Added lower camel case variable name sniff

Author: fa-grosch

custom-standards/Flyeralarm/Sniffs/Variable/LowerCamelCaseSniff.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace flyeralarm\CodingGuidelines\Flyeralarm\Sniffs\Variable;
+
+use PHP_CodeSniffer\Sniffs\Sniff;
+use PHP_CodeSniffer\Files\File;
+use PHP_CodeSniffer\Util\Common;
+
+class LowerCamelCaseSniff implements Sniff
+{
+    /**
+     * @return array
+     */
+    public function register()
+    {
+        return array(T_OPEN_TAG);
+    }
+
+    /**
+     * @param File $phpcsFile
+     * @param int $stackPtr
+     * @return void
+     */
+    public function process(File $phpcsFile, $stackPtr)
+    {
+        $startPtr = $stackPtr;
+        $tokens = $phpcsFile->getTokens();
+
+        while ($variablePtr = $phpcsFile->findNext(T_VARIABLE, $startPtr)) {
+            $startPtr = $variablePtr + 1;
+
+            $variableName = $tokens[$variablePtr]['content'];
+            $variableName = substr($variableName, 1);
+
+            $isLowerCamelCase = Common::isCamelCaps($variableName, false, true, true);
+            if ($isLowerCamelCase) {
+                continue;
+            }
+            if (strtolower($variableName) == $variableName) {
+                continue;
+            }
+
+            $phpcsFile->addError(
+                'Variable names must be specified in lower camel case',
+                $variablePtr,
+                'CamelCase'
+            );
+        }
+    }
+}

ruleset.xml

@@ -12,5 +12,6 @@
     <rule ref="./custom-standards/Flyeralarm/Sniffs/File/NoClassKindSuffixSniff.php"/>
     <rule ref="./custom-standards/Flyeralarm/Sniffs/Docblock/ReturnTypeSniff.php"/>
     <rule ref="./custom-standards/Flyeralarm/Sniffs/Docblock/ExpectedExceptionMessageSniff.php"/>
+    <rule ref="./custom-standards/Flyeralarm/Sniffs/Variable/LowerCamelCaseSniff.php"/>
     <rule ref="./custom-standards/Flyeralarm/Sniffs/ControlStructures/YodaSniff.php"/>
 </ruleset>

tests/rules/variables/not-allowed/UpperCamelCase.php

@@ -0,0 +1,5 @@
+<?php
+
+// @expectedError Variable names must be specified in lower camel case
+
+$UpperCamelCase = true;

tests/rules/variables/not-allowed/VariableWithTwoConsecutiveUpperCaseLetters.php

@@ -0,0 +1,5 @@
+<?php
+
+// @expectedError Variable names must be specified in lower camel case
+
+$fooBAr = true;