Upgrade to PHP 8.5

Raise the PHP version in composer.json to 8.5, and DressCode rewrites your code to the pipe operator, array_first(), array_last() and clone() with properties. It also fixes or reports everything PHP 8.5 deprecated, and formats the result by your coding standard in the same run.

What It Looks Like

A class written for PHP 8.4, in a project that now requires PHP 8.5. The configuration adds the sets modernizations and deprecations to the standard and says that the namespaces of the project declare no functions of their own; the target PHP version, which DressCode otherwise takes from composer.json, is given here by the key targets:

use:
	- perCs
	- modernizations
	- deprecations

nameResolution: certain

targets:
	php: '8.5'

final class Article
{
    private string $title = '';

    /** @var list<Item> */
    private array $items = [];

    public function withTitle(string $title): static
    {
        $clone = clone $this;
        $clone->title = $title;
        return $clone;
    }

    public function slug(string $title): string
    {
        return trim(strtolower(strip_tags($title)));
    }

    public function newest(): Item
    {
        return $this->items[array_key_last($this->items)];
    }

    public function download(string $url): string
    {
        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        $data = (string) curl_exec($ch);
        curl_close($ch);
        return $data;
    }

    public function count(): int
    {
        return (integer) count($this->items);
    }
}

After one dresscode fix:

final class Article
{
    private string $title = '';

    /** @var list<Item> */
    private array $items = [];

    public function withTitle(string $title): static
    {
        return clone($this, ['title' => $title]);
    }

    public function slug(string $title): string
    {
        return $title |> strip_tags(...) |> strtolower(...) |> trim(...);
    }

    public function newest(): Item
    {
        return array_last($this->items);
    }

    public function download(string $url): string
    {
        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        $data = (string) curl_exec($ch);
        return $data;
    }

    public function count(): int
    {
        return (int) count($this->items);
    }
}

Each change is one item of PHP 8.5: clone() with properties, the pipe operator |>, the function array_last(), the call of curl_close() that no longer does anything, and the cast (integer), which PHP 8.5 deprecated.

What Gets Rewritten

The set modernizations rewrites code to what PHP 8.5 brought. Each item is a decision of the section upgrading that a project can also turn on alone.

Every decision knows the PHP version that brought its feature. While composer.json still allows PHP 8.4, the rewrites to 8.5 wait quietly, and dresscode config lists them as having no effect.

What PHP 8.5 Deprecated

The set deprecations fixes what has a direct replacement and reports the rest, with the version that deprecated it. Methods of PHP classes are rewritten only where DressCode knows the type of the object, see Types from PHPStan.

A finding names the version that deprecated the thing:

src/Db.php:19:5: error: Function `mysqli_execute()` is deprecated: since PHP 8.5. [upgrading.php.deprecatedApi]

Risky Fixes

A rewrite that may change what the code does is only reported, and made once you list its decision in fixRisky. The attribute #[\Deprecated] is such a case by its nature, because the deprecated code starts reporting at runtime:

fixRisky:
	- upgrading.phpdoc.deprecated

In a namespace, an unqualified strip_tags() may be a function of that namespace. Until the configuration says nameResolution: certain, the rewrites of such calls wait as risky, see Functions and Constants in Namespaces.

Step by Step

1. Start with a clean working tree, so that the diff shows only what DressCode did.
2. Measure how much work the move takes: dresscode upgrade php 8.5. If the project sets config.platform.php, raise it to 8.5 first.
3. Save the plan and carry it out: dresscode upgrade php 8.5 --save-plan, then dresscode upgrade --continue. At the Composer step, DressCode asks whether it may raise require.php to ^8.5; you can also raise it yourself and then run --continue.
4. Read what is left for you, and run --continue again until the run ends with UPGRADED. The risky fixes that wait are decided by the types, by nameResolution, or by you.
5. Commit the result on its own, without other changes.

If the project has the sets modernizations and deprecations in its configuration, a plain dresscode fix after raising require.php is enough. Upgrade Your Code Step by Step describes the whole procedure with tests and commits.

Where to Go Next

• Upgrading to a newer PHP, PHP 8.6 and 8.4 as well as older versions.
• Types from PHPStan, so that methods of PHP classes are rewritten too.
• The section upgrading with every decision about a newer PHP.