Adjust filter plugin requirements to comply with 4.5.

Per https://moodledev.io/docs/4.5/devupdate#filter-plugins

Fixes #321

Author: kabalin

src/PluginValidate/Requirements/AbstractRequirements.php

@@ -64,6 +64,18 @@ protected function behatTagsFactory(array $tags): array
         return $fileTokens;
     }
 
+    /**
+     * Helper method to check file existence.
+     *
+     * @param string $file
+     *
+     * @return bool
+     */
+    protected function fileExists(string $file): bool
+    {
+        return file_exists($this->plugin->directory . '/' . $file);
+    }
+
     /**
      * An array of required files, paths are relative to the plugin directory.
      *

src/PluginValidate/Requirements/FilterRequirements.php

@@ -21,15 +21,28 @@ class FilterRequirements extends GenericRequirements
 {
     public function getRequiredFiles(): array
     {
-        return array_merge(parent::getRequiredFiles(), [
-            'filter.php',
-        ]);
+        $files = [];
+        if ($this->moodleVersion >= 405) {
+            $files[] = 'classes/text_filter.php';
+        } else {
+            // This must exist in 4.5 if plugin supports older version, but we don't identify support range to validate it.
+            $files[] = 'filter.php';
+        }
+
+        return array_merge(parent::getRequiredFiles(), $files);
     }
 
     public function getRequiredClasses(): array
     {
+        if ($this->moodleVersion <= 404 && !$this->fileExists('classes/text_filter.php')) {
+            // Plugin does not support 4.5, check class presence in filter.php
+            return [
+                FileTokens::create('filter.php')->mustHave('filter_' . $this->plugin->name),
+            ];
+        }
+
         return [
-            FileTokens::create('filter.php')->mustHave('filter_' . $this->plugin->name),
+            FileTokens::create('classes/text_filter.php')->mustHave("filter_{$this->plugin->name}\\text_filter"),
         ];
     }
 

tests/PluginValidate/Requirements/FilterRequirementsTest.php

@@ -23,14 +23,21 @@ class FilterRequirementsTest extends \PHPUnit\Framework\TestCase
      */
     private $requirements;
 
+    /**
+     * @var FilterRequirements
+     */
+    private $requirements404;
+
     protected function setUp(): void
     {
-        $this->requirements = new FilterRequirements(new Plugin('filter_activitynames', 'filter', 'activitynames', ''), 29);
+        $this->requirements404 = new FilterRequirements(new Plugin('filter_activitynames', 'filter', 'activitynames', ''), 404);
+        $this->requirements    = new FilterRequirements(new Plugin('filter_activitynames', 'filter', 'activitynames', ''), 405);
     }
 
     protected function tearDown(): void
     {
-        $this->requirements = null;
+        $this->requirements404 = null;
+        $this->requirements    = null;
     }
 
     public function testResolveRequirements()
@@ -39,29 +46,66 @@ public function testResolveRequirements()
 
         $this->assertInstanceOf(
             'MoodlePluginCI\PluginValidate\Requirements\FilterRequirements',
-            $resolver->resolveRequirements(new Plugin('', 'filter', '', ''), 29)
+            $resolver->resolveRequirements(new Plugin('', 'filter', '', ''), 404)
         );
     }
 
+    public function testGetRequiredFiles404()
+    {
+        $files = $this->requirements404->getRequiredFiles();
+
+        $this->assertTrue(in_array('filter.php', $files, true));
+        $this->assertFalse(in_array('classes/text_filter.php', $files, true));
+        foreach ($files as $file) {
+            $this->assertIsString($file);
+        }
+    }
+
     public function testGetRequiredFiles()
     {
         $files = $this->requirements->getRequiredFiles();
 
-        $this->assertNotEmpty($files);
-        $this->assertTrue(in_array('filter.php', $files, true));
+        $this->assertFalse(in_array('filter.php', $files, true));
+        $this->assertTrue(in_array('classes/text_filter.php', $files, true));
         foreach ($files as $file) {
             $this->assertIsString($file);
         }
     }
 
+    public function testGetRequiredClasses404()
+    {
+        $requirements = $this->getMockBuilder('MoodlePluginCI\PluginValidate\Requirements\FilterRequirements')
+            ->setConstructorArgs([new Plugin('filter_activitynames', 'filter', 'activitynames', ''), 404])
+            ->onlyMethods(['fileExists'])
+            ->getMock();
+        // On first call fileExists return false, on second call return true.
+        $requirements->method('fileExists')
+            ->with($this->identicalTo('classes/text_filter.php'))
+            ->willReturn(false, true);
+
+        // If classes/text_filter.php does not exist, expect class presence in filter.php.
+        $classes = $requirements->getRequiredClasses();
+        $this->assertCount(1, $classes);
+        $class = reset($classes);
+        $this->assertInstanceOf('MoodlePluginCI\PluginValidate\Finder\FileTokens', $class);
+        $this->assertSame('filter.php', $class->file);
+
+        // If classes/text_filter.php exists, expect class presence in it (4.5 plugin backward compatibility).
+        $classes = $requirements->getRequiredClasses();
+        $this->assertCount(1, $classes);
+        $class = reset($classes);
+        $this->assertInstanceOf('MoodlePluginCI\PluginValidate\Finder\FileTokens', $class);
+        $this->assertSame('classes/text_filter.php', $class->file);
+    }
+
     public function testGetRequiredClasses()
     {
         $classes = $this->requirements->getRequiredClasses();
 
-        $this->assertNotEmpty($classes);
-        foreach ($classes as $class) {
-            $this->assertInstanceOf('MoodlePluginCI\PluginValidate\Finder\FileTokens', $class);
-        }
+        $this->assertCount(1, $classes);
+        $class = reset($classes);
+        $this->assertInstanceOf('MoodlePluginCI\PluginValidate\Finder\FileTokens', $class);
+        $this->assertSame('classes/text_filter.php', $class->file);
     }
 
     public function testGetRequiredStrings()