Narrow $data[$key] after specifying $key

Author: ondrejmirtes

src/Analyser/MutatingScope.php

@@ -3511,14 +3511,45 @@ private function specifyExpressionType(Expr $expr, Type $type, ?Type $nativeType
 				$conditionalExpressions[$conditionalExprString] = $holders;
 			}
 
+			$moreSpecificTypeHolders = $this->moreSpecificTypes;
+			foreach ($moreSpecificTypeHolders as $specifiedExprString => $specificTypeHolder) {
+				if (!$specificTypeHolder->getCertainty()->yes()) {
+					continue;
+				}
+
+				$specifiedExprString = (string) $specifiedExprString;
+				$specifiedExpr = $this->exprStringToExpr($specifiedExprString);
+				if ($specifiedExpr === null) {
+					continue;
+				}
+				if (!$specifiedExpr instanceof Expr\ArrayDimFetch) {
+					continue;
+				}
+
+				if (!$specifiedExpr->dim instanceof Variable) {
+					continue;
+				}
+
+				if (!is_string($specifiedExpr->dim->name)) {
+					continue;
+				}
+
+				if ($specifiedExpr->dim->name !== $variableName) {
+					continue;
+				}
+
+				$moreSpecificTypeHolders[$specifiedExprString] = VariableTypeHolder::createYes($this->getType($specifiedExpr->var)->getOffsetValueType($type));
+				unset($nativeTypes[$specifiedExprString]);
+			}
+
 			return $this->scopeFactory->create(
 				$this->context,
 				$this->isDeclareStrictTypes(),
 				$this->constantTypes,
 				$this->getFunction(),
 				$this->getNamespace(),
 				$variableTypes,
-				$this->moreSpecificTypes,
+				$moreSpecificTypeHolders,
 				$conditionalExpressions,
 				$this->inClosureBindScopeClass,
 				$this->anonymousFunctionReflection,

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -980,6 +980,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7788.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7809.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/composer-non-empty-array-after-unset.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Arrays/data/bug-6000.php');
 	}
 
 	/**

tests/PHPStan/Rules/Arrays/data/bug-6000.php

@@ -2,12 +2,16 @@
 
 namespace Bug6000;
 
+use function PHPStan\Testing\assertType;
+
 function (): void {
 	/** @var array{psr-4?: array<string, string|string[]>, classmap?: list<string>} $data */
 	$data = [];
 
 	foreach ($data as $key => $value) {
+		assertType('array<int|string, array<string>|string>', $data[$key]);
 		if ($key === 'classmap') {
+			assertType('array<int, string>', $data[$key]);
 			echo implode(', ', $value); // not working :(
 			echo implode(', ', $data[$key]); // this works though?!
 		}

tests/PHPStan/Rules/Functions/ImplodeFunctionRuleTest.php

@@ -50,13 +50,7 @@ public function testFile(): void
 
 	public function testBug6000(): void
 	{
-		$this->analyse([__DIR__ . '/../Arrays/data/bug-6000.php'], [
-			[
-				// shouldn't be happening...
-				'Parameter #2 $array of function implode expects array<string>, array<int|string, array<string>|string> given.',
-				12,
-			],
-		]);
+		$this->analyse([__DIR__ . '/../Arrays/data/bug-6000.php'], []);
 	}
 
 }