Fix array_key_first/array_key_last offset check for non-variable expressions

- The special-case logic in NonexistentOffsetInArrayDimFetchRule that suppresses
  false positives for $arr[array_key_first($arr)] only matched Variable AST nodes
- Changed expression comparison to use ExprPrinter so it works with property
  fetches, static property fetches, and any other expression type
- Also fixed the same limitation in the array_rand and count()-1 special cases
- New regression test in tests/PHPStan/Rules/Arrays/data/bug-14390.php

Author: phpstan-bot

src/Rules/Arrays/NonexistentOffsetInArrayDimFetchRule.php

@@ -10,6 +10,7 @@
 use PHPStan\DependencyInjection\AutowiredParameter;
 use PHPStan\DependencyInjection\RegisteredRule;
 use PHPStan\Internal\SprintfHelper;
+use PHPStan\Node\Printer\ExprPrinter;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
 use PHPStan\Rules\RuleLevelHelper;
@@ -33,6 +34,7 @@ final class NonexistentOffsetInArrayDimFetchRule implements Rule
 	public function __construct(
 		private RuleLevelHelper $ruleLevelHelper,
 		private NonexistentOffsetInArrayDimFetchCheck $nonexistentOffsetInArrayDimFetchCheck,
+		private ExprPrinter $exprPrinter,
 		#[AutowiredParameter]
 		private bool $reportMaybes,
 	)
@@ -120,10 +122,7 @@ public function processNode(Node $node, Scope $scope): array
 			$arrayArg = $node->dim->getArgs()[0]->value;
 			$arrayType = $scope->getType($arrayArg);
 			if (
-				$arrayArg instanceof Node\Expr\Variable
-				&& $node->var instanceof Node\Expr\Variable
-				&& is_string($arrayArg->name)
-				&& $arrayArg->name === $node->var->name
+				$this->exprPrinter->printExpr($arrayArg) === $this->exprPrinter->printExpr($node->var)
 				&& $arrayType->isArray()->yes()
 				&& $arrayType->isIterableAtLeastOnce()->yes()
 			) {
@@ -146,10 +145,7 @@ public function processNode(Node $node, Scope $scope): array
 			$arrayType = $scope->getType($arrayArg);
 
 			if (
-				$arrayArg instanceof Node\Expr\Variable
-				&& $node->var instanceof Node\Expr\Variable
-				&& is_string($arrayArg->name)
-				&& $arrayArg->name === $node->var->name
+				$this->exprPrinter->printExpr($arrayArg) === $this->exprPrinter->printExpr($node->var)
 				&& $arrayType->isArray()->yes()
 				&& $arrayType->isIterableAtLeastOnce()->yes()
 				&& ($numArg === null || $one->isSuperTypeOf($scope->getType($numArg))->yes())
@@ -170,10 +166,7 @@ public function processNode(Node $node, Scope $scope): array
 			$arrayArg = $node->dim->left->getArgs()[0]->value;
 			$arrayType = $scope->getType($arrayArg);
 			if (
-				$arrayArg instanceof Node\Expr\Variable
-				&& $node->var instanceof Node\Expr\Variable
-				&& is_string($arrayArg->name)
-				&& $arrayArg->name === $node->var->name
+				$this->exprPrinter->printExpr($arrayArg) === $this->exprPrinter->printExpr($node->var)
 				&& $arrayType->isList()->yes()
 				&& $arrayType->isIterableAtLeastOnce()->yes()
 			) {

tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php

@@ -2,6 +2,8 @@
 
 namespace PHPStan\Rules\Arrays;
 
+use PHPStan\Node\Printer\ExprPrinter;
+use PHPStan\Node\Printer\Printer;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleLevelHelper;
 use PHPStan\Testing\RuleTestCase;
@@ -44,6 +46,7 @@ protected function getRule(): Rule
 				reportPossiblyNonexistentGeneralArrayOffset: $this->reportPossiblyNonexistentGeneralArrayOffset,
 				reportPossiblyNonexistentConstantArrayOffset: $this->reportPossiblyNonexistentConstantArrayOffset,
 			),
+			new ExprPrinter(new Printer()),
 			true,
 		);
 	}
@@ -1277,4 +1280,12 @@ public function testBug14308(): void
 		$this->analyse([__DIR__ . '/data/bug-14308.php'], []);
 	}
 
+	#[RequiresPhp('>= 8.2')]
+	public function testBug14390(): void
+	{
+		$this->reportPossiblyNonexistentGeneralArrayOffset = true;
+
+		$this->analyse([__DIR__ . '/data/bug-14390.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Arrays/data/bug-14390.php

@@ -0,0 +1,55 @@
+<?php // lint >= 8.2
+
+declare(strict_types = 1);
+
+namespace Bug14390;
+
+readonly class Sample
+{
+	/**
+	 * @param array<string, string> $fields
+	 */
+	public function __construct(
+		public array $fields = [],
+	) {
+	}
+}
+
+class Foo
+{
+	public function bar(
+		Sample $sample,
+	): void {
+		if ($sample->fields !== []) {
+			echo $sample->fields[array_key_first($sample->fields)];
+		}
+	}
+
+	/**
+	 * @param array<string, string> $fields
+	 */
+	public function zoo(
+		array $fields,
+	): void {
+		if ($fields !== []) {
+			echo $fields[array_key_first($fields)];
+		}
+	}
+
+	public function withKey(
+		Sample $sample,
+	): void {
+		if ($sample->fields !== []) {
+			$key = array_key_first($sample->fields);
+			echo $sample->fields[$key];
+		}
+	}
+
+	public function arrayKeyLast(
+		Sample $sample,
+	): void {
+		if ($sample->fields !== []) {
+			echo $sample->fields[array_key_last($sample->fields)];
+		}
+	}
+}