From baa5fdad954706e001ba9e50cec41f12e4734d52 Mon Sep 17 00:00:00 2001
From: Alexander Skvortsov <sasha.skvortsov109@gmail.com>
Date: Fri, 13 Nov 2020 02:56:13 -0500
Subject: [PATCH] Add extender and tests for filter

---
 src/Extend/Filter.php                      |  65 ++++++++++
 src/Filter/Filterer.php                    |  20 +--
 tests/integration/extenders/FilterTest.php | 138 +++++++++++++++++++++
 3 files changed, 215 insertions(+), 8 deletions(-)
 create mode 100644 src/Extend/Filter.php
 create mode 100644 tests/integration/extenders/FilterTest.php

diff --git a/src/Extend/Filter.php b/src/Extend/Filter.php
new file mode 100644
index 000000000..65c3156ab
--- /dev/null
+++ b/src/Extend/Filter.php
@@ -0,0 +1,65 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Extend;
+
+use Flarum\Extension\Extension;
+use Flarum\Filter\Filterer;
+use Flarum\Filter\FilterInterface;
+use Flarum\Foundation\ContainerUtil;
+use Illuminate\Contracts\Container\Container;
+
+class Filter implements ExtenderInterface
+{
+    private $resource;
+    private $filters = [];
+    private $filterMutators = [];
+
+    /**
+     * @param string $resource: The ::class attribute of the resource this applies to, which is typically an Eloquent model.
+     */
+    public function __construct($resource)
+    {
+        $this->resource = $resource;
+    }
+
+    /**
+     * Add a filter to run when the resource is filtered
+     *
+     * @param string $filterClass: The ::class attribute of the filter you are adding.
+     */
+    public function addFilter(string $filterClass)
+    {
+        $this->filters[] = $filterClass;
+
+        return $this;
+    }
+
+    /**
+     * Add a callback through which to run all filter queries after filters have been applied.
+     */
+    public function addFilterMutator($callback)
+    {
+        $this->filterMutators[] = $callback;
+
+        return $this;
+    }
+
+    public function extend(Container $container, Extension $extension = null)
+    {
+
+        foreach ($this->filters as $filter) {
+            Filterer::addFilter($this->resource, $container->make($filter));
+        }
+
+        foreach ($this->filterMutators as $mutator) {
+            Filterer::addFilterMutator($this->resource, ContainerUtil::wrapCallback($mutator, $container));
+        }
+    }
+}
diff --git a/src/Filter/Filterer.php b/src/Filter/Filterer.php
index cd844fcde..0d77efca3 100644
--- a/src/Filter/Filterer.php
+++ b/src/Filter/Filterer.php
@@ -21,13 +21,17 @@ class Filterer
 
     protected static $filterMutators = [];
 
-    public static function addFilter($resource, $filterKey, $filter)
+    public static function addFilter($resource, FilterInterface $filter)
     {
         if (!array_key_exists($resource, static::$filters)) {
             static::$filters[$resource] = [];
         }
 
-        static::$filters[$resource][$filterKey] = $filter;
+        if (!array_key_exists($filter->getKey(), static::$filters[$resource])) {
+            static::$filters[$resource][$filter->getKey()] = [];
+        }
+
+        static::$filters[$resource][$filter->getKey()][] = $filter;
     }
 
     public static function addFilterMutator($resource, $mutator)
@@ -52,20 +56,20 @@ class Filterer
 
         $query->whereVisibleTo($actor);
 
-        foreach (Arr::get(static::$filters, $resource, []) as $filterKey => $filterCallback) {
-            if (array_key_exists($filterKey, $filters)) {
-                $filterCallback($query, $filters[$filterKey]);
+        $wrappedFilter = new WrappedFilter($query->getQuery(), $actor);
+
+        foreach ($filters as $filterKey => $filterValue) {
+            foreach (Arr::get(static::$filters, "$resource.$filterKey", []) as $filter) {
+                $filter->apply($wrappedFilter, $filterValue);
             }
         }
 
-        $wrappedFilter = new WrappedFilter($query->getQuery(), $actor);
-
         $this->applySort($wrappedFilter, $sort);
         $this->applyOffset($wrappedFilter, $offset);
         $this->applyLimit($wrappedFilter, $limit + 1);
 
         foreach (Arr::get(static::$filterMutators, $resource, []) as $mutator) {
-            $mutator($wrappedFilter, $filters, $sort);
+            $mutator($query, $actor, $filters, $sort);
         }
 
