feat: unused views collector rule

extension.neon

@@ -262,11 +262,6 @@ services:
         tags:
             - phpstan.broker.dynamicFunctionReturnTypeExtension
 
-    -
-        class: NunoMaduro\Larastan\ReturnTypes\Helpers\ViewExtension
-        tags:
-            - phpstan.broker.dynamicFunctionReturnTypeExtension
-
     -
         class: NunoMaduro\Larastan\ReturnTypes\Helpers\ValidatorExtension
         tags:
@@ -442,6 +437,21 @@ services:
     -
         class: NunoMaduro\Larastan\LarastanStubFilesExtension
         tags: [phpstan.stubFilesExtension]
+
+    -
+        class: NunoMaduro\Larastan\Rules\UnusedViewsRule
+        tags:
+            - phpstan.rules.rule
+
+    -
+        class: NunoMaduro\Larastan\Collectors\UsedViewFunctionCollector
+        tags:
+            - phpstan.collector
+
+    -
+        class: NunoMaduro\Larastan\Collectors\UsedEmailViewCollector
+        tags:
+            - phpstan.collector
 rules:
     - NunoMaduro\Larastan\Rules\RelationExistenceRule
     - NunoMaduro\Larastan\Rules\UselessConstructs\NoUselessWithFunctionCallsRule

src/Collectors/UsedEmailViewCollector.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace NunoMaduro\Larastan\Collectors;
+
+use Illuminate\Mail\Mailable;
+use Illuminate\View\ViewName;
+use PhpParser\Node;
+use PhpParser\Node\Identifier;
+use PHPStan\Analyser\Scope;
+use PHPStan\Collectors\Collector;
+use PHPStan\Type\ObjectType;
+
+/** @implements Collector<Node\Expr\MethodCall, string> */
+final class UsedEmailViewCollector implements Collector
+{
+    public function getNodeType(): string
+    {
+        return Node\Expr\MethodCall::class;
+    }
+
+    /** @param Node\Expr\MethodCall $node */
+    public function processNode(Node $node, Scope $scope): ?string
+    {
+        $name = $node->name;
+
+        if (! $name instanceof Identifier) {
+            return null;
+        }
+
+        if ($name->name !== 'markdown') {
+            return null;
+        }
+
+        if (count($node->getArgs()) === 0) {
+            return null;
+        }
+
+        $class = $node->var;
+
+        if (! (new ObjectType(Mailable::class))->isSuperTypeOf($scope->getType($class))->yes()) {
+            return null;
+        }
+
+        $template = $node->getArgs()[0]->value;
+
+        if (! $template instanceof Node\Scalar\String_) {
+            return null;
+        }
+
+        return ViewName::normalize($template->value);
+    }
+}

src/Collectors/UsedViewFunctionCollector.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace NunoMaduro\Larastan\Collectors;
+
+use Illuminate\View\ViewName;
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\Collectors\Collector;
+
+/** @implements Collector<Node\Expr\FuncCall, string> */
+final class UsedViewFunctionCollector implements Collector
+{
+    public function getNodeType(): string
+    {
+        return Node\Expr\FuncCall::class;
+    }
+
+    /** @param Node\Expr\FuncCall $node */
+    public function processNode(Node $node, Scope $scope): ?string
+    {
+        $funcName = $node->name;
+
+        if (! $funcName instanceof Node\Name) {
+            return null;
+        }
+
+        $funcName = $scope->resolveName($funcName);
+
+        if ($funcName !== 'view') {
+            return null;
+        }
+
+        // TODO: maybe make sure this function is coming from Laravel
+
+        if (count($node->getArgs()) < 1) {
+            return null;
+        }
+
+        $template = $node->getArgs()[0]->value;
+
+        if (! $template instanceof Node\Scalar\String_) {
+            return null;
+        }
+
+        return ViewName::normalize($template->value);
+    }
+}

