From a1549329064cbc80eca26e34d50efbfd69990631 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tinjo=20Sch=C3=B6ni?=
 <32767367+tscni@users.noreply.github.com>
Date: Sat, 24 Jun 2023 04:38:48 +0200
Subject: [PATCH] Consider a property type change as a signature change

---
 .../Internal/Diff/ClassStatementsDiffer.php   | 16 ++++++
 tests/FileDiffTest.php                        | 57 +++++++++++++++++++
 2 files changed, 73 insertions(+)

diff --git a/src/Psalm/Internal/Diff/ClassStatementsDiffer.php b/src/Psalm/Internal/Diff/ClassStatementsDiffer.php
index 686aeb92917..7d465837683 100644
--- a/src/Psalm/Internal/Diff/ClassStatementsDiffer.php
+++ b/src/Psalm/Internal/Diff/ClassStatementsDiffer.php
@@ -158,6 +158,22 @@ static function (
                         return false;
                     }
 
+                    if ($a->type xor $b->type) {
+                        return false;
+                    }
+
+                    if ($a->type) {
+                        $a_type_start = (int) $a->type->getAttribute('startFilePos');
+                        $a_type_end = (int) $a->type->getAttribute('endFilePos');
+                        $b_type_start = (int) $b->type->getAttribute('startFilePos');
+                        $b_type_end = (int) $b->type->getAttribute('endFilePos');
+                        if (substr($a_code, $a_type_start, $a_type_end - $a_type_start + 1)
+                            !== substr($b_code, $b_type_start, $b_type_end - $b_type_start + 1)
+                        ) {
+                            return false;
+                        }
+                    }
+
                     $body_change = substr($a_code, $a_comments_end, $a_end - $a_comments_end)
                         !== substr($b_code, $b_comments_end, $b_end - $b_comments_end);
                 } else {
diff --git a/tests/FileDiffTest.php b/tests/FileDiffTest.php
index 5071174c00f..acc84f404bb 100644
--- a/tests/FileDiffTest.php
+++ b/tests/FileDiffTest.php
@@ -544,6 +544,63 @@ class A {
                 [],
                 [[84, 133]],
             ],
+            'propertyTypeAddition' => [
+                '<?php
+                namespace Foo;
+
+                class A {
+                    public $a;
+                }',
+                '<?php
+                namespace Foo;
+
+                class A {
+                    public string $a;
+                }',
+                [],
+                [],
+                ['foo\a::$a', 'foo\a::$a'],
+                [],
+                [[84, 93]],
+            ],
+            'propertyTypeRemoval' => [
+                '<?php
+                namespace Foo;
+
+                class A {
+                    public string $a;
+                }',
+                '<?php
+                namespace Foo;
+
+                class A {
+                    public $a;
+                }',
+                [],
+                [],
+                ['foo\a::$a', 'foo\a::$a'],
+                [],
+                [[84, 100]],
+            ],
+            'propertyTypeChange' => [
+                '<?php
+                namespace Foo;
+
+                class A {
+                    public string $a;
+                }',
+                '<?php
+                namespace Foo;
+
+                class A {
+                    public ?string $a;
+                }',
+                [],
+                [],
+                ['foo\a::$a', 'foo\a::$a'],
+                [],
+                [[84, 100]],
+            ],
             'addDocblockToFirst' => [
                 '<?php
                 namespace Foo;