adding filters

composer.json

@@ -8,12 +8,10 @@
         "laravel"
     ],
     "license": "MIT",
-    "authors": [
-        {
-            "name": "TNT Studio",
-            "email": "[email protected]"
-        }
-    ],
+    "authors": [{
+        "name": "TNT Studio",
+        "email": "[email protected]"
+    }],
     "require": {
         "php": ">=7.1",
         "teamtnt/tntsearch": "2.*",
@@ -26,8 +24,8 @@
         "illuminate/support": "~5.4|^6.0|^7.0|^8.0"
     },
     "require-dev": {
-        "mockery/mockery": "~0.9|^1.3.1",
-        "phpunit/phpunit": "~5.0|^9.3"
+        "mockery/mockery": "^1.0",
+        "phpunit/phpunit": "^8.0|^9.3"
     },
     "autoload": {
         "psr-4": {
@@ -54,4 +52,4 @@
     },
     "minimum-stability": "dev",
     "prefer-stable": true
-}
+}

phpunit.xml

@@ -1,14 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit backupGlobals="false"
          backupStaticAttributes="false"
+         beStrictAboutTestsThatDoNotTestAnything="false"
          bootstrap="vendor/autoload.php"
          colors="true"
          convertErrorsToExceptions="true"
          convertNoticesToExceptions="true"
          convertWarningsToExceptions="true"
          processIsolation="false"
          stopOnFailure="false"
-         syntaxCheck="false"
 >
     <testsuites>
         <testsuite name="Package Test Suite">

src/Engines/TNTSearchEngine.php

@@ -13,6 +13,8 @@
 
 class TNTSearchEngine extends Engine
 {
+
+    private $filters;
     /**
      * @var TNTSearch
      */
@@ -161,6 +163,9 @@ protected function performSearch(Builder $builder, array $options = [])
                 $options
             );
         }
+
+        $builder->query = $this->applyFilters('query_expansion', $builder->query, get_class($builder->model));
+
         if (isset($this->tnt->config['searchBoolean']) ? $this->tnt->config['searchBoolean'] : false) {
             $res = $this->tnt->searchBoolean($builder->query, $limit);
             event(new SearchPerformed($builder, $res, true));
@@ -408,4 +413,51 @@ public function flush($model)
             unlink($pathToIndex);
         }
     }
+
+    /**
+     * Adds a filter
+     *
+     * @param  string
+     * @param  callback
+     * @return void
+     */
+    public function addFilter($name, $callback)
+    {
+        if (!is_callable($callback, true)) {
+            throw new InvalidArgumentException(sprintf('Filter is an invalid callback: %s.', print_r($callback, true)));
+        }
+        $this->filters[$name][] = $callback;
+    }
+
+    /**
+     * Returns an array of filters
+     *
+     * @param  string
+     * @return array
+     */
+    public function getFilters($name)
+    {
+        return isset($this->filters[$name]) ? $this->filters[$name] : [];
+    }
+
+    /**
+     * Returns a string on which a filter is applied
+     *
+     * @param  string
+     * @param  string
+     * @return string
+     */
+    public function applyFilters($name, $result, $model)
+    {
+        foreach ($this->getFilters($name) as $callback) {
+            // prevent fatal errors, do your own warning or
+            // exception here as you need it.
+            if (!is_callable($callback)) {
+                continue;
+            }
+
+            $result = call_user_func($callback, $result, $model);
+        }
+        return $result;
+    }
 }

tests/TNTSearchEngineTest.php

@@ -1,21 +1,25 @@
 <?php
 
 use Illuminate\Database\Eloquent\Collection;
+use Mockery as m;
+use PHPUnit\Framework\TestCase;
 use TeamTNT\Scout\Engines\TNTSearchEngine;
+use TeamTNT\TNTSearch\TNTSearch;
 
-class TNTSearchEngineTest extends PHPUnit_Framework_TestCase
+class TNTSearchEngineTest extends TestCase
 {
-    public function tearDown()
+
+    protected function tearDown(): void
     {
-        Mockery::close();
+        m::close();
     }
 
     public function test_update_adds_objects_to_index()
     {
-        $client = Mockery::mock('TeamTNT\TNTSearch\TNTSearch');
+        $client = m::mock('TeamTNT\TNTSearch\TNTSearch');
         $client->shouldReceive('createIndex')
             ->with('table.index')
-            ->andReturn($index = Mockery::mock('TeamTNT\TNTSearch\Indexer\TNTIndexer'));
+            ->andReturn($index = m::mock('TeamTNT\TNTSearch\Indexer\TNTIndexer'));
         $index->shouldReceive('setDatabaseHandle');
         $index->shouldReceive('setPrimaryKey');
         $index->shouldReceive('query');
@@ -32,6 +36,28 @@ public function test_update_adds_objects_to_index()
         $engine = new TNTSearchEngine($client);
         $engine->update(Collection::make([new TNTSearchEngineTestModel()]));
     }
+
+    public function testApplyingFilters()
+    {
+        $tnt    = new TNTSearch;
+        $engine = new TeamTNT\Scout\Engines\TNTSearchEngine($tnt);
+
+        $engine->addFilter("query_expansion", function ($query, $model) {
+            if ($query == "test" && $model == "TeamTNT\TNTSearch\TNTSearch") {
+                return "modified-".$query;
+            }
+            return $query;
+
+        });
+
+        $query  = $engine->applyFilters('query_expansion', "test", TNTSearch::class);
+        $query2 = $engine->applyFilters('query_expansion', "test", Collection::class);
+        $query3 = $engine->applyFilters('query_expansion', "test2", TNTSearch::class);
+
+        $this->assertTrue($query == "modified-test");
+        $this->assertTrue($query2 == "test");
+        $this->assertTrue($query3 == "test2");
+    }
 }
 
 class TNTSearchEngineTestModel