Five Principles for Engineering High Quality Software Principles for Engineering High Quality...

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© Vector Software, Inc. © Vector Software, Inc. © Vector Software, Inc. © Vector Software, Inc. © Vector Software, Inc. © Vector Software, Inc.

Five Principles for Engineering High Quality Software www.vectorcast.com

[email protected]

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> Why High Quality Software?

> 1. Use Code Coverage analysis to measure testing completeness

> 2. Improve test coverage with unit tests

> 3. Make tests easy to run, and test results easy to understand

> 4. Implement automated parallel and change based Testing

> 5. Constantly re-factor code to improve maintainability

> Q&A

Agenda

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> Q&A

Five Principles for Engineering High Quality Software

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Why high quality software?

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> Who downloads latest greatest software version? > Windows and Service Packs; Windows 10?

> So many choices > There are 200+ flash lights application in

Google Play store

> Reviews and community can kill your

product


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What is the effort to fix a bug ?

What is the impact of a bug on

your product?


Cost of fixing a bug depending of time passed since introduction.

Avoid bugs and fix bugs as early in the process as possible

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> Q&A


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The program shall switch on a LED when the input equals to 1 and switch off the LED when input equals to 0.

1. Use Code Coverage analysis to measure testing completeness

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/* This function is called before terminating the program and deallocates all acquired memory */ void CleanOnExit(Object * memory) { //... }

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> Use coverage for code completeness

> „How many test cases?” is a wrong question

> Dead code is dangerous

> Important questions? > How much code coverage is enough?

> Can we get 100% coverage from system testing only?


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> Q&A


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> Why Unit Testing?

2. Improve test coverage with unit test

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> Test units in isolation (using mocks and stubs)

> Help you really understand the design of the code

> Faster detected bug, cheaper to fix

> Instant feedback

> Simulate low-level functionality > What happens when malloc returns null?

> What happens if we pass null object to a function?

> What happens if we give boundary values?

> ...

> Reuse of code (and tests)

> Fill coverage gap with unit testing

Use Code Coverage

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> Q&A


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> Different flavours of tests are build by different engineers > Developer Tests

> Integration Tests

> System Tests

> Available test campaigns > Regression Testing

> Scripted testing

> Smoke testing

> Exploratory testing

> Guerilla testing

> Scenario testing

> Load testing

> Performance testing

> ...

> Who can run test campaigns? > Everyone or every campaign has its owner?

3. Make tests easy to run, and test results easy to understand

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> Make your test cases and reports easy to understand

> Or you want to be like this guy?

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> Make test case simple and readable

> Allow developers to run any test cases they want

> Keep it simple to run – one button, one command

> Make test results easy to understand...


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> Q&A


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> Tests are partitioned among many groups => how long does it take to run test camping ?

> Minutes, hours, days ?!

4. Implement automated parallel and change based Testing

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> Automate!

> Automation is a tool, not a strategy. > Quickly detect destabilizing changes in new builds

> Quickly, detect regression bugs

> Quickly report problems (and make fixing easier)

> Parallel Test Execution > Running hundreds of test cases at the same time

> Change-Based Testing > Running only tests affected by each software change

> Why waste resources on a few lines change?

4. Implement automated parallel and change based Testing

Save time and resources!

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What is refactoring?

> Makes code easy to understand

> Makes code easy to extend

> Speeds up creation of complicated systems

5. Constantly Refactor code to improve maintainability

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Why should I refactor?

> Remove complicated and duplicated code

> Make code easy to understand for yourself

> Make code easy to understand for others

> Extend code quicker

> Make better tests

5. Constantly re-factor code to improve maintainability

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What is code smell? "a code smell is a surface indication that usually corresponds to a deeper problem in the system„

Martin Fowler

> Duplicating code

> Dead code

> Long and complex functions > Cyclomatic complexity less than M

> ...

5. Constantly re-factor code to improve maintainability

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VectorCAST

VectorCAST Test Management Platform

ALM, Requirements Gateway

Analysis, Metrics Reporting Model-Based Development

Coverage Unit Test Static

Analysis Compiler, Debugger, RTOS, Simulator

Cluster Control

Continuous Integration

Compiler, Debugger, RTOS, Simulator

Legacy Tests

Technical Debt

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Coding

Architecture

Requirements Specification

System Design

System Testing

Integration Testing

Unit Testing

VectorCAST

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Q&A

vecto rca st . co m

Proven Solutions for Reliable Software

Questions?

www.vectorcast.com [email protected]

http://www.vectorcast.com/

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Five Principles for Engineering High Quality Software Principles for Engineering High Quality...

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