feat: add rule to make sure that raw filter is justified by a comment

src/RawFilterRule.php

@@ -0,0 +1,79 @@
+<?php
+
+namespace Factorial\twigcs;
+
+use FriendsOfTwig\Twigcs\Lexer;
+use FriendsOfTwig\Twigcs\Rule\AbstractRule;
+use FriendsOfTwig\Twigcs\Rule\RuleInterface;
+use FriendsOfTwig\Twigcs\TwigPort\Token;
+use FriendsOfTwig\Twigcs\TwigPort\TokenStream;
+
+/**
+ * Custom Twigcs rule to make sure that "raw" filter is justified by a comment.
+ */
+class RawFilterRule extends AbstractRule implements RuleInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function check(TokenStream $tokens): array {
+
+    $violations = [];
+
+    while (!$tokens->isEOF()) {
+      if ($tokens->isEOF()) {
+        break;
+      }
+      $token = $tokens->getCurrent();
+      if ($new_violations = $this->validateRawFilterComment($token, $tokens)) {
+        $violations = array_merge($violations, $new_violations);
+      }
+      $tokens->next();
+    }
+
+    return $violations;
+  }
+
+  /**
+   * Validates that any raw filter is preceded by a comment.
+   */
+  protected function validateRawFilterComment(Token $token, TokenStream &$tokens): array {
+
+    $violations = [];
+
+    // Consider "|raw" filter.
+    if ($token->getValue() === 'raw' &&
+      Token::NAME_TYPE === $token->getType() &&
+      Token::PUNCTUATION_TYPE === $tokens->look(Lexer::PREVIOUS_TOKEN)->getType()
+    ) {
+
+      $line = $token->getLine();
+      $column = $token->getColumn() + 1;
+      $reason = 'usage of the "raw" filter should be justified in a preceding comment.';
+
+      // If the "raw" filter appears on the first line there can not be a
+      // preceding comment.
+      if ($line === 1) {
+        $violations[] = $this->createViolation($tokens->getSourceContext()->getPath(), $line, $column, $reason);
+        return $violations;
+      }
+
+      // Look behind until the previous line is reached.
+      $look_behind = Lexer::PREVIOUS_TOKEN;
+      while ($previous_token = $tokens->look($look_behind)) {
+        if ($previous_token->getLine() !== $line) {
+          break;
+        }
+        $look_behind--;
+      }
+
+      // Check whether the previous line is a comment.
+      if ($previous_token->getType() !== Token::COMMENT_TYPE) {
+        $violations[] = $this->createViolation($tokens->getSourceContext()->getPath(), $line, $column, $reason);
+      }
+    }
+
+    return $violations;
+  }
+
+}

src/TwigCsRuleset.php

@@ -13,10 +13,11 @@ class TwigCsRuleset extends Official {
   /**
    * @{inheritdoc}
    */
-  public function getRules() {
+  public function getRules(): array {
     $rules = parent::getRules();
     return array_merge($rules, [
       new WithOnlyRule(Violation::SEVERITY_ERROR),
+      new RawFilterRule(Violation::SEVERITY_WARNING),
     ]);
   }
 

tests/RulesetFunctionalTest.php

@@ -0,0 +1,63 @@
+<?php
+
+namespace FriendsOfTwig\Twigcs\Tests;
+
+use Factorial\twigcs\TwigCsRuleset;
+use FriendsOfTwig\Twigcs\Lexer;
+use FriendsOfTwig\Twigcs\Rule\RegEngineRule;
+use FriendsOfTwig\Twigcs\TwigPort\Source;
+use FriendsOfTwig\Twigcs\Validator\Validator;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Provides tests for the custom Twigcs ruleset.
+ *
+ * @author D34dMan <shibinkidd@gmail.com>
+ */
+class RulesetFunctionalTest extends TestCase {
+
+  /**
+   * @dataProvider getData
+   */
+  public function testExpressions($expression, $violationCount): void {
+    $lexer = new Lexer();
+    $validator = new Validator();
+
+    $violations = $validator->validate(new TwigCsRuleset(2), $lexer->tokenize(new Source($expression, 'src', 'src.html.twig')));
+    $this->assertCount(0, $validator->getCollectedData()[RegEngineRule::class]['unrecognized_expressions'] ?? []);
+
+    if ($violationCount) {
+      $this->assertCount($violationCount, $violations, sprintf("There should be %d violation in:\n %s", $violationCount, $expression));
+    }
+    else {
+      $this->assertCount(0, $violations, sprintf("There should be no violations in:\n %s", $expression));
+    }
+  }
+
+  /**
+   * Provides test scenarios.
+   */
+  public function getData(): array {
+    return [
+      // NOTE: We expect exactly 17 violations in the fail scenario.
+      // In case we add more, don't forget to update violation count.
+      [$this->getFailScenarios(), 17],
+      [$this->getPassScenarios(), 0],
+    ];
+  }
+
+  /**
+   * Gets failure scenarios.
+   */
+  public function getFailScenarios() {
+    return file_get_contents(__DIR__ . '/assets/fail.twig');
+  }
+
+  /**
+   * Gets pass scenarios.
+   */
+  public function getPassScenarios() {
+    return file_get_contents(__DIR__ . '/assets/pass.twig');
+  }
+
+}

tests/assets/fail.twig

@@ -26,4 +26,7 @@
   FAIL: {% include "@elements/icon/icon.twig" with {
     only
   } %}
+  FAIL: {{ content|raw }}
+  FAIL: {# Lorem ipsum dolor sit amet. #} {{ content|raw }}
+
 </header>

tests/assets/pass.twig

@@ -28,4 +28,13 @@
   PASS: {% include "@elements/icon/icon.twig" with {
     only
   } only %}
+  PASS:
+  {# Lorem ipsum dolor sit amet. #}
+  {{ content|raw }}
+  PASS:
+  {#
+  Lorem ipsum
+  dolor sit amet.
+  #}
+  {{ content|raw }}
 </header>