Improve decimal integer string inferences

Author: VincentLanglet

src/Reflection/InitializerExprTypeResolver.php

@@ -45,6 +45,7 @@
 use PHPStan\ShouldNotHappenException;
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\Accessory\AccessoryArrayListType;
+use PHPStan\Type\Accessory\AccessoryDecimalIntegerStringType;
 use PHPStan\Type\Accessory\AccessoryLiteralStringType;
 use PHPStan\Type\Accessory\AccessoryLowercaseStringType;
 use PHPStan\Type\Accessory\AccessoryNonEmptyStringType;
@@ -591,33 +592,41 @@ public function resolveConcatType(Type $left, Type $right): Type
 			$accessoryTypes[] = new AccessoryUppercaseStringType();
 		}
 
-		$leftNumericStringNonEmpty = TypeCombinator::remove($leftStringType, new ConstantStringType(''));
-		if ($leftNumericStringNonEmpty->isNumericString()->yes()) {
-			$validationCallback = $left->isInteger()->yes()
-				? static fn (string $value): bool => !str_starts_with($value, '-')
-				: static fn (string $value): bool => Strings::match($value, '#^\d+$#') !== null;
+		$leftStringNonEmpty = TypeCombinator::remove($leftStringType, new ConstantStringType(''));
+		$rightStringNonEmpty = TypeCombinator::remove($leftStringType, new ConstantStringType(''));
+		if (
+			$leftStringNonEmpty->isDecimalIntegerString()->and($rightStringNonEmpty->isDecimalIntegerString())->yes()
+			&& $leftStringNonEmpty->isSuperTypeOf(new ConstantStringType('0'))->no()
+		) {
+			$accessoryTypes[] = new AccessoryDecimalIntegerStringType();
+		} else {
+			if ($leftStringNonEmpty->isNumericString()->yes()) {
+				$validationCallback = $left->isInteger()->yes()
+					? static fn (string $value): bool => !str_starts_with($value, '-')
+					: static fn (string $value): bool => Strings::match($value, '#^\d+$#') !== null;
 
-			$allRightConstantsZeroOrMore = false;
-			foreach ($rightConstantStrings as $rightConstantString) {
-				if ($rightConstantString->getValue() === '') {
-					continue;
-				}
+				$allRightConstantsZeroOrMore = false;
+				foreach ($rightConstantStrings as $rightConstantString) {
+					if ($rightConstantString->getValue() === '') {
+						continue;
+					}
 
-				if (
-					!is_numeric($rightConstantString->getValue())
-					|| !$validationCallback($rightConstantString->getValue())
-				) {
-					$allRightConstantsZeroOrMore = false;
-					break;
-				}
+					if (
+						!is_numeric($rightConstantString->getValue())
+						|| !$validationCallback($rightConstantString->getValue())
+					) {
+						$allRightConstantsZeroOrMore = false;
+						break;
+					}
 
-				$allRightConstantsZeroOrMore = true;
-			}
+					$allRightConstantsZeroOrMore = true;
+				}
 
-			$zeroOrMoreInteger = IntegerRangeType::fromInterval(0, null);
-			$nonNegativeRight = $allRightConstantsZeroOrMore || $zeroOrMoreInteger->isSuperTypeOf($right)->yes();
-			if ($nonNegativeRight) {
-				$accessoryTypes[] = new AccessoryNumericStringType();
+				$zeroOrMoreInteger = IntegerRangeType::fromInterval(0, null);
+				$nonNegativeRight = $allRightConstantsZeroOrMore || $zeroOrMoreInteger->isSuperTypeOf($right)->yes();
+				if ($nonNegativeRight) {
+					$accessoryTypes[] = new AccessoryNumericStringType();
+				}
 			}
 		}
 

src/Type/Constant/ConstantStringType.php

@@ -19,6 +19,7 @@
 use PHPStan\Reflection\TrivialParametersAcceptor;
 use PHPStan\ShouldNotHappenException;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Accessory\AccessoryDecimalIntegerStringType;
 use PHPStan\Type\Accessory\AccessoryLiteralStringType;
 use PHPStan\Type\Accessory\AccessoryLowercaseStringType;
 use PHPStan\Type\Accessory\AccessoryNonEmptyStringType;
@@ -459,7 +460,9 @@ public function generalize(GeneralizePrecision $precision): Type
 				new AccessoryLiteralStringType(),
 			];
 
-			if (is_numeric($this->getValue())) {
+			if ((string) (int) $this->getValue() === $this->getValue()) {
+				$accessories[] = new AccessoryDecimalIntegerStringType();
+			} elseif (is_numeric($this->getValue())) {
 				$accessories[] = new AccessoryNumericStringType();
 			}
 

src/Type/IntegerRangeType.php

@@ -10,9 +10,9 @@
 use PHPStan\PhpDocParser\Ast\Type\TypeNode;
 use PHPStan\Reflection\InitializerExprTypeResolver;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Accessory\AccessoryDecimalIntegerStringType;
 use PHPStan\Type\Accessory\AccessoryLowercaseStringType;
 use PHPStan\Type\Accessory\AccessoryNonFalsyStringType;
-use PHPStan\Type\Accessory\AccessoryNumericStringType;
 use PHPStan\Type\Accessory\AccessoryUppercaseStringType;
 use PHPStan\Type\Constant\ConstantBooleanType;
 use PHPStan\Type\Constant\ConstantIntegerType;
@@ -509,7 +509,7 @@ public function toString(): Type
 				new StringType(),
 				new AccessoryLowercaseStringType(),
 				new AccessoryUppercaseStringType(),
-				new AccessoryNumericStringType(),
+				new AccessoryDecimalIntegerStringType(),
 				new AccessoryNonFalsyStringType(),
 			]);
 		}
@@ -518,7 +518,7 @@ public function toString(): Type
 			new StringType(),
 			new AccessoryLowercaseStringType(),
 			new AccessoryUppercaseStringType(),
-			new AccessoryNumericStringType(),
+			new AccessoryDecimalIntegerStringType(),
 		]);
 	}
 

src/Type/IntegerType.php

@@ -6,8 +6,8 @@
 use PHPStan\PhpDocParser\Ast\Type\IdentifierTypeNode;
 use PHPStan\PhpDocParser\Ast\Type\TypeNode;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Accessory\AccessoryDecimalIntegerStringType;
 use PHPStan\Type\Accessory\AccessoryLowercaseStringType;
-use PHPStan\Type\Accessory\AccessoryNumericStringType;
 use PHPStan\Type\Accessory\AccessoryUppercaseStringType;
 use PHPStan\Type\Constant\ConstantArrayType;
 use PHPStan\Type\Constant\ConstantBooleanType;
@@ -78,7 +78,7 @@ public function toString(): Type
 			new StringType(),
 			new AccessoryLowercaseStringType(),
 			new AccessoryUppercaseStringType(),
-			new AccessoryNumericStringType(),
+			new AccessoryDecimalIntegerStringType(),
 		]);
 	}