From bcaf7aaf80d4878108be38b21341693341e4c5f5 Mon Sep 17 00:00:00 2001
From: Oliver Hader <oliver@typo3.org>
Date: Mon, 1 Feb 2021 17:00:07 +0100
Subject: [PATCH] [FEATURE] Allow to intercept adding issue in IssueBuffer

This change introduces new `BeforeAddIssueEvent` which is invoked
from `IssueBuffer::add`, which allows to collect and intercept code
issue in a generic way.

Resolves: #7528
---
 src/Psalm/Internal/EventDispatcher.php        | 22 ++++++++++++
 src/Psalm/IssueBuffer.php                     |  6 ++++
 .../EventHandler/BeforeAddIssueInterface.php  | 21 +++++++++++
 .../Event/BeforeAddIssueEvent.php             | 36 +++++++++++++++++++
 4 files changed, 85 insertions(+)
 create mode 100644 src/Psalm/Plugin/EventHandler/BeforeAddIssueInterface.php
 create mode 100644 src/Psalm/Plugin/EventHandler/Event/BeforeAddIssueEvent.php

diff --git a/src/Psalm/Internal/EventDispatcher.php b/src/Psalm/Internal/EventDispatcher.php
index 29e8067490d..64f8859488f 100644
--- a/src/Psalm/Internal/EventDispatcher.php
+++ b/src/Psalm/Internal/EventDispatcher.php
@@ -15,6 +15,7 @@
 use Psalm\Plugin\EventHandler\AfterFunctionLikeAnalysisInterface;
 use Psalm\Plugin\EventHandler\AfterMethodCallAnalysisInterface;
 use Psalm\Plugin\EventHandler\AfterStatementAnalysisInterface;
+use Psalm\Plugin\EventHandler\BeforeAddIssueInterface;
 use Psalm\Plugin\EventHandler\BeforeFileAnalysisInterface;
 use Psalm\Plugin\EventHandler\Event\AddRemoveTaintsEvent;
 use Psalm\Plugin\EventHandler\Event\AfterAnalysisEvent;
@@ -29,6 +30,7 @@
 use Psalm\Plugin\EventHandler\Event\AfterFunctionLikeAnalysisEvent;
 use Psalm\Plugin\EventHandler\Event\AfterMethodCallAnalysisEvent;
 use Psalm\Plugin\EventHandler\Event\AfterStatementAnalysisEvent;
+use Psalm\Plugin\EventHandler\Event\BeforeAddIssueEvent;
 use Psalm\Plugin\EventHandler\Event\BeforeFileAnalysisEvent;
 use Psalm\Plugin\EventHandler\Event\StringInterpreterEvent;
 use Psalm\Plugin\EventHandler\RemoveTaintsInterface;
@@ -122,6 +124,11 @@ class EventDispatcher
      */
     public $after_codebase_populated = [];
 
+    /**
+     * @var list<class-string<BeforeAddIssueInterface>>
+     */
+    private array $before_add_issue = [];
+
     /**
      * Static methods to be called after codebase has been populated
      *
@@ -209,6 +216,10 @@ public function registerClass(string $class): void
             $this->after_codebase_populated[] = $class;
         }
 
+        if (is_subclass_of($class, EventHandler\BeforeAddIssueInterface::class)) {
+            $this->before_add_issue[] = $class;
+        }
+
         if (is_subclass_of($class, AfterAnalysisInterface::class)) {
             $this->after_analysis[] = $class;
         }
@@ -330,6 +341,17 @@ public function dispatchAfterCodebasePopulated(AfterCodebasePopulatedEvent $even
         }
     }
 
+    public function dispatchBeforeAddIssue(BeforeAddIssueEvent $event): ?bool
+    {
+        foreach ($this->before_add_issue as $handler) {
+            $result = $handler::beforeAddIssue($event);
+            if (is_bool($result)) {
+                return $result;
+            }
+        }
+        return null;
+    }
+
     public function dispatchAfterAnalysis(AfterAnalysisEvent $event): void
     {
         foreach ($this->after_analysis as $handler) {
diff --git a/src/Psalm/IssueBuffer.php b/src/Psalm/IssueBuffer.php
index 8377ff11db2..a9fe2423c1a 100644
--- a/src/Psalm/IssueBuffer.php
+++ b/src/Psalm/IssueBuffer.php
@@ -16,6 +16,7 @@
 use Psalm\Issue\TaintedInput;
 use Psalm\Issue\UnusedPsalmSuppress;
 use Psalm\Plugin\EventHandler\Event\AfterAnalysisEvent;
+use Psalm\Plugin\EventHandler\Event\BeforeAddIssueEvent;
 use Psalm\Report\CheckstyleReport;
 use Psalm\Report\CodeClimateReport;
 use Psalm\Report\CompactReport;
@@ -250,6 +251,11 @@ public static function add(CodeIssue $e, bool $is_fixable = false): bool
     {
         $config = Config::getInstance();
 
+        $event = new BeforeAddIssueEvent($e, $is_fixable);
+        if ($config->eventDispatcher->dispatchBeforeAddIssue($event) === false) {
+            return false;
+        };
+
         $fqcn_parts = explode('\\', get_class($e));
         $issue_type = array_pop($fqcn_parts);
 
diff --git a/src/Psalm/Plugin/EventHandler/BeforeAddIssueInterface.php b/src/Psalm/Plugin/EventHandler/BeforeAddIssueInterface.php
new file mode 100644
index 00000000000..c52262bc5ae
--- /dev/null
+++ b/src/Psalm/Plugin/EventHandler/BeforeAddIssueInterface.php
@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Psalm\Plugin\EventHandler;
+
+use Psalm\Plugin\EventHandler\Event\BeforeAddIssueEvent;
+
+interface BeforeAddIssueInterface
+{
+    /**
+     * Called before adding a code issue
+     *
+     * @param BeforeAddIssueEvent $event
+     * @return null|bool $event How and whether to continue
+     *  + `null` continue with next event handler
+     *  + `true` stop event handling, keep issue
+     *  + `false` stop event handling, drop/suppress issue
+     */
+    public static function beforeAddIssue(BeforeAddIssueEvent $event): ?bool;
+}
diff --git a/src/Psalm/Plugin/EventHandler/Event/BeforeAddIssueEvent.php b/src/Psalm/Plugin/EventHandler/Event/BeforeAddIssueEvent.php
new file mode 100644
index 00000000000..1452d35d9a7
--- /dev/null
+++ b/src/Psalm/Plugin/EventHandler/Event/BeforeAddIssueEvent.php
@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Psalm\Plugin\EventHandler\Event;
+
+use Psalm\Issue\CodeIssue;
+
+class BeforeAddIssueEvent
+{
+    /**
+     * @var CodeIssue
+     */
+    private CodeIssue $issue;
+
+    /**
+     * @var bool
+     */
+    private bool $fixable;
+
+    public function __construct(CodeIssue $issue, bool $fixable)
+    {
+        $this->issue = $issue;
+        $this->fixable = $fixable;
+    }
+
+    public function getIssue(): CodeIssue
+    {
+        return $this->issue;
+    }
+
+    public function isFixable(): bool
+    {
+        return $this->fixable;
+    }
+}