Fix #4827 - don’t eradicate double after int check

src/Psalm/Internal/Type/AssertionReconciler.php

@@ -476,7 +476,12 @@ class AssertionReconciler extends \Psalm\Type\Reconciler
                 && UnionTypeComparator::isContainedBy(
                     $codebase,
                     $existing_var_type,
-                    $new_type
+                    $new_type,
+                    false,
+                    false,
+                    null,
+                    false,
+                    false
                 )
             ) {
                 self::triggerIssueForImpossible(

src/Psalm/Internal/Type/Comparator/UnionTypeComparator.php

@@ -27,7 +27,8 @@ class UnionTypeComparator
         bool $ignore_null = false,
         bool $ignore_false = false,
         ?TypeComparisonResult $union_comparison_result = null,
-        bool $allow_interface_equality = false
+        bool $allow_interface_equality = false,
+        bool $allow_float_int_equality = true
     ) : bool {
         if ($union_comparison_result) {
             $union_comparison_result->scalar_type_match_found = true;
@@ -108,7 +109,7 @@ class UnionTypeComparator
                     $input_type_part,
                     $container_type_part,
                     $allow_interface_equality,
-                    true,
+                    $allow_float_int_equality,
                     $atomic_comparison_result
                 );
 

tests/FunctionCallTest.php

@@ -1406,6 +1406,22 @@ class FunctionCallTest extends TestCase
                 [],
                 '8.0'
             ],
+            'getTypeDoubleThenInt' => [
+                '<?php
+                    function safe_float(mixed $val): bool {
+                        switch (gettype($val)) {
+                            case "double":
+                            case "integer":
+                                return true;
+                            // ... more cases omitted
+                            default:
+                                return false;
+                        }
+                    }',
+                [],
+                [],
+                '8.0'
+            ],
         ];
     }