[AutoImport] Handle FQCN in/not in use on auto import + remove unused import as prefix = suffix (#7957)

* Add test case for issue with Carbon import

* fix fixture php line to enable clearer error showing

* Second example with Illuminate\Support\Carbon

* rename test files after discussion

* move to tests

* update fixture namespace

* [AutoImport] Handle FQCN in/not in use on auto import + remove unused import

---------

Co-authored-by: Kathryn Reeve <67553+BinaryKitten@users.noreply.github.com>

Author: samsonasik

rules/TypeDeclaration/PHPStan/ObjectTypeSpecifier.php

@@ -51,14 +51,16 @@ public function narrowToFullyQualifiedOrAliasedObjectType(
 
         $uses = $this->useImportsResolver->resolve();
 
-        $aliasedObjectType = $this->matchAliasedObjectType($objectType, $uses);
-        if ($aliasedObjectType instanceof AliasedObjectType) {
-            return $aliasedObjectType;
-        }
+        if (! $withPreslash) {
+            $aliasedObjectType = $this->matchAliasedObjectType($objectType, $uses);
+            if ($aliasedObjectType instanceof AliasedObjectType) {
+                return $aliasedObjectType;
+            }
 
-        $shortenedObjectType = $this->matchShortenedObjectType($objectType, $uses);
-        if ($shortenedObjectType !== null) {
-            return $shortenedObjectType;
+            $shortenedObjectType = $this->matchShortenedObjectType($objectType, $uses);
+            if ($shortenedObjectType !== null) {
+                return $shortenedObjectType;
+            }
         }
 
         if ($this->reflectionProvider->hasClass($className)) {

stubs/Carbon/CarbonInterface.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace Carbon;
+
+if (interface_exists('Carbon\CarbonInterface')) {
+    return;
+}
+
+interface CarbonInterface
+{
+
+}

tests/Issues/NamespacedUseAutoImport/Fixture/in_use_fqcn_docblock.php.inc

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\Issues\NamespacedUseAutoImport\Fixture;
+
+use Carbon\Carbon;
+use Carbon\CarbonInterface;
+
+/**
+ * @property \Carbon\CarbonInterface|null $deleted_at
+ */
+class InUseFqcnDocblock
+{
+    /**
+     * @return CarbonInterface[]
+     */
+    public function demoFunction(): array
+    {
+        return [Carbon::parse('2026-01-01 11:16:01')];
+    }
+}
+
+?>
+-----
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\Issues\NamespacedUseAutoImport\Fixture;
+
+use Carbon\Carbon;
+use Carbon\CarbonInterface;
+
+/**
+ * @property CarbonInterface|null $deleted_at
+ */
+class InUseFqcnDocblock
+{
+    /**
+     * @return CarbonInterface[]
+     */
+    public function demoFunction(): array
+    {
+        return [Carbon::parse('2026-01-01 11:16:01')];
+    }
+}
+
+?>

tests/Issues/NamespacedUseAutoImport/Fixture/not_in_use_fqcn_docblock.php.inc

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\Issues\NamespacedUseAutoImport\Fixture;
+
+use Illuminate\Support\Carbon;
+use Carbon\CarbonInterface;
+
+/**
+ * @property \Carbon\CarbonInterface|null $deleted_at
+ */
+class NotInUseFqcnDocblock
+{
+    public function demoFunction(): array
+    {
+        return [Carbon::parse('2026-01-01 11:16:01')];
+    }
+}
+
+?>
+-----
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\Issues\NamespacedUseAutoImport\Fixture;
+
+use Illuminate\Support\Carbon;
+use Carbon\CarbonInterface;
+
+/**
+ * @property CarbonInterface|null $deleted_at
+ */
+class NotInUseFqcnDocblock
+{
+    public function demoFunction(): array
+    {
+        return [Carbon::parse('2026-01-01 11:16:01')];
+    }
+}
+
+?>

tests/Issues/NamespacedUseAutoImport/Fixture/not_in_use_fqcn_docblock_2.inc

@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\Issues\NamespacedUseAutoImport\Fixture;
+
+use Carbon\Carbon;
+use Carbon\CarbonInterface;
+
+/**
+ * @property \Carbon\CarbonInterface|null $deleted_at
+ */
+class NotInUseFqcnDocblock2
+{
+    public function demoFunction(): array
+    {
+        return [Carbon::parse('2026-01-01 11:16:01')];
+    }
+}
+
+?>
+-----
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\Issues\NamespacedUseAutoImport\Fixture;
+
+use Carbon\Carbon;
+
+/**
+ * @property CarbonInterface|null $deleted_at
+ */
+class NotInUseFqcnDocblock2
+{
+    public function demoFunction(): array
+    {
+        return [Carbon::parse('2026-01-01 11:16:01')];
+    }
+}
+
+?>