What does quality mean?
- value for some person?
- fit for purpose?
- as good as it can be?
- as bad as you can get away with?
- as good as you can get away with?
- I know it when I see it?
How to Create High Quality Software
- high quality people develop high quality software
- but this just changes the question
- for managers
- how do I manage development of high quality software?
- how do I get high quality developers to work on my project
- how do I recognise a high quality developer?
- for developers
- how do I become I high quality developer?
- a lot of it boils down to
- managers - give your developers freedom to do their jobs
- developers - use that freedom wisely
Management Responsibilities
- managers need to make it possible for developers to write high quality code
- don't tie your developers' hands behind their backs
- appropriate working conditions
- appropriate hardware
- appropriate tools
Engineers' Responsibilities
Algorithms and Data Structures
- distinguishes the great developers from the good
- The Algorithm Design Manual by Steven S. Skiena
- estimation - back of an envelope mathematics
- ADTs - Abstract Data Types
Perl
- current best practices
- recent version of perl (5.12.1)
- Use new language features unless you have a reason not to
- chose modern modules
- Moose
- Catalyst or similar
- DBIx::Class or similar
- Template toolkit or similar
Perl
- keep up to date
- mailing lists for projects you rely on
- linux
- ion
- zsh
- vim
- lists.perl.org
- local Perl Mongers group
- conferences
- books
- blogs
- IRC
- ...
Code Structure
- sub-systems
- interfaces
- classes / inheritance / roles
- methods
- encapsulation
- scope
- loose coupling (interact with other systems via defined interfaces)
- strong cohesion (do one thing and do it well)
Programming Paradigms
- procedural
- object oriented
- functional
- logical
Version Control System
- git
- mercurial
- darcs
- svk
Code Layout
- code should be beautiful
- code is crafted, not thrown together
- it should be a work of art
- tabs / spaces
- vertcal alignment
- perltidy
- helpful editor
Comments
- describe algorithms and design decisions
- code should describe itself
Class / Method / Variable names
- concise
- length related to scope
- descriptive
- unambiguous
- conventions
- one of the most difficult parts of programming
Defensive Programming
- check input
- external input
- function parameters
- error handling
- assertions
- pre and post conditions
- consider how much to leave on in production
Testing
- automated
- TDD
- unit tests
- integration tests
- non-functional tests
- load
- performance
- exploratory testing
- code coverage
Quality Assurance
- code reviews
- pair coding
- static metrics
- change control procedures
- audits
- continuous integration
Books
- Code Complete by Steven C. McConnell
- The Algorithm Design Manual by Steven S. Skiena