src/Rules/UnusedViewsRule.php

@@ -0,0 +1,60 @@
+<?php
+
+declare(strict_types=1);
+
+namespace NunoMaduro\Larastan\Rules;
+
+use Illuminate\Support\Facades\File;
+use Illuminate\View\Factory;
+use NunoMaduro\Larastan\Collectors\UsedEmailViewCollector;
+use NunoMaduro\Larastan\Collectors\UsedViewFunctionCollector;
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\Node\CollectedDataNode;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+use Symfony\Component\Finder\SplFileInfo;
+
+/** @implements Rule<CollectedDataNode> */
+final class UnusedViewsRule implements Rule
+{
+    public function getNodeType(): string
+    {
+        return CollectedDataNode::class;
+    }
+
+    public function processNode(Node $node, Scope $scope): array
+    {
+        $usedViews = array_unique(array_merge(...array_values($node->get(UsedViewFunctionCollector::class)), ...array_values($node->get(UsedEmailViewCollector::class))));
+
+        $allViews = array_map(function (SplFileInfo $file) {
+            return $file->getPathname();
+        }, array_filter(File::allFiles(resource_path('views')), function (SplFileInfo $file) {
+            return ! str_contains($file->getPathname(), 'views/vendor') && $file->getExtension() === 'php' && str_ends_with($file->getFilename(), '.blade.php');
+        }));
+
+        $existingViews = [];
+
+        /** @var Factory $view */
+        $view = view();
+
+        foreach ($usedViews as $viewName) {
+            // Not existing views are reported with `view-string` type
+            if ($view->exists($viewName)) {
+                $existingViews[] = $view->getFinder()->find($viewName);
+            }
+        }
+
+        $unusedViews = array_diff($allViews, $existingViews);
+
+        $errors = [];
+        foreach ($unusedViews as $file) {
+            $errors[] = RuleErrorBuilder::message('This view is not used in the project.')
+                ->file($file)
+                ->line(0)
+                ->build();
+        }
+
+        return $errors;
+    }
+}

stubs/Contracts/View.stub

@@ -0,0 +1,9 @@
+<?php
+
+namespace Illuminate\Contracts\View;
+
+interface Factory
+{}
+
+interface View
+{}

stubs/Helpers.stub

@@ -126,7 +126,7 @@ function tap($value, $callback = null)
  * @param  view-string|null  $view
  * @param  \Illuminate\Contracts\Support\Arrayable<array-key, mixed>|array<string, mixed>  $data
  * @param  array<string, mixed>  $mergeData
- * @return mixed
+ * @return ($view is null ? \Illuminate\Contracts\View\Factory : \Illuminate\Contracts\View\View)
  */
 function view($view = null, $data = [], $mergeData = [])
 {

tests/Rules/Data/FooController.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace Tests\Rules\Data;
+
+use Illuminate\Contracts\View\View;
+use Illuminate\Mail\Mailable;
+
+class FooController
+{
+    public function existing(): View
+    {
+        return view('users.index');
+    }
+
+    public function existingNested(): View
+    {
+        return view('emails.orders.shipped');
+    }
+
+    public function notExisting(): View
+    {
+        return view('foo');
+    }
+}
+
+class FooEmail extends Mailable
+{
+    public function build(): self
+    {
+        return $this->markdown('emails.orders.shipped');
+    }
+
+    public function foo(): self
+    {
+        return $this->markdown('home');
+    }
+}

tests/Rules/UnusedViewsRuleTest.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Rules;
+
+use NunoMaduro\Larastan\Collectors\UsedEmailViewCollector;
+use NunoMaduro\Larastan\Collectors\UsedViewFunctionCollector;
+use NunoMaduro\Larastan\Rules\UnusedViewsRule;
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+
+/** @extends RuleTestCase<UnusedViewsRule> */
+class UnusedViewsRuleTest extends RuleTestCase
+{
+    protected function getRule(): Rule
+    {
+        return new UnusedViewsRule;
+    }
+
+    protected function getCollectors(): array
+    {
+        return [
+            new UsedViewFunctionCollector,
+            new UsedEmailViewCollector,
+        ];
+    }
+
+    public function testRule(): void
+    {
+        $this->analyse([__DIR__.'/Data/FooController.php'], [
+            [
+                'This view is not used in the project.',
+                00,
+            ],
+            [
+                'This view is not used in the project.',
+                00,
+            ],
+        ]);
+    }
+}

tests/Type/data/view.php

@@ -4,6 +4,7 @@
 
 use function PHPStan\Testing\assertType;
 
+assertType('Illuminate\Contracts\View\Factory', view());
 assertType('Illuminate\View\View', view('foo'));
 assertType('Illuminate\View\View', view('foo')->with('bar', 'baz'));
 assertType('Illuminate\View\View', view('foo')->withFoo('bar'));