Support float as template type bound

Author: ondrejmirtes

src/Rules/Generics/TemplateTypeCheck.php

@@ -8,6 +8,7 @@
 use PHPStan\Rules\ClassNameNodePair;
 use PHPStan\Rules\RuleErrorBuilder;
 use PHPStan\Type\BooleanType;
+use PHPStan\Type\FloatType;
 use PHPStan\Type\Generic\GenericObjectType;
 use PHPStan\Type\Generic\TemplateType;
 use PHPStan\Type\Generic\TemplateTypeScope;
@@ -111,6 +112,7 @@ public function check(
 					$boundClass === MixedType::class
 					|| $boundClass === StringType::class
 					|| $boundClass === IntegerType::class
+					|| $boundClass === FloatType::class
 					|| $boundClass === BooleanType::class
 					|| $boundClass === ObjectWithoutClassType::class
 					|| $boundClass === ObjectType::class

src/Type/Generic/TemplateFloatType.php

@@ -0,0 +1,54 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type\Generic;
+
+use PHPStan\Type\FloatType;
+use PHPStan\Type\Traits\UndecidedComparisonCompoundTypeTrait;
+use PHPStan\Type\Type;
+
+/** @api */
+final class TemplateFloatType extends FloatType implements TemplateType
+{
+
+	/** @use TemplateTypeTrait<FloatType> */
+	use TemplateTypeTrait;
+	use UndecidedComparisonCompoundTypeTrait;
+
+	public function __construct(
+		TemplateTypeScope $scope,
+		TemplateTypeStrategy $templateTypeStrategy,
+		TemplateTypeVariance $templateTypeVariance,
+		string $name,
+		FloatType $bound
+	)
+	{
+		parent::__construct();
+		$this->scope = $scope;
+		$this->strategy = $templateTypeStrategy;
+		$this->variance = $templateTypeVariance;
+		$this->name = $name;
+		$this->bound = $bound;
+	}
+
+	public function traverse(callable $cb): Type
+	{
+		$newBound = $cb($this->getBound());
+		if ($this->getBound() !== $newBound && $newBound instanceof FloatType) {
+			return new self(
+				$this->scope,
+				$this->strategy,
+				$this->variance,
+				$this->name,
+				$newBound
+			);
+		}
+
+		return $this;
+	}
+
+	protected function shouldGeneralizeInferredType(): bool
+	{
+		return false;
+	}
+
+}

src/Type/Generic/TemplateTypeFactory.php

@@ -5,6 +5,7 @@
 use PHPStan\PhpDoc\Tag\TemplateTag;
 use PHPStan\Type\BenevolentUnionType;
 use PHPStan\Type\BooleanType;
+use PHPStan\Type\FloatType;
 use PHPStan\Type\IntegerType;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\ObjectType;
@@ -45,6 +46,10 @@ public static function create(TemplateTypeScope $scope, string $name, ?Type $bou
 			return new TemplateIntegerType($scope, $strategy, $variance, $name, $bound);
 		}
 
+		if ($bound instanceof FloatType && ($boundClass === FloatType::class || $bound instanceof TemplateType)) {
+			return new TemplateFloatType($scope, $strategy, $variance, $name, $bound);
+		}
+
 		if ($bound instanceof BooleanType && ($boundClass === BooleanType::class || $bound instanceof TemplateType)) {
 			return new TemplateBooleanType($scope, $strategy, $variance, $name, $bound);
 		}

tests/PHPStan/Analyser/data/generics.php

@@ -1422,3 +1422,18 @@ function (bool $b): void {
 	assertType('false', boolBound(false));
 	assertType('bool', boolBound($b));
 };
+
+/**
+ * @template T of float
+ * @param T $f
+ * @return T
+ */
+function floatBound(float $f): float
+{
+	return $f;
+}
+
+function (float $f): void {
+	assertType('1.0', floatBound(1.0));
+	assertType('float', floatBound($f));
+};

