Convert non-empty-arrays resulting from array_filter() to non-nullable

Author: zonuexe

src/Type/Php/ArrayFindFunctionReturnTypeExtension.php

@@ -32,9 +32,10 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 			return null;
 		}
 
-		$resultTypes = $scope->getType(new FuncCall(new Name('\array_filter'), $functionCall->getArgs()))->getArrays();
+		$resultTypes = $scope->getType(new FuncCall(new Name('\array_filter'), $functionCall->getArgs()));
+		$resultType = TypeCombinator::union(...array_map(fn ($type) => $type->getIterableValueType(), $resultTypes->getArrays()));
 
-		return TypeCombinator::union(new NullType(), ...array_map(fn ($type) => $type->getIterableValueType(), $resultTypes));
+		return $resultTypes->isIterableAtLeastOnce()->yes() ? $resultType : TypeCombinator::addNull($resultType);
 	}
 
 }

tests/PHPStan/Analyser/nsrt/array-find.php

@@ -24,11 +24,14 @@ function array_find(array $array, callable $callback)
 
 	/**
 	 * @param array<mixed> $array
+	 * @param non-empty-array<mixed> $non_empty_array
 	 */
-	function testMixed(array $array, callable $callback): void
+	function testMixed(array $array, array $non_empty_array, callable $callback): void
 	{
 		assertType('mixed', array_find($array, $callback));
 		assertType('int|null', array_find($array, 'is_int'));
+		assertType('mixed', array_find($non_empty_array, $callback));
+		assertType('int|null', array_find($non_empty_array, 'is_int'));
 	}
 
 	/**
@@ -37,7 +40,20 @@ function testMixed(array $array, callable $callback): void
 	function testConstant(array $array, callable $callback): void
 	{
 		assertType("1|'foo'|DateTime|null", array_find($array, $callback));
-		assertType("1|null", array_find($array, 'is_int'));
+		assertType('1', array_find($array, 'is_int'));
+	}
+
+	/**
+	 * @param array<int> $array
+	 * @param non-empty-array<int> $non_empty_array
+	 */
+	function testInt(array $array, array $non_empty_array, callable $callback): void
+	{
+		assertType('int|null', array_find($array, $callback));
+		assertType('int|null', array_find($array, 'is_int'));
+		assertType('int|null', array_find($non_empty_array, $callback));
+		// should be 'int'
+		assertType('int|null', array_find($non_empty_array, 'is_int'));
 	}
 
 }