PrintingFunctionsTrait: make sure function names are checked case-ins…

…ensitively

These functions should be self-contained, so should not presume that the sniff has already lowercased the function name before passing it.

This fixes a bug as, in this case, the sniff didn't actually lowercase the name before passing it to the trait method, so the sniff would throw false negatives for non-lowercase function calls.

Tested by adjusting some pre-existing tests for the `EscapeOutput` sniff.

WordPress/Helpers/PrintingFunctionsTrait.php

@@ -107,6 +107,6 @@ public function is_printing_function( $functionName ) {
 			$this->addedCustomPrintingFunctions = $this->customPrintingFunctions;
 		}
 
-		return isset( $this->allPrintingFunctions[ $functionName ] );
+		return isset( $this->allPrintingFunctions[ strtolower( $functionName ) ] );
 	}
 }

WordPress/Tests/Security/EscapeOutputUnitTest.inc

@@ -128,7 +128,7 @@ echo $html_fragment; // WPCS: XSS whitelist.
 ?><?php echo $html_fragment; // XSS pass. ?><?php
 
 _deprecated_function( __FUNCTION__, '1.3.0', 'another_func' ); // Ok.
-_deprecated_function( __FUNCTION__, '1.3.0', $another_func ); // Bad.
+_Deprecated_Function( __FUNCTION__, '1.3.0', $another_func ); // Bad.
 _deprecated_function( __FUNCTION__, '1.3.0', esc_html( $another_func ) ); // Ok.
 _deprecated_file( __FILE__, '1.3.0' ); // Ok.
 _deprecated_argument( __METHOD__, '1.3.0', 'The $arg is deprecated.' ); // Ok.
@@ -261,7 +261,7 @@ echo esc_html_x( $some_nasty_var, 'context' ); // Ok.
 echo PHP_VERSION_ID, PHP_VERSION, PHP_EOL, PHP_EXTRA_VERSION; // OK.
 
 trigger_error( 'DEBUG INFO - ' . __METHOD__ . '::internal_domains: domain = ' . $domain ); // Bad.
-trigger_error( $domain ); // Bad.
+Trigger_ERROR( $domain ); // Bad.
 
 vprintf( 'Hello %s', [ $foo ] ); // Bad.
 vprintf( 'Hello %s', [ esc_html( $foo ) ] ); // Ok.