BacktickRule made auto-fixable

Author: ondrejmirtes

src/Rules/Operators/BacktickRule.php

@@ -9,6 +9,7 @@
 use PHPStan\Php\PhpVersion;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
+use PHPStan\ShouldNotHappenException;
 
 /**
  * @implements Rule<ShellExec>
@@ -34,9 +35,32 @@ public function processNode(Node $node, Scope $scope): array
 			return [];
 		}
 
+		$argExpr = null;
+		foreach ($node->parts as $part) {
+			if ($part instanceof Node\InterpolatedStringPart) {
+				$expr = new Node\Scalar\String_($part->value);
+			} else {
+				$expr = $part;
+			}
+
+			if ($argExpr === null) {
+				$argExpr = $expr;
+				continue;
+			}
+
+			$argExpr = new Node\Expr\BinaryOp\Concat($argExpr, $expr);
+		}
+
+		if ($argExpr === null) {
+			throw new ShouldNotHappenException();
+		}
+
 		return [
 			RuleErrorBuilder::message('Backtick operator is deprecated in PHP 8.5. Use shell_exec() function call instead.')
 				->identifier('backtick.deprecated')
+				->fixNode($node, static fn () => new Node\Expr\FuncCall(new Node\Name('shell_exec'), [
+					new Node\Arg($argExpr),
+				]))
 				->build(),
 		];
 	}

tests/PHPStan/Rules/Operators/BacktickRuleTest.php

@@ -5,6 +5,7 @@
 use PHPStan\Php\PhpVersion;
 use PHPStan\Rules\Rule;
 use PHPStan\Testing\RuleTestCase;
+use PHPUnit\Framework\Attributes\RequiresPhp;
 use const PHP_VERSION_ID;
 
 /**
@@ -27,9 +28,23 @@ public function testRule(): void
 					'Backtick operator is deprecated in PHP 8.5. Use shell_exec() function call instead.',
 					4,
 				],
+				[
+					'Backtick operator is deprecated in PHP 8.5. Use shell_exec() function call instead.',
+					5,
+				],
+				[
+					'Backtick operator is deprecated in PHP 8.5. Use shell_exec() function call instead.',
+					6,
+				],
 			];
 		}
 		$this->analyse([__DIR__ . '/data/backtick.php'], $errors);
 	}
 
+	#[RequiresPhp('>= 8.5')]
+	public function testFix(): void
+	{
+		$this->fix(__DIR__ . '/data/backtick.php', __DIR__ . '/data/backtick.php.fixed');
+	}
+
 }

tests/PHPStan/Rules/Operators/data/backtick.php

@@ -1,5 +1,7 @@
 <?php
 
-function (): void {
+function (string $s, string $t): void {
 	`echo "foo";`;
+	`$s $a`;
+	`$s $a foo $t`;
 };

tests/PHPStan/Rules/Operators/data/backtick.php.fixed

@@ -0,0 +1,7 @@
+<?php
+
+function (string $s, string $t): void {
+	shell_exec('echo "foo";');
+	shell_exec($s . ' ' . $a);
+	shell_exec($s . ' ' . $a . ' foo ' . $t);
+};