Support unions of scalars in sprintf() arguments

Author: ondrejmirtes

phpstan-baseline.neon

@@ -1487,11 +1487,6 @@ parameters:
 			count: 1
 			path: src/Type/Php/ReflectionMethodConstructorThrowTypeExtension.php
 
-		-
-			message: "#^Doing instanceof PHPStan\\\\Type\\\\ConstantScalarType is error\\-prone and deprecated\\. Use Type\\:\\:isConstantScalarValue\\(\\) or Type\\:\\:getConstantScalarTypes\\(\\) or Type\\:\\:getConstantScalarValues\\(\\) instead\\.$#"
-			count: 1
-			path: src/Type/Php/SprintfFunctionDynamicReturnTypeExtension.php
-
 		-
 			message: "#^Doing instanceof PHPStan\\\\Type\\\\Constant\\\\ConstantStringType is error\\-prone and deprecated\\. Use Type\\:\\:getConstantStrings\\(\\) instead\\.$#"
 			count: 1

src/Type/Php/SprintfFunctionDynamicReturnTypeExtension.php

@@ -5,15 +5,16 @@
 use PhpParser\Node\Expr\FuncCall;
 use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\FunctionReflection;
+use PHPStan\Reflection\InitializerExprTypeResolver;
 use PHPStan\Reflection\ParametersAcceptorSelector;
 use PHPStan\Type\Accessory\AccessoryNonEmptyStringType;
 use PHPStan\Type\Accessory\AccessoryNonFalsyStringType;
 use PHPStan\Type\Accessory\AccessoryNumericStringType;
-use PHPStan\Type\ConstantScalarType;
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\StringType;
 use PHPStan\Type\Type;
+use PHPStan\Type\TypeCombinator;
 use Throwable;
 use function array_key_exists;
 use function array_shift;
@@ -86,29 +87,58 @@ public function getTypeFromFunctionCall(
 		$values = [];
 		foreach ($args as $arg) {
 			$argType = $scope->getType($arg->value);
-			if (!$argType instanceof ConstantScalarType) {
+			if (count($argType->getConstantScalarValues()) === 0) {
 				return $returnType;
 			}
 
-			$values[] = $argType->getValue();
+			$values[] = $argType->getConstantScalarValues();
 		}
 
-		$format = array_shift($values);
-		if (!is_string($format)) {
-			return $returnType;
-		}
+		$combinations = $this->combinations($values);
+		$returnTypes = [];
+		foreach ($combinations as $combination) {
+			$format = array_shift($combination);
+			if (!is_string($format)) {
+				return $returnType;
+			}
 
-		try {
-			if ($functionReflection->getName() === 'sprintf') {
-				$value = @sprintf($format, ...$values);
-			} else {
-				$value = @vsprintf($format, $values);
+			try {
+				if ($functionReflection->getName() === 'sprintf') {
+					$returnTypes[] = $scope->getTypeFromValue(@sprintf($format, ...$combination));
+				} else {
+					$returnTypes[] = $scope->getTypeFromValue(@vsprintf($format, $combination));
+				}
+			} catch (Throwable) {
+				return $returnType;
 			}
-		} catch (Throwable) {
+		}
+
+		if (count($returnTypes) > InitializerExprTypeResolver::CALCULATE_SCALARS_LIMIT) {
 			return $returnType;
 		}
 
-		return $scope->getTypeFromValue($value);
+		return TypeCombinator::union(...$returnTypes);
+	}
+
+	/**
+	 * @param array<mixed> $arrays
+	 * @return iterable<mixed>
+	 */
+	private function combinations(array $arrays): iterable
+	{
+		// from https://stackoverflow.com/a/70800936/565782 by Arnaud Le Blanc
+		if ($arrays === []) {
+			yield [];
+			return;
+		}
+
+		$head = array_shift($arrays);
+
+		foreach ($head as $elem) {
+			foreach ($this->combinations($arrays) as $combination) {
+				yield [$elem, ...$combination];
+			}
+		}
 	}
 
 }

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -193,6 +193,8 @@ public function dataFileAsserts(): iterable
 
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/count-type.php');
 
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/dynamic-sprintf.php');
+
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-2816.php');
 
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-2816-2.php');

tests/PHPStan/Analyser/data/dynamic-sprintf.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace DynamicSprintf;
+
+use function PHPStan\Testing\assertType;
+use function sprintf;
+
+class Foo
+{
+
+	/**
+	 * @param 'a'|'aa' $a
+	 * @param 'b'|'bb' $b
+	 * @param 'c'|'cc' $c
+	 */
+	public function doFoo(string $a, string $b, string $c): void
+	{
+		assertType("'a b c'|'a b cc'|'a bb c'|'a bb cc'|'aa b c'|'aa b cc'|'aa bb c'|'aa bb cc'", sprintf('%s %s %s', $a, $b, $c));
+	}
+
+}