From b96374daf7f3a0333283a2643eab6094d094197d Mon Sep 17 00:00:00 2001
From: Martin Herndl <martin@herndl.org>
Date: Thu, 1 Sep 2022 09:46:49 +0200
Subject: [PATCH 1/2] Add array_fill_keys tests for union and optional constant
 array keys

---
 .../PHPStan/Analyser/data/array-fill-keys.php | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tests/PHPStan/Analyser/data/array-fill-keys.php b/tests/PHPStan/Analyser/data/array-fill-keys.php
index 739c7e8deb..fcf82d1094 100644
--- a/tests/PHPStan/Analyser/data/array-fill-keys.php
+++ b/tests/PHPStan/Analyser/data/array-fill-keys.php
@@ -51,6 +51,28 @@ function withObjectKey() : array
 	assertType("*NEVER*", array_fill_keys([new Baz()], 'b'));
 }
 
+function withUnionKeys(): void
+{
+	$arr1 = ['foo', rand(0, 1) ? 'bar1' : 'bar2', 'baz'];
+	assertType("non-empty-array<'bar1'|'bar2'|'baz'|'foo', 'b'>", array_fill_keys($arr1, 'b'));
+
+	$arr2 = ['foo'];
+	if (rand(0, 1)) {
+		$arr2[] = 'bar';
+	}
+	$arr2[] = 'baz';
+	assertType("non-empty-array<'bar'|'baz'|'foo', 'b'>", array_fill_keys($arr2, 'b'));
+}
+
+function withOptionalKeys(): void
+{
+	$arr1 = ['foo', 'bar'];
+	if (rand(0, 1)) {
+		$arr1[] = 'baz';
+	}
+	assertType("array{foo: 'b', bar: 'b', baz?: 'b'}", array_fill_keys($arr1, 'b'));
+}
+
 /**
  * @param Bar[] $foo
  * @param int[] $bar

From a39e5701ad8c6e54713b9f0b18fb7528b07eba21 Mon Sep 17 00:00:00 2001
From: Martin Herndl <martin@herndl.org>
Date: Thu, 1 Sep 2022 09:47:25 +0200
Subject: [PATCH 2/2] Use TypeUtils::getOldConstantArrays in array_fill_keys
 extension

---
 src/Type/Php/ArrayFillKeysFunctionReturnTypeExtension.php | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/Type/Php/ArrayFillKeysFunctionReturnTypeExtension.php b/src/Type/Php/ArrayFillKeysFunctionReturnTypeExtension.php
index b1863e1db4..e912e4b828 100644
--- a/src/Type/Php/ArrayFillKeysFunctionReturnTypeExtension.php
+++ b/src/Type/Php/ArrayFillKeysFunctionReturnTypeExtension.php
@@ -33,7 +33,7 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 
 		$valueType = $scope->getType($functionCall->getArgs()[1]->value);
 		$keysType = $scope->getType($functionCall->getArgs()[0]->value);
-		$constantArrays = TypeUtils::getConstantArrays($keysType);
+		$constantArrays = TypeUtils::getOldConstantArrays($keysType);
 		if (count($constantArrays) === 0) {
 			if ($keysType->isArray()->yes()) {
 				$itemType = $keysType->getIterableValueType();
@@ -53,15 +53,15 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 		$arrayTypes = [];
 		foreach ($constantArrays as $constantArray) {
 			$arrayBuilder = ConstantArrayTypeBuilder::createEmpty();
-			foreach ($constantArray->getValueTypes() as $keyType) {
+			foreach ($constantArray->getValueTypes() as $i => $keyType) {
 				if ((new IntegerType())->isSuperTypeOf($keyType)->no()) {
 					if ($keyType->toString() instanceof ErrorType) {
 						return new NeverType();
 					}
 
-					$arrayBuilder->setOffsetValueType($keyType->toString(), $valueType);
+					$arrayBuilder->setOffsetValueType($keyType->toString(), $valueType, $constantArray->isOptionalKey($i));
 				} else {
-					$arrayBuilder->setOffsetValueType($keyType, $valueType);
+					$arrayBuilder->setOffsetValueType($keyType, $valueType, $constantArray->isOptionalKey($i));
 				}
 			}
 			$arrayTypes[] = $arrayBuilder->getArray();