General array after offset assign is non empty

Author: ondrejmirtes

src/Analyser/MutatingScope.php

@@ -3622,7 +3622,7 @@ private static function generalizeType(Type $a, Type $b): Type
 $constantArrays[$key][] = $type;
 continue;
 }
-if ($type instanceof ArrayType) {
+if ($type->isArray()->yes()) {
 $generalArrays[$key][] = $type;
 continue;
 }

src/Rules/Missing/MissingClosureNativeReturnTypehintRule.php

@@ -7,7 +7,6 @@
 use PHPStan\Node\ClosureReturnStatementsNode;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
-use PHPStan\Type\ArrayType;
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\NeverType;
@@ -115,7 +114,7 @@ public function processNode(Node $node, Scope $scope): array
 
 $returnType = TypeUtils::generalizeType($returnType);
 $description = $returnType->describe(VerbosityLevel::typeOnly());
-if ($returnType instanceof ArrayType) {
+if ($returnType->isArray()->yes()) {
 $description = 'array';
 }
 if ($hasNull) {

src/Type/ArrayType.php

@@ -5,6 +5,7 @@
 use PHPStan\Reflection\ClassMemberAccessAnswerer;
 use PHPStan\Reflection\TrivialParametersAcceptor;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Accessory\NonEmptyArrayType;
 use PHPStan\Type\Constant\ConstantArrayType;
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
@@ -225,10 +226,10 @@ public function setOffsetValueType(?Type $offsetType, Type $valueType, bool $uni
 $offsetType = new IntegerType();
 }
 
-return new self(
+return TypeCombinator::intersect(new self(
 TypeCombinator::union($this->keyType, self::castToArrayKeyType($offsetType)),
 $unionValues ? TypeCombinator::union($this->itemType, $valueType) : $valueType
-);
+), new NonEmptyArrayType());
 }
 
 public function isCallable(): TrinaryLogic

src/Type/BenevolentUnionType.php

@@ -41,4 +41,24 @@ public function isAcceptedBy(Type $acceptingType, bool $strictTypes): TrinaryLog
 return TrinaryLogic::createNo()->or(...$results);
 }
 
+public function traverse(callable $cb): Type
+{
+$types = [];
+$changed = false;
+
+foreach ($this->getTypes() as $type) {
+$newType = $cb($type);
+if ($type !== $newType) {
+$changed = true;
+}
+$types[] = $newType;
+}
+
+if ($changed) {
+return TypeUtils::toBenevolentUnion(TypeCombinator::union(...$types));
+}
+
+return $this;
+}
+
 }

src/Type/Constant/ConstantArrayType.php

@@ -7,6 +7,7 @@
 use PHPStan\Reflection\InaccessibleMethod;
 use PHPStan\Reflection\TrivialParametersAcceptor;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Accessory\NonEmptyArrayType;
 use PHPStan\Type\ArrayType;
 use PHPStan\Type\BooleanType;
 use PHPStan\Type\CompoundType;
@@ -477,12 +478,31 @@ public function unsetOffset(Type $offsetType): Type
 }
 }
 
-return $this->generalize();
+$arrays = [];
+foreach ($this->getAllArrays() as $tmp) {
+$arrays[] = new self($tmp->keyTypes, $tmp->valueTypes, $tmp->nextAutoIndex, array_keys($tmp->keyTypes));
+}
+
+return TypeUtils::generalizeType(TypeCombinator::union(...$arrays));
 }
 
 public function isIterableAtLeastOnce(): TrinaryLogic
 {
-return TrinaryLogic::createFromBoolean(count($this->keyTypes) > 0);
+$keysCount = count($this->keyTypes);
+if ($keysCount === 0) {
+return TrinaryLogic::createNo();
+}
+
+$optionalKeysCount = count($this->optionalKeys);
+if ($optionalKeysCount === 0) {
+return TrinaryLogic::createYes();
+}
+
+if ($optionalKeysCount < $keysCount) {
+return TrinaryLogic::createYes();
+}
+
+return TrinaryLogic::createMaybe();
 }
 
 public function removeLast(): self
@@ -583,10 +603,16 @@ public function generalize(): Type
 return $this;
 }
 
-return new ArrayType(
+$arrayType = new ArrayType(
 TypeUtils::generalizeType($this->getKeyType()),
 $this->getItemType()
 );
+
+if (count($this->keyTypes) > count($this->optionalKeys)) {
+return TypeCombinator::intersect($arrayType, new NonEmptyArrayType());
+}
+
+return $arrayType;
 }
 
 /**

src/Type/Php/ArrayFilterFunctionReturnTypeReturnTypeExtension.php

@@ -12,6 +12,7 @@
 use PHPStan\Type\ArrayType;
 use PHPStan\Type\BenevolentUnionType;
 use PHPStan\Type\Constant\ConstantArrayType;
+use PHPStan\Type\Constant\ConstantArrayTypeBuilder;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\NeverType;
 use PHPStan\Type\NullType;
@@ -84,22 +85,19 @@ public function removeFalsey(Type $type): Type
 $keys = $type->getKeyTypes();
 $values = $type->getValueTypes();
 
-$generalize = false;
+$builder = ConstantArrayTypeBuilder::createEmpty();
 
 foreach ($values as $offset => $value) {
 $isFalsey = $falseyTypes->isSuperTypeOf($value);
 
-if ($isFalsey->yes()) {
-unset($keys[$offset], $values[$offset]);
-} elseif ($isFalsey->maybe()) {
-$values[$offset] = TypeCombinator::remove($values[$offset], $falseyTypes);
-$generalize = true;
+if ($isFalsey->maybe()) {
+$builder->setOffsetValueType($keys[$offset], TypeCombinator::remove($value, $falseyTypes), true);
+} elseif ($isFalsey->no()) {
+$builder->setOffsetValueType($keys[$offset], $value);
 }
 }
 
