Add RemoveDeadVarThisFixer (#23)

Author: TomasVotruba

packages/coding-standard/src/Fixer/Commenting/RemoveDeadVarThisFixer.php

@@ -0,0 +1,51 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Symplify\CodingStandard\Fixer\Commenting;
+
+use PhpCsFixer\DocBlock\DocBlock;
+use PhpCsFixer\FixerDefinition\FixerDefinition;
+use PhpCsFixer\FixerDefinition\FixerDefinitionInterface;
+use PhpCsFixer\Tokenizer\Token;
+use PhpCsFixer\Tokenizer\Tokens;
+use Symplify\CodingStandard\Utils\Regex;
+
+/**
+ * Removes a dead inline var doc block that types the "$this" variable - it carries no
+ * information, as the type of "$this" is already known from the surrounding class.
+ *
+ * @see \Symplify\CodingStandard\Tests\Fixer\Commenting\RemoveDeadVarThisFixer\RemoveDeadVarThisFixerTest
+ */
+final class RemoveDeadVarThisFixer extends AbstractDocBlockFixer
+{
+    private const string ERROR_MESSAGE = 'Remove a dead inline "@var ... $this" doc block';
+
+    /**
+     * @see https://regex101.com/r/Hk4lFc/2
+     */
+    private const string VAR_THIS_REGEX = '#@(?:psalm-|phpstan-)?var\b[^\n]*\$this\b#';
+
+    public function getDefinition(): FixerDefinitionInterface
+    {
+        return new FixerDefinition(self::ERROR_MESSAGE, []);
+    }
+
+    /**
+     * @param Tokens<Token> $tokens
+     */
+    protected function processDocContent(string $docContent, Tokens $tokens, int $position): string
+    {
+        $docBlock = new DocBlock($docContent);
+
+        foreach ($docBlock->getLines() as $line) {
+            if (! Regex::match($line->getContent(), self::VAR_THIS_REGEX)) {
+                continue;
+            }
+
+            $line->remove();
+        }
+
+        return $docBlock->getContent();
+    }
+}

packages/coding-standard/tests/Fixer/Commenting/RemoveDeadVarThisFixer/Fixture/multi_line_var_this.php.inc

@@ -0,0 +1,24 @@
+<?php
+
+namespace Symplify\CodingStandard\Tests\Fixer\Commenting\RemoveDeadVarThisFixer\Fixture;
+
+function anotherFunction()
+{
+    /**
+     * @var SomeType $this
+     */
+    $this->run();
+}
+
+?>
+-----
+<?php
+
+namespace Symplify\CodingStandard\Tests\Fixer\Commenting\RemoveDeadVarThisFixer\Fixture;
+
+function anotherFunction()
+{
+    $this->run();
+}
+
+?>

packages/coding-standard/tests/Fixer/Commenting/RemoveDeadVarThisFixer/Fixture/single_line_var_this.php.inc

@@ -0,0 +1,22 @@
+<?php
+
+namespace Symplify\CodingStandard\Tests\Fixer\Commenting\RemoveDeadVarThisFixer\Fixture;
+
+function someFunction()
+{
+    /** @var SomeType $this */
+    $this->run();
+}
+
+?>
+-----
+<?php
+
+namespace Symplify\CodingStandard\Tests\Fixer\Commenting\RemoveDeadVarThisFixer\Fixture;
+
+function someFunction()
+{
+    $this->run();
+}
+
+?>

packages/coding-standard/tests/Fixer/Commenting/RemoveDeadVarThisFixer/Fixture/skip_var_other_variable.php.inc

@@ -0,0 +1,9 @@
+<?php
+
+namespace Symplify\CodingStandard\Tests\Fixer\Commenting\RemoveDeadVarThisFixer\Fixture;
+
+function skipFunction()
+{
+    /** @var SomeType $value */
+    $value = create();
+}

packages/coding-standard/tests/Fixer/Commenting/RemoveDeadVarThisFixer/RemoveDeadVarThisFixerTest.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Symplify\CodingStandard\Tests\Fixer\Commenting\RemoveDeadVarThisFixer;
+
+use Iterator;
+use PHPUnit\Framework\Attributes\DataProvider;
+use Symplify\EasyCodingStandard\Testing\PHPUnit\AbstractCheckerTestCase;
+
+final class RemoveDeadVarThisFixerTest extends AbstractCheckerTestCase
+{
+    #[DataProvider('provideData')]
+    public function test(string $filePath): void
+    {
+        $this->doTestFile($filePath);
+    }
+
+    public static function provideData(): Iterator
+    {
+        return self::yieldFiles(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfig(): string
+    {
+        return __DIR__ . '/config/configured_rule.php';
+    }
+}

packages/coding-standard/tests/Fixer/Commenting/RemoveDeadVarThisFixer/config/configured_rule.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+use Symplify\CodingStandard\Fixer\Commenting\RemoveDeadVarThisFixer;
+use Symplify\EasyCodingStandard\Config\ECSConfig;
+
+return static function (ECSConfig $ecsConfig): void {
+    $ecsConfig->rule(RemoveDeadVarThisFixer::class);
+};

src/Config/Level/DocblockLevel.php

@@ -22,6 +22,7 @@
 use Symplify\CodingStandard\Fixer\Commenting\DoubleAsteriskInlineVarFixer;
 use Symplify\CodingStandard\Fixer\Commenting\FixParamNameTypoFixer;
 use Symplify\CodingStandard\Fixer\Commenting\RemoveDeadParamFixer;
+use Symplify\CodingStandard\Fixer\Commenting\RemoveDeadVarThisFixer;
 use Symplify\CodingStandard\Fixer\Commenting\RemoveParamNameReferenceFixer;
 use Symplify\CodingStandard\Fixer\Commenting\RemoveSuperfluousReturnNameFixer;
 use Symplify\CodingStandard\Fixer\Commenting\RemoveSuperfluousVarNameFixer;
@@ -44,7 +45,9 @@ final class DocblockLevel
     public const array RULES = [
         // inline @var
         DoubleAsteriskInlineVarFixer::class,
+        RemoveDeadVarThisFixer::class,
         SingleLineInlineVarDocBlockFixer::class,
+
         AddMissingVarNameFixer::class,
 
         // @param