Fix union result with mysqli (#703)

src/MysqliReflection/MysqliResultObjectType.php

@@ -4,6 +4,7 @@
 
 namespace staabm\PHPStanDba\MysqliReflection;
 
+use PHPStan\TrinaryLogic;
 use PHPStan\Type\ObjectType;
 use PHPStan\Type\Type;
 
@@ -24,4 +25,31 @@ public function getIterableValueType(): \PHPStan\Type\Type
 
         return parent::getIterableValueType();
     }
+
+    // differentiate objects based on the local properties,
+    // to make sure TypeCombinator::union() will not normalize separate objects away.
+    // this means we need to implement equals() and isSuperTypeOf().
+    public function equals(Type $type): bool
+    {
+        if ($type instanceof self) {
+            return $type->rowType !== null
+                && $this->rowType !== null
+                && $type->rowType->equals($this->rowType);
+        }
+
+        return parent::equals($type);
+    }
+
+    public function isSuperTypeOf(Type $type): TrinaryLogic
+    {
+        if ($type instanceof self) {
+            return TrinaryLogic::createFromBoolean(
+                $type->rowType !== null
+                && $this->rowType !== null
+                && $type->rowType->equals($this->rowType)
+            );
+        }
+
+        return parent::isSuperTypeOf($type);
+    }
 }

tests/default/data/mysqli.php

@@ -44,4 +44,17 @@ public function fnQuery(mysqli $mysqli, string $query)
         $result = mysqli_query($mysqli, $query);
         assertType('mysqli_result|true', $result);
     }
+
+    public function unionResult(mysqli $mysqli)
+    {
+        $queries = ['SELECT adaid FROM ada', 'SELECT email FROM ada'];
+
+        foreach ($queries as $query) {
+            $result = $mysqli->query($query);
+
+            foreach ($result as $row) {
+                assertType('array{adaid: int<-32768, 32767>}|array{email: string}', $row);
+            }
+        }
+    }
 }