Resolve nested upper bounds correctly

klimick · May 8, 2024 · 361370c · 361370c
1 parent 40156a4
commit 361370c
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Showing 2 changed files with 62 additions and 0 deletions.
diff --git a/src/Psalm/Internal/Type/TemplateStandinTypeReplacer.php b/src/Psalm/Internal/Type/TemplateStandinTypeReplacer.php
@@ -895,6 +895,31 @@ private static function handleTemplateParamStandin(
         }
 
         if ($add_lower_bound && $input_type && !$template_result->readonly) {
+            $replacement_type = TypeExpander::expandUnion(
+                $codebase,
+                $replacement_type,
+                $calling_class,
+                $calling_class,
+                null,
+            );
+
+            if ($depth < 10) {
+                $replacement_type = self::replace(
+                    $replacement_type,
+                    $template_result,
+                    $codebase,
+                    $statements_analyzer,
+                    $input_type,
+                    $input_arg_offset,
+                    $calling_class,
+                    $calling_function,
+                    true,
+                    true,
+                    $bound_equality_classlike,
+                    $depth + 1,
+                );
+            }
+
             $matching_input_keys = [];
 
             if (UnionTypeComparator::canBeContainedBy(

diff --git a/tests/ClosureTest.php b/tests/ClosureTest.php
@@ -17,6 +17,43 @@ class ClosureTest extends TestCase
     public function providerValidCodeParse(): iterable
     {
         return [
+            'resolveNestedUpperBoundsCorrectly' => [
+                'code' => '<?php
+                    /** @template T */
+                    final readonly class Value
+                    {
+                        /** @param T $value */
+                        public function __construct(public mixed $value) {}
+                    }
+
+                    /**
+                     * @template A
+                     * @template B of Value<A>
+                     *
+                     * @param callable(B): B $function
+                     * @return callable(B): B
+                     */
+                    function specializedIdentity(callable $function): callable
+                    {
+                        return $function;
+                    }
+
+                    /**
+                     * @param Value<int> $v
+                     * @return Value<int>
+                     */
+                    function addOne(Value $v): Value
+                    {
+                        return new Value($v->value + 1);
+                    }
+
+                    $fn = specializedIdentity(addOne(...));',
+                'assertions' => [
+                    '$fn' => 'callable(Value<int>):Value<int>',
+                ],
+                'ignored_issues' => [],
+                'php_version' => '8.2',
+            ],
             'byRefUseVar' => [
                 'code' => '<?php
                     $doNotContaminate = 123;