-$filteredArray = new ConstantArrayType(array_values($keys), array_values($values));
-
-return $generalize ? $filteredArray->generalize() : $filteredArray;
+return $builder->getArray();
 }
 
 $keyType = $type->getIterableKeyType();

src/Type/TypeUtils.php

@@ -120,15 +120,13 @@ public static function getAnyArrays(Type $type): array
 
 public static function generalizeType(Type $type): Type
 {
-if ($type instanceof ConstantType) {
-return $type->generalize();
-} elseif ($type instanceof UnionType) {
-return TypeCombinator::union(...array_map(static function (Type $innerType): Type {
-return self::generalizeType($innerType);
-}, $type->getTypes()));
-}
+return TypeTraverser::map($type, static function (Type $type, callable $traverse): Type {
+if ($type instanceof ConstantType) {
+return $type->generalize();
+}
 
-return $type;
+return $traverse($type);
+});
 }
 
 /**

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -3194,6 +3194,10 @@ public function dataBinaryOperations(): array
 'array<int, 1|2|3>',
 '$arrayToBeUnset',
 ],
+[
+'array<int, 1|2|3>',
+'$arrayToBeUnset2',
+],
 [
 'array',
 '$shiftedNonEmptyArray',
@@ -5036,7 +5040,7 @@ public function dataArrayFunctions(): array
 'array_intersect_key(...[$integers, [4, 5, 6]])',
 ],
 [
-'array<int|string, int>',
+'array<int>',
 'array_intersect_key(...$generalIntegersInAnotherArray, [])',
 ],
 [
@@ -5128,7 +5132,7 @@ public function dataArrayFunctions(): array
 'array_merge(...[$generalStringKeys, $generalDateTimeValues])',
 ],
 [
-'array<int|string, int>',
+'array<int>',
 '$mergedInts',
 ],
 [
@@ -5244,7 +5248,7 @@ public function dataArrayFunctions(): array
 'array_filter($union)',
 ],
 [
-'array<int, int<min, -1>|int<1, max>|true>',
+'array(?0 => true, ?1 => int<min, -1>|int<1, max>)',
 'array_filter($withPossiblyFalsey)',
 ],
 [
@@ -7545,7 +7549,7 @@ public function dataForeachLoopVariables(): array
 "'end'",
 ],
 [
-'array<int, 1|2|3>',
+'array<int, 1|2|3>&nonEmpty',
 '$integers',
 "'end'",
 ],
@@ -7560,7 +7564,7 @@ public function dataForeachLoopVariables(): array
 "'begin'",
 ],
 [
-'array<string, 1|2|3>',
+'array<string, 1|2|3>&nonEmpty',
 '$this->property',
 "'end'",
 ],
@@ -9642,7 +9646,7 @@ public function dataGeneralizeScope(): array
 {
 return [
 [
-"array<int|string, array<int|string, array('hitCount' => int, 'loadCount' => int, 'removeCount' => int, 'saveCount' => int)>>",
+"array<array<int|string, array('hitCount' => int, 'loadCount' => int, 'removeCount' => int, 'saveCount' => int)>>",
 '$statistics',
 ],
 ];
@@ -9669,7 +9673,7 @@ public function dataGeneralizeScopeRecursiveType(): array
 {
 return [
 [
-'array()|array(\'foo\' => array<int|string, array>)',
+'array()|array(\'foo\' => array<array>)',
 '$data',
 ],
 ];
@@ -10250,6 +10254,11 @@ public function dataBug3997(): array
 return $this->gatherAssertTypes(__DIR__ . '/data/bug-3997.php');
 }
 
+public function dataBug4016(): array
+{
+return $this->gatherAssertTypes(__DIR__ . '/data/bug-4016.php');
+}
+
 /**
  * @dataProvider dataBug2574
  * @dataProvider dataBug2577
@@ -10341,6 +10350,7 @@ public function dataBug3997(): array
  * @dataProvider dataBug3990
  * @dataProvider dataBug3991
  * @dataProvider dataBug3993
+ * @dataProvider dataBug4016
  * @param string $assertType
  * @param string $file
  * @param mixed ...$args

tests/PHPStan/Analyser/data/assign-nested-arrays.php

@@ -14,7 +14,7 @@ public function doFoo(int $i)
 $array[$i]['bar'] = 1;
 $array[$i]['baz'] = 2;
 
-assertType('array<int, array(\'bar\' => 1, \'baz\' => 2)>', $array);
+assertType('array<int, array(\'bar\' => 1, \'baz\' => 2)>&nonEmpty', $array);
 }
 
 public function doBar(int $i, int $j)
@@ -27,7 +27,7 @@ public function doBar(int $i, int $j)
 echo $array[$i][$j]['bar'];
 echo $array[$i][$j]['baz'];
 
-assertType('array<int, array<int, array(\'bar\' => 1, \'baz\' => 2)>>', $array);
+assertType('array<int, array<int, array(\'bar\' => 1, \'baz\' => 2)>&nonEmpty>&nonEmpty', $array);
 }
 
 }

tests/PHPStan/Analyser/data/binary.php

@@ -134,6 +134,9 @@ public function doFoo(array $generalArray)
 $arrayToBeUnset = $array;
 unset($arrayToBeUnset[$string]);
 
+$arrayToBeUnset2 = $arrayToBeUnset;
+unset($arrayToBeUnset2[$string]);
+
 /** @var array $shiftedNonEmptyArray */
 $shiftedNonEmptyArray = doFoo();