bug #4327 TokensAnalyzer - add concat operator to list of binary operators (SpacePossum)

This PR was squashed before being merged into the 2.12 branch (closes #4327).

Discussion
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TokensAnalyzer - add concat operator to list of binary operators

Commits
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20699b5 TokensAnalyzer - add concat operator to list of binary operators

Author: SpacePossum

src/Fixer/ControlStructure/YodaStyleFixer.php

@@ -527,7 +527,7 @@ private function isVariable(Tokens $tokens, $start, $end, $strict)
                 if (
                     $tokens[$index]->isCast()
                     || $tokens[$index]->isGivenKind(T_INSTANCEOF)
-                    || $tokens[$index]->equalsAny(['.', '!'])
+                    || $tokens[$index]->equals('!')
                     || $tokenAnalyzer->isBinaryOperator($index)
                 ) {
                     return false;

src/Tokenizer/TokensAnalyzer.php

@@ -504,6 +504,7 @@ public function isBinaryOperator($index)
             '>' => true,
             '|' => true,
             '^' => true,
+            '.' => true,
         ];
 
         static $potentialUnaryNonArrayOperators = [

tests/Fixer/ControlStructure/YodaStyleFixerTest.php

@@ -445,6 +445,11 @@ function foo() {
                 '<?php return $k === $myVar + 2;',
                 ['always_move_variable' => true],
             ],
+            [
+                '<?php return $myVar . $b === $k;',
+                '<?php return $k === $myVar . $b;',
+                ['always_move_variable' => true],
+            ],
             [
                 '<?php return $myVar - 2 === $k;',
                 '<?php return $k === $myVar - 2;',

tests/Tokenizer/TokensAnalyzerTest.php

@@ -890,6 +890,26 @@ public function testIsBinaryOperator($source, array $expected)
     public function provideIsBinaryOperatorCases()
     {
         $cases = [
+            [
+                '<?php $a .= $b; ?>',
+                [3 => true],
+            ],
+            [
+                '<?php $a . \'a\' ?>',
+                [3 => true],
+            ],
+            [
+                '<?php $a &+ $b;',
+                [3 => true],
+            ],
+            [
+                '<?php $a && $b;',
+                [3 => true],
+            ],
+            [
+                '<?php $a & $b;',
+                [3 => true],
+            ],
             [
                 '<?php [] + [];',
                 [4 => true],