[rule] Add MaximumIgnoredErrorCountRule enbaled in configuration (#162)

Author: TomasVotruba

README.md

@@ -38,6 +38,17 @@ includes:
 
 But at start, make baby steps with one rule at a time:
 
+Jump to: [Symfony-specific rules](#3-symfony-specific-rules), [Doctrine-specific rules](#2-doctrine-specific-rules) or [PHPUnit-specific rules](#4-phpunit-specific-rules).
+
+## Special rules
+
+Tired of ever growing ignored error count in your `phpstan.neon`? Set hard limit to keep them low:
+
+```yaml
+parameters:
+    maximumIgnoredErrorCount: 50
+```
+
 <br>
 
 ### CheckRequiredInterfaceInContractNamespaceRule

composer.json

@@ -16,7 +16,7 @@
         "symfony/framework-bundle": "6.1.*",
         "symplify/easy-coding-standard": "^12.5",
         "tomasvotruba/class-leak": "^2.0",
-        "rector/rector": "^2.0",
+        "rector/rector": "^2.0.6",
         "phpstan/extension-installer": "^1.4",
         "symplify/phpstan-extensions": "^12.0",
         "tomasvotruba/unused-public": "^2.0",

config/services/services.neon

@@ -1,3 +1,11 @@
+parameters:
+    # related to MaximumIgnoredErrorCountRule
+    maximumIgnoredErrorCount: 0
+
+parametersSchema:
+    # related to MaximumIgnoredErrorCountRule
+    maximumIgnoredErrorCount: int()
+
 services:
     - Symplify\PHPStanRules\NodeTraverser\SimpleCallableNodeTraverser
     - Symplify\PHPStanRules\PhpDocParser\PhpDocNodeTraverser
@@ -16,3 +24,10 @@ services:
 
     # doctrine
     - Symplify\PHPStanRules\Doctrine\DoctrineEntityDocumentAnalyser
+
+    # rules enabled by configuration
+    -
+        class: Symplify\PHPStanRules\Rules\MaximumIgnoredErrorCountRule
+        tags: [phpstan.rules.rule]
+        arguments:
+            limit: %maximumIgnoredErrorCount%

phpstan.neon

@@ -8,6 +8,9 @@ parameters:
 
     level: 8
 
+    # custom configuration
+    maximumIgnoredErrorCount: 10
+
     paths:
         - src
         - config
@@ -45,3 +48,5 @@ parameters:
         - '#Public constant "Symplify\\PHPStanRules\\(.*?)Rule\:\:ERROR_MESSAGE" is never used#'
 
         - '#Although PHPStan\\Node\\InClassNode is covered by backward compatibility promise, this instanceof assumption might break because (.*?) not guaranteed to always stay the same#'
+
+        - '#PHPStan\\DependencyInjection\\NeonAdapter#'

src/Enum/RuleIdentifier.php

@@ -103,4 +103,6 @@ final class RuleIdentifier
     public const NO_GET_IN_CONTROLLER = 'symfony.noGetInController';
 
     public const NO_GET_DOCTRINE_IN_CONTROLLER = 'symfony.noGetDoctrineInController';
+
+    public const MAXIMUM_IGNORED_ERROR_COUNT = 'symplify.maximumIgnoredErrorCount';
 }

src/Rules/MaximumIgnoredErrorCountRule.php

@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Symplify\PHPStanRules\Rules;
+
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\DependencyInjection\NeonAdapter;
+use PHPStan\Node\CollectedDataNode;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+use Symplify\PHPStanRules\Enum\RuleIdentifier;
+
+/**
+ * @implements Rule<CollectedDataNode>
+ */
+final readonly class MaximumIgnoredErrorCountRule implements Rule
+{
+    /**
+     * @var string
+     */
+    public const ERROR_MESSAGE = "Ignored error count %d in phpstan.neon surpassed maximum limit %d.\nInstead of ignoring more errors, fix them to keep your codebase fit.";
+
+    private NeonAdapter $neonAdapter;
+
+    public function __construct(
+        private int $limit = 0
+    ) {
+        $this->neonAdapter = new NeonAdapter();
+    }
+
+    /**
+     * @return class-string<Node>
+     */
+    public function getNodeType(): string
+    {
+        // hack to run this rule just once
+        return CollectedDataNode::class;
+    }
+
+    /**
+     * @param CollectedDataNode $node
+     */
+    public function processNode(Node $node, Scope $scope): array
+    {
+        // not enabled yet, use "
+        if ($this->limit === 0) {
+            return [];
+        }
+
+        $configFilePath = getcwd() . '/phpstan.neon';
+
+        // unable to find config
+        if (! file_exists($configFilePath)) {
+            return [];
+        }
+
+        $phpstanNeon = $this->neonAdapter->load($configFilePath);
+        $ignoreErrors = $phpstanNeon['parameters']['ignoreErrors'] ?? [];
+        if (count($ignoreErrors) <= $this->limit) {
+            return [];
+        }
+
+        $identifierRuleError = RuleErrorBuilder::message(sprintf(self::ERROR_MESSAGE, count($ignoreErrors), $this->limit))
+            ->identifier(RuleIdentifier::MAXIMUM_IGNORED_ERROR_COUNT)
+            ->build();
+
+        return [$identifierRuleError];
+    }
+}