From 0198042f981c4771796d591930d4fe466f25bfc7 Mon Sep 17 00:00:00 2001
From: Ruben Gomez <ruben@khromalabs.org>
Date: Wed, 13 May 2020 13:53:40 +0200
Subject: [PATCH 1/2] Added property validUndefinedVariableRegexp to
 VariableAnalysisSniff

---
 .../Sniffs/CodeAnalysis/VariableAnalysisSniff.php    | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/VariableAnalysis/Sniffs/CodeAnalysis/VariableAnalysisSniff.php b/VariableAnalysis/Sniffs/CodeAnalysis/VariableAnalysisSniff.php
index 265a72a4..4759e24d 100644
--- a/VariableAnalysis/Sniffs/CodeAnalysis/VariableAnalysisSniff.php
+++ b/VariableAnalysis/Sniffs/CodeAnalysis/VariableAnalysisSniff.php
@@ -90,6 +90,15 @@ class VariableAnalysisSniff implements Sniff {
    */
   public $validUndefinedVariableNames = null;
 
+  /**
+   *  A PHP regexp string for variables that you want to ignore from undefined
+   *  variable warnings. For example, to ignore the variables `$_junk` and
+   *  `$_unused`, this could be set to `'/^_/'`.
+   *
+   *  @var string|null
+   */
+  public $validUndefinedVariableRegexp= null;
+
   /**
    * Allows unused arguments in a function definition if they are
    * followed by an argument which is used.
@@ -264,6 +273,9 @@ protected function getOrCreateVariableInfo($varName, $currScope) {
       if (in_array($varName, $validUndefinedVariableNames)) {
         $scopeInfo->variables[$varName]->ignoreUndefined = true;
       }
+      if (isset($this->validUndefinedVariableRegexp) && preg_match($this->validUndefinedVariableRegexp, $varName) === 1) {
+        $scopeInfo->variables[$varName]->ignoreUndefined = true;
+      }
     }
     return $scopeInfo->variables[$varName];
   }

From b6cb8767d4b257505280fdefb9e6eb8bb3d60d09 Mon Sep 17 00:00:00 2001
From: Ruben Gomez <ruben@khromalabs.org>
Date: Sat, 6 Jun 2020 22:42:34 +0200
Subject: [PATCH 2/2] Tests: Add test for validUndefinedVariableRegexp

---
 .../VariableAnalysisTest.php                  | 19 +++++++++++++++++++
 .../CodeAnalysis/VariableAnalysisSniff.php    |  2 +-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/Tests/VariableAnalysisSniff/VariableAnalysisTest.php b/Tests/VariableAnalysisSniff/VariableAnalysisTest.php
index e9cf2b11..c259a528 100644
--- a/Tests/VariableAnalysisSniff/VariableAnalysisTest.php
+++ b/Tests/VariableAnalysisSniff/VariableAnalysisTest.php
@@ -793,6 +793,25 @@ public function testValidUndefinedVariableNamesIgnoresUndefinedProperties() {
     $this->assertEquals($expectedWarnings, $lines);
   }
 
+  public function testValidUndefinedVariableRegexpIgnoresUndefinedProperties() {
+    $fixtureFile = $this->getFixture('ClassReferenceFixture.php');
+    $phpcsFile = $this->prepareLocalFileForSniffs($fixtureFile);
+    $phpcsFile->ruleset->setSniffProperty(
+      'VariableAnalysis\Sniffs\CodeAnalysis\VariableAnalysisSniff',
+      'validUndefinedVariableRegexp',
+      '/^undefined_/'
+    );
+    $phpcsFile->process();
+    $lines = $this->getWarningLineNumbersFromFile($phpcsFile);
+    $expectedWarnings = [
+      12,
+      13,
+      24,
+      25
+    ];
+    $this->assertEquals($expectedWarnings, $lines);
+  }
+
   public function testUnusedArgumentsBeforeUsedArgumentsAreFoundIfFalse() {
     $fixtureFile = $this->getFixture('UnusedAfterUsedFixture.php');
     $phpcsFile = $this->prepareLocalFileForSniffs($fixtureFile);
diff --git a/VariableAnalysis/Sniffs/CodeAnalysis/VariableAnalysisSniff.php b/VariableAnalysis/Sniffs/CodeAnalysis/VariableAnalysisSniff.php
index 4759e24d..90ad91db 100644
--- a/VariableAnalysis/Sniffs/CodeAnalysis/VariableAnalysisSniff.php
+++ b/VariableAnalysis/Sniffs/CodeAnalysis/VariableAnalysisSniff.php
@@ -97,7 +97,7 @@ class VariableAnalysisSniff implements Sniff {
    *
    *  @var string|null
    */
-  public $validUndefinedVariableRegexp= null;
+  public $validUndefinedVariableRegexp = null;
 
   /**
    * Allows unused arguments in a function definition if they are