         // Execute the filter query and retrieve the results. We get one more
diff --git a/tests/integration/extenders/FilterTest.php b/tests/integration/extenders/FilterTest.php
new file mode 100644
index 000000000..5ac67ba7d
--- /dev/null
+++ b/tests/integration/extenders/FilterTest.php
@@ -0,0 +1,138 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Tests\integration\extenders;
+
+use Carbon\Carbon;
+use Flarum\Discussion\Discussion;
+use Flarum\Discussion\Search\DiscussionSearcher;
+use Flarum\Extend;
+use Flarum\Filter\FilterInterface;
+use Flarum\Filter\WrappedFilter;
+use Flarum\Search\AbstractSearch;
+use Flarum\Tests\integration\RetrievesAuthorizedUsers;
+use Flarum\Tests\integration\TestCase;
+use Flarum\User\User;
+
+class FilterTest extends TestCase
+{
+    use RetrievesAuthorizedUsers;
+
+    public function prepDb()
+    {
+        $this->prepareDatabase([
+            'discussions' => [
+                ['id' => 1, 'title' => 'DISCUSSION 1', 'created_at' => Carbon::now()->toDateTimeString(), 'user_id' => 2, 'first_post_id' => 1, 'comment_count' => 1],
+                ['id' => 2, 'title' => 'DISCUSSION 2', 'created_at' => Carbon::now()->toDateTimeString(), 'user_id' => 2, 'first_post_id' => 2, 'comment_count' => 1],
+            ],
+            'posts' => [
+                ['id' => 1, 'discussion_id' => 1, 'created_at' => Carbon::now()->toDateTimeString(), 'user_id' => 2, 'type' => 'comment', 'content' => '<t><p>foo bar</p></t>'],
+                ['id' => 2, 'discussion_id' => 2, 'created_at' => Carbon::now()->toDateTimeString(), 'user_id' => 2, 'type' => 'comment', 'content' => '<t><p>foo bar not the same</p></t>'],
+            ],
+            'users' => [
+                $this->adminUser(),
+                $this->normalUser(),
+            ],
+        ]);
+    }
+
+    public function filterDiscussions($filters, $limit = null)
+    {
+        $response = $this->send(
+            $this->request('GET', '/api/discussions', [
+                'authenticatedAs' => 1,
+            ])->withQueryParams([
+                'filter' => $filters,
+                'include' => 'mostRelevantPost',
+            ])
+        );
+
+        return json_decode($response->getBody()->getContents(), true)['data'];
+    }
+
+    /**
+     * @test
+     */
+    public function works_as_expected_with_no_modifications()
+    {
+        $this->prepDb();
+
+        $searchForAll = json_encode($this->filterDiscussions([], 5));
+        $this->assertContains('DISCUSSION 1', $searchForAll);
+        $this->assertContains('DISCUSSION 2', $searchForAll);
+    }
+
+    /**
+     * @test
+     */
+    public function custom_filter_gambit_has_effect_if_added()
+    {
+        $this->extend((new Extend\Filter(Discussion::class))->addFilter(NoResultFilter::class));
+
+        $this->prepDb();
+
+        $withResultSearch = json_encode($this->filterDiscussions(['noResult' => 0], 5));
+        $this->assertContains('DISCUSSION 1', $withResultSearch);
+        $this->assertContains('DISCUSSION 2', $withResultSearch);
+        $this->assertEquals([], $this->filterDiscussions(['noResult' => 1], 5));
+    }
+
+    /**
+     * @test
+     */
+    public function filter_mutator_has_effect_if_added()
+    {
+        $this->extend((new Extend\Filter(Discussion::class))->addFilterMutator(function ($query, $actor, $filters, $sort) {
+            $query->getQuery()->whereRaw('1=0');
+        }));
+
+        $this->prepDb();
+
+        $this->assertEquals([], $this->filterDiscussions([], 5));
+    }
+
+    /**
+     * @test
+     */
+    public function filter_mutator_has_effect_if_added_with_invokable_class()
+    {
+        $this->extend((new Extend\Filter(Discussion::class))->addFilterMutator(CustomFilterMutator::class));
+
+        $this->prepDb();
+
+        $this->assertEquals([], $this->filterDiscussions([], 5));
+    }
+}
+
+class NoResultFilter implements FilterInterface
+{
+    public function getKey(): string
+    {
+        return 'noResult';
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function apply(WrappedFilter $wrappedFilter, $filterValue)
+    {
+        if ($filterValue) {
+            $wrappedFilter->getQuery()
+                ->whereRaw('0=1');
+        }
+    }
+}
+
+class CustomFilterMutator
+{
+    public function __invoke($query, $actor, $filters, $sort)
+    {
+        $query->getQuery()->whereRaw('1=0');
+    }
+}