Expand object-with-properties

Fixes #4057

src/Psalm/Internal/Type/TypeExpander.php

@@ -414,6 +414,21 @@ class TypeExpander
             );
         }
 
+        if ($return_type instanceof Type\Atomic\TObjectWithProperties) {
+            foreach ($return_type->properties as &$property_type) {
+                $property_type = self::expandUnion(
+                    $codebase,
+                    $property_type,
+                    $self_class,
+                    $static_class_type,
+                    $parent_class,
+                    $evaluate_class_constants,
+                    $evaluate_conditional_types,
+                    $final
+                );
+            }
+        }
+
         if ($return_type instanceof Type\Atomic\TCallable
             || $return_type instanceof Type\Atomic\TFn
         ) {

tests/TypeAnnotationTest.php

@@ -315,7 +315,27 @@ class TypeAnnotationTest extends TestCase
                         echo $elt["p1"];
                     }
                 }'
-            ]
+            ],
+            'objectWithPropertiesAlias' => [
+                '<?php
+                    /**
+                     * @psalm-type FooStruct=string
+                     */
+                    class A {}
+
+                    /**
+                     * @psalm-import-type FooStruct from A as F2
+                     */
+                    class B {
+                        /**
+                         * @param object{foo: F2} $a
+                         * @return object{foo: string}
+                         */
+                        public function bar($a) {
+                            return $a;
+                        }
+                    }'
+            ],
         ];
     }