Accept decimal-int-string arguments for %d printf placeholders in strict mode (#5997)

Co-authored-by: VincentLanglet <9052536+VincentLanglet@users.noreply.github.com>

Author: phpstan-bot

src/Rules/Functions/PrintfPlaceholder.php

@@ -3,6 +3,7 @@
 namespace PHPStan\Rules\Functions;
 
 use PHPStan\ShouldNotHappenException;
+use PHPStan\Type\Accessory\AccessoryDecimalIntegerStringType;
 use PHPStan\Type\Accessory\AccessoryNumericStringType;
 use PHPStan\Type\ErrorType;
 use PHPStan\Type\FloatType;
@@ -34,7 +35,11 @@ public function doesArgumentTypeMatchPlaceholder(Type $argumentType, bool $stric
 				return (new IntegerType())->accepts($argumentType, true)->yes();
 			case 'int':
 				return $strictPlaceholderTypes
-					? (new IntegerType())->accepts($argumentType, true)->yes()
+					? (new UnionType([
+						new IntegerType(),
+						// decimal-int-string is allowed because it's printed by %d without any lossy conversion.
+						new IntersectionType([new StringType(), new AccessoryDecimalIntegerStringType()]),
+					]))->accepts($argumentType, true)->yes()
 					: ! $argumentType->toInteger() instanceof ErrorType;
 			case 'float':
 				return $strictPlaceholderTypes

tests/PHPStan/Rules/Functions/PrintfParameterTypeRuleTest.php

@@ -238,6 +238,22 @@ public function testStrict(): void
 				'Parameter #2 of function printf is expected to be string by placeholder #1 ("%s"), true given.',
 				48,
 			],
+			[
+				'Parameter #2 of function printf is expected to be int by placeholder #1 ("%d"), string given.',
+				88,
+			],
+			[
+				'Parameter #2 of function printf is expected to be int by placeholder #1 ("%d"), string given.',
+				90,
+			],
+			[
+				'Parameter #2 of function printf is expected to be int by placeholder #1 ("%d"), string given.',
+				98,
+			],
+			[
+				'Parameter #2 of function printf is expected to be int by placeholder #1 ("%d"), string given.',
+				99,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Functions/data/printf-param-types.php

@@ -70,3 +70,31 @@ public function __toString(): string
 printf('%s %2$*s', 'a', 5, 'a');
 printf('%1$-+\'X10.2f', 5);
 printf('%1$*.*f %s %2$d', 5, 6, new FooStringable()); // 5.000000 foo 6
+
+function testIntString(string $s): void
+{
+	/** @var decimal-int-string $decimalIntString */
+	$decimalIntString = $s;
+	/** @var numeric-string $numericString */
+	$numericString = $s;
+	/** @var non-decimal-int-string $nonDecimalIntString */
+	$nonDecimalIntString = $s;
+
+	// OK: decimal-int-string is printed by %d without lossy conversion
+	printf('%d', $decimalIntString);
+	printf('%f', $decimalIntString);
+
+	// Strict error: numeric-string may contain a decimal part
+	printf('%d', $numericString);
+	// Strict error: non-decimal-int-string may be trimmed/altered by %d
+	printf('%d', $nonDecimalIntString);
+
+	// OK: constant decimal-int-strings
+	printf('%d', '42');
+	printf('%d', '-1');
+	sprintf('%d', '0');
+
+	// Strict error: constant non-decimal-int-strings
+	printf('%d', '00');
+	printf('%d', '+1');
+}