Coding Standards

What they are and why they're important

Jonathan Desrosiers - @Desrosj

Me

Developer
Work at Boston University
WordCamp and WordPress Boston Organizer
Using WordPress 10 years
Core Contributor
Multisite & Media contributor
Leads New Core Contributor meetings in #core

What We'll Cover

Educate
- What are best practices?
- Why should I use them?
- How do they help me?
Demonstrate
- What tools are available to help enforce standards?

Ninety-Ninety Rule

“The first 90% of the code accounts for the first 90% of the development time. The remaining 10% of the code accounts for the other 90% of the development time.”

- Tim Cargill - Bell Labs

Translation

Estimating development is HARD!

What are Coding Standards?

Guidelines for a specific programming language that dictates:

style
practices
methods

What are Coding Standards?

File organization
Indentation
Comments
Whitespace
Naming conventions
etc.

Examples

Tabs should be used at the beginning of the line for indentation

Examples

Braces shall be used for all code blocks, even when they are not required.

if ( some condition ) {
    action1();
    action2();
} elseif ( another condition ) {
    action3();
    action4();
} else {
    default_action();
}

What are Best Practices?

A set of informal rules that the software development community has learned over time that can help improve the quality of software.

What are Best Practices?

~~A set of informal rules that the software development community has~~ learned ~~over time that can help improve the quality of software.~~

Examples

Don't query all posts at once.

$dangerous_post_query = new WP_Query(
    array(
        'post_type'      => 'post',
        'posts_per_page' => -1,
    )
);

Examples

$dangerous_post_query = new WP_Query(
    array(
        'post_type'      => 'post',
        'posts_per_page' => 100,
    )
);

Don't query all posts at once.

Coding Standards

Best Practices

Increased Software Quality

How do these help?

Readability
Compatibility
Maintainability

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These become easier:

Code reviews
Debugging
Refactoring

These become easier (Business):

Onboarding new employees
Outsourcing work

These become easier:

Open sourcing projects becomes more enjoyable
Contributing to WordPress becomes less intimidating
Lower barrier of entry for automated tools

Questions?

But WordPress does not even follow the coding standards in Core. Why should I?

Tools

Try it out

<?php

function test() {
  $welcome_message_1='Hello there!';
  $welcome_message_2 = 'Welcome!';

if(in_array(date('w'), array(0,6)))
  echo $welcome_message_1;
else
  echo $welcome_message_2;
}
?>

Autofixing

<?php

function test() {
  $welcome_message_1 = 'Hello there!';
  $welcome_message_2 = 'Welcome!';

  if ( in_array( date( 'w' ), array( 0, 6 ) ) ) {
    echo $welcome_message_1;
  } else {
    echo $welcome_message_2;
  }
}