Fix

Author: ondrejmirtes

src/Type/Generic/TemplateTypeTrait.php

@@ -92,7 +92,7 @@ public function equals(Type $type): bool
 		return $type instanceof self
 			&& $type->scope->equals($this->scope)
 			&& $type->name === $this->name
-			&& $this->bound->equals($type);
+			&& $this->bound->equals($type->bound);
 	}
 
 	public function isAcceptedBy(Type $acceptingType, bool $strictTypes): TrinaryLogic

tests/PHPStan/Rules/Methods/ReturnTypeRuleTest.php

@@ -444,4 +444,9 @@ public function testBug4590(): void
 		]);
 	}
 
+	public function testTemplateStringBound(): void
+	{
+		$this->analyse([__DIR__ . '/data/template-string-bound.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Methods/data/template-string-bound.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace TemplateStringBound;
+
+/** @template T of string */
+class Foo
+{
+
+	/** @var T */
+	private $value;
+
+	/**
+	 * @param T $value
+	 */
+	public function __construct($value)
+	{
+		$this->value = $value;
+	}
+
+	/**
+	 * @return T
+	 */
+	public function getValue(): string
+	{
+		return $this->value;
+	}
+
+}
+
+/** @template T of int */
+class Bar
+{
+
+	/** @var T */
+	private $value;
+
+	/**
+	 * @param T $value
+	 */
+	public function __construct($value)
+	{
+		$this->value = $value;
+	}
+
+	/**
+	 * @return T
+	 */
+	public function getValue(): int
+	{
+		return $this->value;
+	}
+
+}

tests/PHPStan/Type/StringTypeTest.php

@@ -162,7 +162,7 @@ public function dataAccepts(): iterable
 				new StringType(),
 				TemplateTypeVariance::createInvariant()
 			)->toArgument(),
-			TrinaryLogic::createNo(),
+			TrinaryLogic::createYes(),
 		];
 	}