MC-19921: Create static tests for object variables inside E-mail templates

Author: nathanjosiah

dev/tests/static/framework/Magento/Sniffs/Html/HtmlDirectiveSniff.php

@@ -190,6 +190,9 @@ private function validateDefinedVariables(File $phpcsFile, string $templateText)
 
         $extraDefinedVariables = array_diff($definedVariables, $this->usedVariables);
         foreach ($extraDefinedVariables as $extraDefinedVariable) {
+            if (substr($extraDefinedVariable, 0, 4) !== 'var ') {
+                continue;
+            }
             $phpcsFile->addError(
                 'Template @vars comment block contains a variable not used in the template.' . PHP_EOL
                  . 'Extra variable: ' . $extraDefinedVariable,

dev/tests/static/framework/tests/unit/testsuite/Magento/Sniffs/Html/_files/test-html-directive.html

@@ -40,6 +40,7 @@
 "var foo.goodFor|stillfine":"Some Variable",
 "var foo.badFor()":"Some Variable",
 "var foo.badFor()|alsobad":"Some Variable",
+"foobar baz":"Some other directive as a variable",
 "var bad.multiline()":""
 } @-->