Add sniff to disallow alternative PHP open tags.

Fixes WordPress#580

This should be removed again if the upstream issue squizlabs/PHP_CodeSniffer#1063 would get traction and the associated PR would be merged *and* the minimum PHPCS version for WPCS would become higher than the version in which the PR is merged ;-)

WordPress-Core/ruleset.xml

@@ -21,6 +21,7 @@
 
 	<!-- http://make.wordpress.org/core/handbook/coding-standards/php/#no-shorthand-php-tags -->
 	<rule ref="Generic.PHP.DisallowShortOpenTag"/>
+	<rule ref="WordPress.PHP.DisallowAlternativeOpenTag"/>
 
 	<!-- important to prevent issues with content being sent before headers -->
 	<rule ref="Generic.Files.ByteOrderMark"/>

WordPress/Sniffs/PHP/DisallowAlternativeOpenTagSniff.php

@@ -0,0 +1,123 @@
+<?php
+/**
+ * WordPress Coding Standard.
+ *
+ * @category PHP
+ * @package  PHP_CodeSniffer
+ * @link     https://make.wordpress.org/core/handbook/best-practices/coding-standards/
+ */
+
+/**
+ * Makes sure that no alternative PHP open tags are used.
+ *
+ * @link     https://github.com/WordPress-Coding-Standards/WordPress-Coding-Standards/issues/580
+ *
+ * @category PHP
+ * @package  PHP_CodeSniffer
+ * @author   Juliette Reinders Folmer <wpplugins_nospam@adviesenzo.nl>
+ */
+class WordPress_Sniffs_PHP_DisallowAlternativeOpenTagSniff implements PHP_CodeSniffer_Sniff {
+
+	/**
+	 * Returns an array of tokens this test wants to listen for.
+	 *
+	 * @return array
+	 */
+	public function register() {
+		$tokens = array(
+			T_OPEN_TAG,
+			T_OPEN_TAG_WITH_ECHO,
+		);
+
+		$asp_enabled   = (boolean) ini_get( 'asp_tags' );
+		$short_enabled = (boolean) ini_get( 'short_open_tag' );
+
+		if ( false === $asp_enabled || ( true === $asp_enabled && false === $short_enabled ) ) {
+			$tokens[] = T_INLINE_HTML;
+		}
+
+		return $tokens;
+
+	} // end register()
+
+	/**
+	 * Processes this test, when one of its tokens is encountered.
+	 *
+	 * @param PHP_CodeSniffer_File $phpcsFile The file being scanned.
+	 * @param int                  $stackPtr  The position of the current token
+	 *                                        in the stack passed in $tokens.
+	 *
+	 * @return void
+	 */
+	public function process( PHP_CodeSniffer_File $phpcsFile, $stackPtr ) {
+		$tokens        = $phpcsFile->getTokens();
+		$openTag       = $tokens[ $stackPtr ];
+		$asp_enabled   = (boolean) ini_get( 'asp_tags' );
+		$short_enabled = (boolean) ini_get( 'short_open_tag' );
+
+		if ( T_OPEN_TAG === $openTag['code'] ) {
+			if ( '<%' === $openTag['content'] ) {
+				$error = 'ASP style opening tag used; expected "<?php" but found "%s"';
+				$data  = array( $openTag['content'] );
+				$phpcsFile->addError( $error, $stackPtr, 'ASPOpenTagFound', $data );
+			}
+
+			if ( '<script language="php">' === $openTag['content'] ) {
+				$error = 'Script style opening tag used; expected "<?php" but found "%s"';
+				$data  = array( $openTag['content'] );
+				$phpcsFile->addError( $error, $stackPtr, 'ScriptOpenTagFound', $data );
+			}
+		}
+
+		if ( T_OPEN_TAG_WITH_ECHO === $openTag['code'] && '<%=' === $openTag['content'] ) {
+			$error   = 'ASP style opening tag used with echo; expected "<?php echo %s ..." but found "%s %s ..."';
+			$nextVar = $tokens[ $phpcsFile->findNext( PHP_CodeSniffer_Tokens::$emptyTokens, ( $stackPtr + 1 ), null, true ) ];
+			$data    = array(
+				$nextVar['content'],
+				$openTag['content'],
+				$nextVar['content'],
+			);
+			$phpcsFile->addError( $error, $stackPtr, 'ASPShortOpenTagFound', $data );
+		}
+
+		if ( ( true === $asp_enabled && false === $short_enabled ) && ( T_INLINE_HTML === $openTag['code'] && 0 === strpos( $openTag['content'], '<%=' ) ) ) {
+
+			$error = 'Possible use of ASP style short opening tags. Needs manual inspection. Found: %s';
+			$data  = array( $this->get_snippet( $openTag['content'] ) );
+			$phpcsFile->addWarning( $error, $stackPtr, 'MaybeASPShortOpenTagFound', $data );
+		}
+
+		if ( false === $asp_enabled && T_INLINE_HTML === $openTag['code'] ) {
+
+			$data  = array( $this->get_snippet( $openTag['content'] ) );
+
+			if ( 0 === strpos( $openTag['content'], '<%=' ) ) {
+				$error = 'Possible use of ASP style short opening tags. Needs manual inspection. Found: %s';
+				$phpcsFile->addWarning( $error, $stackPtr, 'MaybeASPShortOpenTagFound', $data );
+			} elseif ( 0 === strpos( $openTag['content'], '<%' ) ) {
+				$error = 'Possible use of ASP style opening tags. Needs manual inspection. Found: %s';
+				$phpcsFile->addWarning( $error, $stackPtr, 'MaybeASPOpenTagFound', $data );
+			} elseif ( 0 === strpos( $openTag['content'], '<script language="php">' ) ) {
+				$error = 'Script style opening tag used; expected "<?php" but found "%s"';
+				$phpcsFile->addError( $error, $stackPtr, 'ScriptOpenTagFound', $data );
+			}
+		}
+
+	} // end process()
+
+	/**
+	 * Get a snippet from a HTML token.
+	 *
+	 * @param string $content The content of the HTML token.
+	 * @param int    $length  The target length of the snippet to get. Defaults to 40.
+	 * @return string
+	 */
+	private function get_snippet( $content, $length = 40 ) {
+		$snippet = substr( $content, 0, $length );
+		if ( strlen( $content ) > $length ) {
+			$snippet .= '...';
+		}
+		return $snippet;
+	} // end get_snippet()
+
+} // end class

