Fix various things around isset() and ArrayDimFetch

* add regression tests for phpstan/phpstan#7000

* specify expression even it doesn't change types

* skip UnionType offset because it's hard to solve in some cases

* skip specified expressions in NonexistentOffsetInArrayDimFetchRule

* fix tests

* add regression tests

* fix useless call in foreach

* fix issue-7190 too

* Avoided duplicate namespace

Co-authored-by: Ondřej Mirtes <ondrej@mirtes.cz>

src/Analyser/MutatingScope.php

@@ -4292,14 +4292,19 @@ public function specifyExpressionType(Expr $expr, Type $type, ?Type $nativeType
 			$constantArrays = TypeUtils::getOldConstantArrays($this->getType($expr->var));
 			if (count($constantArrays) > 0) {
 				$setArrays = [];
-				$dimType = $this->getType($expr->dim);
-				foreach ($constantArrays as $constantArray) {
-					$setArrays[] = $constantArray->setOffsetValueType($dimType, $type);
+				$dimType = ArrayType::castToArrayKeyType($this->getType($expr->dim));
+				if (!$dimType instanceof UnionType) {
+					foreach ($constantArrays as $constantArray) {
+						$setArrays[] = $constantArray->setOffsetValueType(
+							TypeCombinator::intersect($dimType, $constantArray->getKeyType()),
+							$type,
+						);
+					}
+					$scope = $this->specifyExpressionType(
+						$expr->var,
+						TypeCombinator::union(...$setArrays),
+					);
 				}
-				$scope = $this->specifyExpressionType(
-					$expr->var,
-					TypeCombinator::union(...$setArrays),
-				);
 			}
 		}
 
@@ -4470,15 +4475,13 @@ public function invalidateMethodsOnExpression(Expr $expressionToInvalidate): sel
 	public function removeTypeFromExpression(Expr $expr, Type $typeToRemove): self
 	{
 		$exprType = $this->getType($expr);
-		$typeAfterRemove = TypeCombinator::remove($exprType, $typeToRemove);
 		if (
-			!$expr instanceof Variable
-			&& $exprType->equals($typeAfterRemove)
-			&& !$exprType instanceof ErrorType
-			&& !$exprType instanceof NeverType
+			$exprType instanceof NeverType ||
+			$typeToRemove instanceof NeverType
 		) {
 			return $this;
 		}
+		$typeAfterRemove = TypeCombinator::remove($exprType, $typeToRemove);
 		$scope = $this->specifyExpressionType(
 			$expr,
 			$typeAfterRemove,

src/Rules/Arrays/NonexistentOffsetInArrayDimFetchRule.php

@@ -83,7 +83,7 @@ public function processNode(Node $node, Scope $scope): array
 			return [];
 		}
 
-		if ($dimType === null) {
+		if ($dimType === null || $scope->isSpecified($node)) {
 			return [];
 		}
 

src/Rules/IssetCheck.php

@@ -86,13 +86,9 @@ public function check(Expr $expr, Scope $scope, string $operatorDescription, cal
 				)->build();
 			}
 
-			if ($hasOffsetValue->maybe()) {
-				return null;
-			}
-
 			// If offset is cannot be null, store this error message and see if one of the earlier offsets is.
 			// E.g. $array['a']['b']['c'] ?? null; is a valid coalesce if a OR b or C might be null.
-			if ($hasOffsetValue->yes()) {
+			if ($hasOffsetValue->yes() || $scope->isSpecified($expr)) {
 				if ($error !== null) {
 					return $error;
 				}

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -832,6 +832,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-3853.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/conditional-types.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/constant-array-optional-set.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7000.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-6383.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Methods/data/bug-3284.php');
 

tests/PHPStan/Analyser/data/bug-7000.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Bug7000Analyser;
+
+use function PHPStan\Testing\assertType;
+
+class Foo
+{
+	public function doBar(): void
+	{
+		/** @var array{require?: array<string, string>, require-dev?: array<string, string>} $composer */
+		$composer = array();
+		foreach (array('require', 'require-dev') as $linkType) {
+			if (isset($composer[$linkType])) {
+				assertType('array{require?: array<string, string>, require-dev?: array<string, string>}', $composer);
+				foreach ($composer[$linkType] as $x) {}
+			}
+		}
+	}
+}

tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php

@@ -382,4 +382,19 @@ public function testBug4885(): void
 		$this->analyse([__DIR__ . '/data/bug-4885.php'], []);
 	}
 
+	public function testBug7000(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-7000.php'], [
+			[
+				"Offset 'require'|'require-dev' does not exist on array{require?: array<string, string>, require-dev?: array<string, string>}.",
+				16,
+			],
+		]);
+	}
+
+	public function testBug6508(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-6508.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Arrays/data/bug-6508.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Bug6508;
+
+class Foo
+{
+	/**
+	 * @param array{
+	 *   type1?: array{bool: bool},
+	 *   type2?: array{bool: bool}
+	 * } $types
+	 * @param 'type1'|'type2' $type
+	 */
+	function test(array $types, string $type): void
+	{
+		if (isset($types[$type]) && $types[$type]['bool']) {}
+	}
+}

tests/PHPStan/Rules/Arrays/data/bug-7000.php

@@ -0,0 +1,20 @@
+<?php declare(strict_types = 1);
+
+namespace Bug7000;
+
+class Foo
+{
+	public function doBar(): void
+	{
+		/** @var array{require?: array<string, string>, require-dev?: array<string, string>} $composer */
+		$composer = array();
+		/** @var 'require'|'require-dev' $foo */
+		$foo = '';
+		foreach (array('require', 'require-dev') as $linkType) {
+			if (isset($composer[$linkType])) {
+				foreach ($composer[$linkType] as $x) {} // should not report error
+				foreach ($composer[$foo] as $x) {} // should report error. It can be $linkType = 'require', $foo = 'require-dev'
+			}
+		}
+	}
+}

tests/PHPStan/Rules/Properties/data/bug-7190.php

@@ -0,0 +1,22 @@
+<?php declare(strict_types = 1); // lint >= 7.4
+
+namespace Bug7190;
+
+interface MyObject {
+	public function getId(): int;
+}
+
+class HelloWorld
+{
+	/**
+	 * @param array<int, int> $array
+	 */
+	public function sayHello(array $array, MyObject $object): int
+	{
+		if (!isset($array[$object->getId()])) {
+			return 1;
+		}
+
+		return $array[$object->getId()] ?? 2;
+	}
+}

tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php

@@ -322,4 +322,21 @@ public function testBug7109Strict(): void
 		]);
 	}
 
+	public function testBug7190(): void
+	{
+		if (PHP_VERSION_ID < 70400) {
+			$this->markTestSkipped('Test requires PHP 7.4.');
+		}
+
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->strictUnnecessaryNullsafePropertyFetch = false;
+
+		$this->analyse([__DIR__ . '/../Properties/data/bug-7190.php'], [
+			[
+				'Offset int on array<int, int> on left side of ?? always exists and is not nullable.',
+				20,
+			],
+		]);
+	}
+
 }