Keep benevolent union array key type with Foo[] after non-empty check

ondrejmirtes · ondrejmirtes · commit 58a336fe8563 · 2020-08-24T23:04:34.000+02:00
diff --git a/src/Type/TypeCombinator.php b/src/Type/TypeCombinator.php
@@ -620,6 +620,20 @@ private static function reduceArrays(array $constantArrays): array
 
 	public static function intersect(Type ...$types): Type
 	{
+		usort($types, static function (Type $a, Type $b): int {
+			if (!$a instanceof UnionType || !$b instanceof UnionType) {
+				return 0;
+			}
+
+			if ($a instanceof BenevolentUnionType) {
+				return 1;
+			}
+			if ($b instanceof BenevolentUnionType) {
+				return -1;
+			}
+
+			return 0;
+		});
 		// transform A & (B | C) to (A & B) | (A & C)
 		foreach ($types as $i => $type) {
 			if ($type instanceof UnionType) {
@@ -632,7 +646,12 @@ public static function intersect(Type ...$types): Type
 					);
 				}
 
-				return self::union(...$topLevelUnionSubTypes);
+				$union = self::union(...$topLevelUnionSubTypes);
+				if ($type instanceof BenevolentUnionType) {
+					return TypeUtils::toBenevolentUnion($union);
+				}
+
+				return $union;
 			}
 		}
 
diff --git a/tests/PHPStan/Analyser/NodeScopeResolverTest.php b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
@@ -9405,11 +9405,11 @@ public function dataPhp73Functions(): array
 				'array_key_last($mixedArray)',
 			],
 			[
-				'int|string',
+				'(int|string)',
 				'array_key_first($nonEmptyArray)',
 			],
 			[
-				'int|string',
+				'(int|string)',
 				'array_key_last($nonEmptyArray)',
 			],
 			[
@@ -10028,6 +10028,11 @@ public function dataClassPhpDocs(): array
 		return $this->gatherAssertTypes(__DIR__ . '/data/classPhpDocs.php');
 	}
 
+	public function dataNonEmptyArrayKeyType(): array
+	{
+		return $this->gatherAssertTypes(__DIR__ . '/data/non-empty-array-key-type.php');
+	}
+
 	/**
 	 * @dataProvider dataBug2574
 	 * @dataProvider dataBug2577
@@ -10092,6 +10097,7 @@ public function dataClassPhpDocs(): array
 	 * @dataProvider dataMinMaxReturnTypeWithArrays
 	 * @dataProvider dataNativeStaticReturnType
 	 * @dataProvider dataClassPhpDocs
+	 * @dataProvider dataNonEmptyArrayKeyType
 	 * @param string $assertType
 	 * @param string $file
 	 * @param mixed ...$args
diff --git a/tests/PHPStan/Analyser/data/non-empty-array-key-type.php b/tests/PHPStan/Analyser/data/non-empty-array-key-type.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace NonEmptyArrayKeyType;
+
+use function PHPStan\Analyser\assertType;
+
+class Foo
+{
+
+	/**
+	 * @param \stdClass[] $items
+	 */
+	public function doFoo(array $items)
+	{
+		assertType('array<stdClass>', $items);
+
+		if (count($items) > 0) {
+			assertType('array<stdClass>&nonEmpty', $items);
+			foreach ($items as $i => $val) {
+				assertType('(int|string)', $i);
+				assertType('stdClass', $val);
+			}
+		}
+	}
+
+	/**
+	 * @param \stdClass[] $items
+	 */
+	public function doBar(array $items)
+	{
+		foreach ($items as $i => $val) {
+			assertType('(int|string)', $i);
+			assertType('stdClass', $val);
+		}
+	}
+
+}
diff --git a/tests/PHPStan/Type/TypeCombinatorTest.php b/tests/PHPStan/Type/TypeCombinatorTest.php
@@ -2782,6 +2782,14 @@ public function dataIntersect(): array
 				IntersectionType::class,
 				'string&hasOffset(int)',
 			],
+			[
+				[
+					new BenevolentUnionType([new IntegerType(), new StringType()]),
+					new MixedType(),
+				],
+				BenevolentUnionType::class,
+				'(int|string)',
+			],
 		];
 	}
 
