From f67746a2763afcdbbdb2d118fe3bac2f4b7cde7a Mon Sep 17 00:00:00 2001
From: Daniil Gentili <daniil@daniil.it>
Date: Fri, 19 Jan 2024 10:15:49 +0100
Subject: [PATCH] Assert on var of nullsafe expr

---
 .../Statements/Expression/AssertionFinder.php | 23 ++++++++
 tests/MethodCallTest.php                      | 54 +++++++++++++++++++
 2 files changed, 77 insertions(+)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php b/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
index 8c6aaa03ce3..3caf7cf44cd 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
@@ -2085,6 +2085,18 @@ private static function getNullInequalityAssertions(
             $source,
         );
 
+
+        if ($base_conditional instanceof PhpParser\Node\Expr\NullsafeMethodCall) {
+            $vvar_name = ExpressionIdentifier::getExtendedVarId(
+                $base_conditional->var,
+                $this_class_name,
+                $source,
+            );
+            if ($vvar_name !== null) {
+                $if_types[$vvar_name] = [[new IsNotType(new TNull())]];
+            }
+        }
+
         if ($var_name) {
             if ($base_conditional instanceof PhpParser\Node\Expr\Assign) {
                 $var_name = '=' . $var_name;
@@ -2801,6 +2813,17 @@ private static function getNullEqualityAssertions(
             throw new UnexpectedValueException('$null_position value');
         }
 
+        if ($base_conditional instanceof PhpParser\Node\Expr\NullsafeMethodCall) {
+            $vvar_name = ExpressionIdentifier::getExtendedVarId(
+                $base_conditional->var,
+                $this_class_name,
+                $source,
+            );
+            if ($vvar_name !== null) {
+                $if_types[$vvar_name] = [[new IsNotType(new TNull())]];
+            }
+        }
+
         $var_name = ExpressionIdentifier::getExtendedVarId(
             $base_conditional,
             $this_class_name,
diff --git a/tests/MethodCallTest.php b/tests/MethodCallTest.php
index fa56564e790..1d888370947 100644
--- a/tests/MethodCallTest.php
+++ b/tests/MethodCallTest.php
@@ -196,6 +196,60 @@ function printInt(int $int): void {
     public function providerValidCodeParse(): iterable
     {
         return [
+            'nullSafeCallNotNullMakesVarNotNull' => [
+                'code' => '<?php
+                    class Foo {
+                        public function check(): bool {
+                            return false;
+                        }
+                        public function do(): void {}
+                    }
+
+                    /** @var ?Foo */
+                    $foo = null;
+
+                    if ($foo?->check() === null) {
+                        /** @psalm-check-type-exact $foo = null */
+                    }
+
+                    /** @var ?Foo */
+                    $foo = null;
+
+                    if ($foo?->check() !== true) {
+                        /** @psalm-check-type-exact $foo = null */
+                    }
+
+                    /** @var ?Foo */
+                    $foo = null;
+
+                    if ($foo?->check() !== false) {
+                        /** @psalm-check-type-exact $foo = null */
+                    }
+
+                    /** @var ?Foo */
+                    $foo = null;
+
+                    if ($foo?->check() !== null) {
+                        /** @psalm-check-type-exact $foo = Foo */
+                    }
+
+                    /** @var ?Foo */
+                    $foo = null;
+
+                    if ($foo?->check() === false) {
+                        /** @psalm-check-type-exact $foo = Foo */
+                    }
+
+                    /** @var ?Foo */
+                    $foo = null;
+
+                    if ($foo?->check() === true) {
+                        /** @psalm-check-type-exact $foo = Foo */
+                    }',
+                'assertions' => [],
+                'ignored_issues' => [],
+                'php_version' => '8.1'
+            ],
             'notInCallMapTest' => [
                 'code' => '<?php
                     new DOMImplementation();',