAY

Unspecified requirement – shown as part of test functionality Function return pointer = NULL if error

condition present


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Float tests

You write the required tests for testing rectification of floating point arrays Test for correct zero-length error response Test for correct rectification operation


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Zero-length test

Modify the integer test case


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Float rectification test


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Take notes from the screen


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Speed tests – integer code versions


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Using the tests – practical approach

Just because all the tests are known, does not mean that you use all of them immediately

If you use all of them immediately, you get a lot of failure messages, which is very soul destroying I bring first test in – write the code to satisfy that test

Keep track of “defects” and “errors” as QA Bring second test in – write the code to satisfy that test

Keep track of “defects” and “errors” as QA Run all available tests to make sure nothing “broke”

Keep track of “defects” and “errors” as QA Bring third test in – write the code to satisfy that test

Keep track of “defects” and “errors” as QA Run all available tests to make sure nothing “broke”

Keep track of “defects” and “errors” as QA


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Concepts covered

Stages in a conventional radio Stages in a software radio Goals for the “long term” project Concept of test driven development Digital rectification

Tests for integer array rectification Tests for float array rectification (C++

compiler) Tests for rectification in assembly code

More details of test driven development

Introduction to Test Driven Development

Documents

int final

university of calgary

int nfloat

int nconcepts of tdd

rectifyoptasm int initial

int nus

developmentconcepts

int nc compiler