tests/PHPStan/Rules/Generics/ClassTemplateTypeRuleTest.php

@@ -41,10 +41,6 @@ public function testRule(): void
 				'PHPDoc tag @template T for class ClassTemplateType\Bar has invalid bound type ClassTemplateType\Zazzzu.',
 				16,
 			],
-			[
-				'PHPDoc tag @template T for class ClassTemplateType\Baz with bound type float is not supported.',
-				24,
-			],
 			[
 				'Class ClassTemplateType\Baz referenced with incorrect case: ClassTemplateType\baz.',
 				32,
@@ -69,10 +65,6 @@ public function testRule(): void
 				'PHPDoc tag @template T for anonymous class has invalid bound type ClassTemplateType\Zazzzu.',
 				63,
 			],
-			[
-				'PHPDoc tag @template T for anonymous class with bound type float is not supported.',
-				68,
-			],
 			[
 				'Class ClassTemplateType\Baz referenced with incorrect case: ClassTemplateType\baz.',
 				73,

tests/PHPStan/Rules/Generics/FunctionTemplateTypeRuleTest.php

@@ -35,14 +35,14 @@ public function testRule(): void
 				'PHPDoc tag @template T for function FunctionTemplateType\bar() has invalid bound type FunctionTemplateType\Zazzzu.',
 				16,
 			],
-			[
-				'PHPDoc tag @template T for function FunctionTemplateType\baz() with bound type float is not supported.',
-				24,
-			],
 			[
 				'PHPDoc tag @template for function FunctionTemplateType\lorem() cannot have existing type alias TypeAlias as its name.',
 				32,
 			],
+			[
+				'PHPDoc tag @template T for function FunctionTemplateType\resourceBound() with bound type resource is not supported.',
+				50,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Generics/InterfaceTemplateTypeRuleTest.php

@@ -37,10 +37,6 @@ public function testRule(): void
 				'PHPDoc tag @template T for interface InterfaceTemplateType\Bar has invalid bound type InterfaceTemplateType\Zazzzu.',
 				16,
 			],
-			[
-				'PHPDoc tag @template T for interface InterfaceTemplateType\Baz with bound type float is not supported.',
-				24,
-			],
 			[
 				'PHPDoc tag @template for interface InterfaceTemplateType\Lorem cannot have existing type alias TypeAlias as its name.',
 				33,

tests/PHPStan/Rules/Generics/MethodTemplateTypeRuleTest.php

@@ -41,10 +41,6 @@ public function testRule(): void
 				'PHPDoc tag @template T for method MethodTemplateType\Bar::doFoo() shadows @template T of Exception for class MethodTemplateType\Bar.',
 				37,
 			],
-			[
-				'PHPDoc tag @template T for method MethodTemplateType\Baz::doFoo() with bound type float is not supported.',
-				50,
-			],
 			[
 				'PHPDoc tag @template for method MethodTemplateType\Lorem::doFoo() cannot have existing type alias TypeAlias as its name.',
 				66,

tests/PHPStan/Rules/Generics/TraitTemplateTypeRuleTest.php

@@ -37,10 +37,6 @@ public function testRule(): void
 				'PHPDoc tag @template T for trait TraitTemplateType\Bar has invalid bound type TraitTemplateType\Zazzzu.',
 				16,
 			],
-			[
-				'PHPDoc tag @template T for trait TraitTemplateType\Baz with bound type float is not supported.',
-				24,
-			],
 			[
 				'PHPDoc tag @template for trait TraitTemplateType\Lorem cannot have existing type alias TypeAlias as its name.',
 				33,

tests/PHPStan/Rules/Generics/data/function-template.php

@@ -39,3 +39,15 @@ function ipsum()
 {
 
 }
+
+/** @template T of float */
+function dolor()
+{
+
+}
+
+/** @template T of resource */
+function resourceBound()
+{
+
+}