From e50ef8bf03c799f826e6fe724308826a954a6d48 Mon Sep 17 00:00:00 2001
From: Matthew Brown <github@muglug.com>
Date: Tue, 8 May 2018 19:49:25 -0400
Subject: [PATCH] Support __invoke return types

---
 .../Expression/Call/FunctionCallChecker.php   | 14 ++++++
 tests/CallableTest.php                        | 47 +++++++++++++++++++
 2 files changed, 61 insertions(+)

diff --git a/src/Psalm/Checker/Statements/Expression/Call/FunctionCallChecker.php b/src/Psalm/Checker/Statements/Expression/Call/FunctionCallChecker.php
index 7fe8605c7..4b27f5c03 100644
--- a/src/Psalm/Checker/Statements/Expression/Call/FunctionCallChecker.php
+++ b/src/Psalm/Checker/Statements/Expression/Call/FunctionCallChecker.php
@@ -140,6 +140,20 @@ class FunctionCallChecker extends \Psalm\Checker\Statements\Expression\CallCheck
                         ) === false) {
                             return false;
                         }
+
+                        $invokable_return_type = $codebase->methods->getMethodReturnType(
+                            $var_type_part->value . '::__invoke',
+                            $var_type_part->value
+                        );
+
+                        if (isset($stmt->inferredType)) {
+                            $stmt->inferredType = Type::combineUnionTypes(
+                                $invokable_return_type ?: Type::getMixed(),
+                                $stmt->inferredType
+                            );
+                        } else {
+                            $stmt->inferredType = $invokable_return_type ?: Type::getMixed();
+                        }
                     }
                 }
 
diff --git a/tests/CallableTest.php b/tests/CallableTest.php
index 5e5a8438b..3587d0da1 100644
--- a/tests/CallableTest.php
+++ b/tests/CallableTest.php
@@ -485,6 +485,53 @@ class CallableTest extends TestCase
                     function doSomething($p): void {}
                     doSomething(function(): bool { return false; });',
             ],
+            'callableProperties' => [
+                '<?php
+                    class C {
+                        /** @psalm-var callable():bool */
+                        private $callable;
+
+                        /**
+                         * @psalm-param callable():bool $callable
+                         */
+                        public function __construct(callable $callable) {
+                            $this->callable = $callable;
+                        }
+
+                        public function callTheCallableDirectly(): bool {
+                            return ($this->callable)();
+                        }
+
+                        public function callTheCallableIndirectly(): bool {
+                            $r = $this->callable;
+                            return $r();
+                        }
+                    }',
+            ],
+            'invokableProperties' => [
+                '<?php
+                    class A {
+                        public function __invoke(): bool { return true; }
+                    }
+
+                    class C {
+                        /** @var A $invokable */
+                        private $invokable;
+
+                        public function __construct(A $invokable) {
+                            $this->invokable = $invokable;
+                        }
+
+                        public function callTheInvokableDirectly(): bool {
+                            return ($this->invokable)();
+                        }
+
+                        public function callTheInvokableIndirectly(): bool {
+                            $r = $this->invokable;
+                            return $r();
+                        }
+                    }',
+            ]
         ];
     }