WordPress/Tests/PHP/DisallowAlternativeOpenTagUnitTest.inc

@@ -0,0 +1,9 @@
+<div>
+<?php echo $var; ?>
+Some content here.
+<% echo $var; %>
+<%= echo $var . ' and some more text to make sure the snippet works'; %>
+<script language="php">
+echo $var;
+</script>
+</div>

WordPress/Tests/PHP/DisallowAlternativeOpenTagUnitTest.php

@@ -0,0 +1,77 @@
+<?php
+/**
+ * Unit test class for WordPress Coding Standard.
+ *
+ * @category PHP
+ * @package  PHP_CodeSniffer
+ * @link     https://make.wordpress.org/core/handbook/best-practices/coding-standards/
+ */
+
+/**
+ * Unit test class for the DisallowAlternativeOpenTag sniff.
+ *
+ * A sniff unit test checks a .inc file for expected violations of a single
+ * coding standard. Expected errors and warnings are stored in this class.
+ *
+ * @category PHP
+ * @package  PHP_CodeSniffer
+ * @author   Juliette Reinders Folmer <wpplugins_nospam@adviesenzo.nl>
+ */
+class WordPress_Tests_PHP_DisallowAlternativeOpenTagUnitTest extends AbstractSniffUnitTest {
+
+	/**
+	 * Returns the lines where errors should occur.
+	 *
+	 * The key of the array should represent the line number and the value
+	 * should represent the number of errors that should occur on that line.
+	 *
+	 * @return array<int, int>
+	 */
+	public function getErrorList() {
+		$asp_enabled   = (boolean) ini_get( 'asp_tags' );
+		$short_enabled = (boolean) ini_get( 'short_open_tag' );
+
+		$errors = array(
+			6 => 1,
+		);
+
+		if ( true === $asp_enabled ) {
+			$errors[4] = 1;
+		}
+		if ( true === $asp_enabled && ( true === $short_enabled || defined( 'HHVM_VERSION' ) === true ) ) {
+			$errors[5] = 1;
+		}
+
+		return $errors;
+	} // end getErrorList()
+
+	/**
+	 * Returns the lines where warnings should occur.
+	 *
+	 * The key of the array should represent the line number and the value
+	 * should represent the number of warnings that should occur on that line.
+	 *
+	 * @return array<int, int>
+	 */
+	public function getWarningList() {
+		$asp_enabled   = (boolean) ini_get( 'asp_tags' );
+		$short_enabled = (boolean) ini_get( 'short_open_tag' );
+
+		$warnings = array();
+
+		if ( false === $asp_enabled ) {
+			$warnings = array(
+				4 => 1,
+				5 => 1,
+			);
+		} elseif ( false === $short_enabled && false === defined( 'HHVM_VERSION' ) ) {
+			$warnings = array(
+				5 => 1,
+			);
+		}
+
+		return $warnings;
+
+	} // end getWarningList()
+
+} // end class