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Rector 1.0.0 ๐ŸŽ‰๐ŸŽ‰๐ŸŽ‰, my friend, my coach

ยท 6 min read
Markdown, WSL and Docker lover ~ PHP developer ~ Insatiable curious.

Rector 1.0.0 ๐ŸŽ‰๐ŸŽ‰๐ŸŽ‰, my friend, my coach

If there was only one, it would be Rector. Rector is extremely powerful and brilliant and, you know what, it's free!

Rector is a tremendous application to scan and automatically upgrade your codebase to a given version of PHP and this means, too, to inspect how you're coding.

Rector will look at every line of code, every loop, every conditional test, every function, every class in a PHP source code and suggest improvements.

In this role, it will not only detect improvements to my code (like a static analysis tool) but, and this is the biggest advantage for me, it will show me how I can become a better developer.


Rector can be downloaded on GitHub

Don't wait and install Rector

Like a lot of people, I learned PHP on my own and that was at the time of PHP 5. Like a lot of people, I certainly picked up some bad habits and because it's impossible to keep up with every evolution of the language, my skills don't increase at the same time as the language.

So, perhaps, I'm still using old-fashioned syntax like doing a simple if ... then ... else when in fact it's not useful. Maybe I'm going to use a variable to store a value when it's absolutely useless.

Let's take a look at a very simple example (sayHello.php):


function sayHello($firstname = '')
if ($firstname == '') {
$text = 'Hello World!';
} else {
$text = 'Hello ' . $firstname;

return $text;

echo sayHello('Christophe');

Simple and effective, isn't it? And, above all, the code is perfectly functional and well written, respecting all the layout conventions.

I'm an excellent developer. Thank you and goodbye.

Well, in fact, I was an excellent developer but I stopped being one ten years ago.

What's wrong with my code?

  • $firstname is a string no? So why not write string $firstname?,
  • since PHP 7.x, there is a thing called ternary operator; you didn't know that?,
  • Using the ternary operator; the $text variable becomes useless and
  • the function is returning a string (the $text variable) but the prototype of the function didn't mention this. So why not write function sayHello($firstname = ''): string
I'll lend you my friend, my coach, Rector

Install Rectorโ€‹

When you use composer to manage dependencies in your project, just run composer require rector/rector --dev in a console. This will install Rector as a dev-dependency (which is pretty good).

The next thing is to create a configuration file. You can use a standard one (to do this just run vendor/bin/rector and the file will be created) or create yours.

I suggest creating a rector.php file in your project with this content:



use Rector\Config\RectorConfig;

return RectorConfig::configure()
'.git', 'node_modules','vendor'
->withPhpSets(php82: true)
->withPreparedSets(codeQuality: true, deadCode: true, typeDeclarations: true);

For simplicity, create the rector.php file in your project's root directory.

Run Rectorโ€‹

Call your friend, your coach, by just running vendor/bin/rector process sayHello.php --dry-run rector.php.

Rector is simplifying our sayHello function

Let's take a look on the command:

  • vendor/bin/rector: this is the executable to start,
  • process: the action to run, it's always process,
  • sayHello.php: the file to scan. You can type . for your entire project or f.i. app when app is a folder,
  • --dry-run: ask Rector to, only, show suggestions and not to update the file and
  • rector.php: this is the name of our configuration file.

So running vendor/bin/rector process sayHello.php --dry-run rector.php is just like to ask Hey my friend and coach, please take a look to my sayHello.php script and show me how I can improve my syntax and be a better programmer. And Rector does it; quickly and without judgment.

He'll show you the changes he could make, automatically, and explain why he thinks it's better.

Applied rulesโ€‹

Take a look on the Applied rules: section at the end of the screen capture; here are the rules with a link to their explanations:


Using the ternary operator, we can often replace a if then else structure with a one-line test; the ternary operator.

function sayHello($firstname = '')
- if ($firstname == '') {
- $text = 'Hello World';
- } else {
- $text = 'Hello ' . $firstname;
- }
+ $text = $firstname == '' ? 'Hello World' : 'Hello ' . $firstname;
return $text;


I think everyone will agree: storing the value in variable $text then returned the variable is useless and it's just pollution.

function sayHello($firstname = '')
- $text = $firstname == '' ? 'Hello World' : 'Hello ' . $firstname;
- return $text;
+ return $firstname == '' ? 'Hello World' : 'Hello ' . $firstname;


When the return type can be derived (here, Rector understand we're returning a string) then the function prototype can be adapted in this way.

class SomeClass
- public function sayHello($firstname = '')
+ public function sayHello($firstname = ''): string
return $firstname == '' ? 'Hello World' : 'Hello ' . $firstname;


When a parameter is a string but not type as a string, Rector see it and suggest updating the prototype as such:

class SomeClass
- public function sayHello($firstname = ''): string
+ public function sayHello(string $firstname = ''): string
return $firstname == '' ? 'Hello World' : 'Hello ' . $firstname;

Final codeโ€‹

So, back to our console, running vendor/bin/rector process sayHello.php --dry-run rector.php will show me, in the console, the new refactored version of my code:


function sayHello(string $firstname = ''): string
return 'Hello ' . ($firstname == '' ? 'World!' : $firstname);

echo sayHello();
Am I happy with this? Oh yes!!!

Yes, I'm very happy and proud to see how my code is now better and easier to read.

Yes, I'm happy to have learned something and, now, I'll no more use a temporary variable or think to use the ternary operator.

Yes, I'm very grateful to Rector for teaching me these new approaches and making me a better programmer.

Last thing, make the changeโ€‹

Now that we've taken the time to analyze the rules that could be applied and that we think are perfectly adequate, it's time to start refactoring for real: simply remove the --dry-run flag and, thus, the final command to run is: vendor/bin/rector process sayHello.php rector.php.

You know what? I LOVE RECTOR ๐Ÿ’•

Imagine what it could do for my entire project if I run vendor/bin/rector process . --dry-run rector.php.

Learn moreโ€‹

Please visit and learn more about rules and how to configure the rector.php for your project.

There are more than 400 rules right now; see all of them here: