From def0489b98f78e395b62912723a9c93d9aac8c24 Mon Sep 17 00:00:00 2001
From: Bruce Weirdan <weirdan@gmail.com>
Date: Sun, 11 Feb 2024 01:47:08 +0100
Subject: [PATCH] Process `@psalm-this-out` on `__construct()` as well

Fixes vimeo/psalm#9649
---
 .../Expression/Call/NewAnalyzer.php           | 48 ++++++++++++++++++-
 tests/ThisOutTest.php                         | 20 ++++++++
 2 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/NewAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/NewAnalyzer.php
index 1dbf40420..db767a303 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/NewAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/NewAnalyzer.php
@@ -11,6 +11,7 @@ use Psalm\Internal\Analyzer\ClassAnalyzer;
 use Psalm\Internal\Analyzer\ClassLikeAnalyzer;
 use Psalm\Internal\Analyzer\FunctionLikeAnalyzer;
 use Psalm\Internal\Analyzer\NamespaceAnalyzer;
+use Psalm\Internal\Analyzer\Statements\Expression\Call\Method\MethodCallReturnTypeFetcher;
 use Psalm\Internal\Analyzer\Statements\Expression\Call\Method\MethodVisibilityAnalyzer;
 use Psalm\Internal\Analyzer\Statements\Expression\CallAnalyzer;
 use Psalm\Internal\Analyzer\Statements\ExpressionAnalyzer;
@@ -21,6 +22,7 @@ use Psalm\Internal\DataFlow\TaintSink;
 use Psalm\Internal\MethodIdentifier;
 use Psalm\Internal\Type\TemplateResult;
 use Psalm\Internal\Type\TemplateStandinTypeReplacer;
+use Psalm\Internal\Type\TypeExpander;
 use Psalm\Issue\AbstractInstantiation;
 use Psalm\Issue\DeprecatedClass;
 use Psalm\Issue\ImpureMethodCall;
@@ -58,6 +60,7 @@ use Psalm\Type\Union;
 
 use function array_map;
 use function array_values;
+use function count;
 use function in_array;
 use function md5;
 use function preg_match;
@@ -429,6 +432,8 @@ final class NewAnalyzer extends CallAnalyzer
 
             $declaring_method_id = $codebase->methods->getDeclaringMethodId($method_id);
 
+            $method_storage = null;
+
             if ($declaring_method_id) {
                 $method_storage = $codebase->methods->getStorage($declaring_method_id);
 
@@ -500,6 +505,7 @@ final class NewAnalyzer extends CallAnalyzer
             }
 
             $generic_param_types = null;
+            $self_out_candidate = null;
 
             if ($storage->template_types) {
                 foreach ($storage->template_types as $template_name => $base_type) {
@@ -537,9 +543,49 @@ final class NewAnalyzer extends CallAnalyzer
                         'had_template' => true,
                     ]);
                 }
+
+                if ($method_storage && $method_storage->self_out_type) {
+                    $self_out_candidate = $method_storage->self_out_type;
+
+                    if ($template_result->lower_bounds) {
+                        $self_out_candidate = TypeExpander::expandUnion(
+                            $codebase,
+                            $self_out_candidate,
+                            $fq_class_name,
+                            null,
+                            $storage->parent_class,
+                            true,
+                            false,
+                            false,
+                            true,
+                        );
+                    }
+
+                    $self_out_candidate = MethodCallReturnTypeFetcher::replaceTemplateTypes(
+                        $self_out_candidate,
+                        $template_result,
+                        $method_id,
+                        count($stmt->getArgs()),
+                        $codebase,
+                    );
+
+                    $self_out_candidate = TypeExpander::expandUnion(
+                        $codebase,
+                        $self_out_candidate,
+                        $fq_class_name,
+                        $fq_class_name,
+                        $storage->parent_class,
+                        true,
+                        false,
+                        false,
+                        true,
+                    );
+                    $statements_analyzer->node_data->setType($stmt, $self_out_candidate);
+                }
             }
 
-            if ($generic_param_types) {
+            // XXX: what if we need both?
+            if ($generic_param_types && !$self_out_candidate) {
                 $result_atomic_type = new TGenericObject(
                     $fq_class_name,
                     $generic_param_types,
diff --git a/tests/ThisOutTest.php b/tests/ThisOutTest.php
index a537996ae..1deb83342 100644
--- a/tests/ThisOutTest.php
+++ b/tests/ThisOutTest.php
@@ -84,6 +84,26 @@ class ThisOutTest extends TestCase
                     '$data3===' => 'list<2|3>',
                 ],
             ],
+            'provideDefaultTypeToTypeArguments' => [
+                'code' => <<<'PHP'
+                <?php
+                    /** @template T of 'idle'|'running' */
+                    class App {
+                        /** @psalm-this-out self<'idle'> */
+                        public function __construct() {}
+
+                        /**
+                         * @psalm-if-this-is self<'idle'>
+                         * @psalm-this-out self<'running'>
+                         */
+                        public function start(): void {}
+                    }
+                    $app = new App();
+                PHP,
+                'assertions' => [
+                    '$app===' => "App<'idle'>",
+                ],
+            ],
         ];
     }
 }