Added PSR12.Files.OpenTag to enforce that the open tag is on a line by itself when used at the start of a php-only file (ref #750)

Author: gsherwood

package.xml

@@ -73,6 +73,8 @@ http://pear.php.net/dtd/package-2.0.xsd">
     -- Enforces the order and formatting of file header blocks
   - Added PSR12.Files.ImportStatement sniff
     -- Enforces the formatting of import statements within a file
+  - Added PSR12.Files.OpenTag sniff
+    -- Enforces that the open tag is on a line by itself when used at the start of a php-only file
   - Added PSR12.Functions.ReturnTypeDeclaration sniff
     -- Enforces the formatting of return type declarations in functions and closures
   - Added PSR12.Properties.ConstantVisibility sniff
@@ -1118,6 +1120,7 @@ http://pear.php.net/dtd/package-2.0.xsd">
         <file baseinstalldir="PHP/CodeSniffer" name="DeclareStatementSniff.php" role="php" />
         <file baseinstalldir="PHP/CodeSniffer" name="FileHeaderSniff.php" role="php" />
         <file baseinstalldir="PHP/CodeSniffer" name="ImportStatementSniff.php" role="php" />
+        <file baseinstalldir="PHP/CodeSniffer" name="OpenTagSniff.php" role="php" />
        </dir>
        <dir name="Functions">
         <file baseinstalldir="PHP/CodeSniffer" name="NullableTypeDeclarationSniff.php" role="php" />
@@ -1159,6 +1162,12 @@ http://pear.php.net/dtd/package-2.0.xsd">
         <file baseinstalldir="PHP/CodeSniffer" name="FileHeaderUnitTest.php" role="test" />
         <file baseinstalldir="PHP/CodeSniffer" name="ImportStatementUnitTest.inc" role="test" />
         <file baseinstalldir="PHP/CodeSniffer" name="ImportStatementUnitTest.php" role="test" />
+        <file baseinstalldir="PHP/CodeSniffer" name="OpenTagUnitTest.1.inc" role="test" />
+        <file baseinstalldir="PHP/CodeSniffer" name="OpenTagUnitTest.2.inc" role="test" />
+        <file baseinstalldir="PHP/CodeSniffer" name="OpenTagUnitTest.2.inc.fixed" role="test" />
+        <file baseinstalldir="PHP/CodeSniffer" name="OpenTagUnitTest.3.inc" role="test" />
+        <file baseinstalldir="PHP/CodeSniffer" name="OpenTagUnitTest.4.inc" role="test" />
+        <file baseinstalldir="PHP/CodeSniffer" name="OpenTagUnitTest.php" role="test" />
        </dir>
        <dir name="Functions">
         <file baseinstalldir="PHP/CodeSniffer" name="NullableTypeDeclarationUnitTest.inc" role="test" />

phpcs.xml.dist

@@ -71,6 +71,7 @@
     <rule ref="PSR2.Classes.PropertyDeclaration"/>
     <rule ref="PSR2.Methods.MethodDeclaration"/>
     <rule ref="PSR2.Files.EndFileNewline"/>
+    <rule ref="PSR12.Files.OpenTag"/>
     <rule ref="Zend.Files.ClosingTag"/>
 
     <!-- PEAR uses warnings for inline control structures, so switch back to errors -->

src/Standards/PSR12/Sniffs/Files/OpenTagSniff.php

@@ -0,0 +1,68 @@
+<?php
+/**
+ * Checks that the open tag is defined correctly.
+ *
+ * @author    Greg Sherwood <gsherwood@squiz.net>
+ * @copyright 2006-2019 Squiz Pty Ltd (ABN 77 084 670 600)
+ * @license   https://github.com/squizlabs/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
+ */
+
+namespace PHP_CodeSniffer\Standards\PSR12\Sniffs\Files;
+
+use PHP_CodeSniffer\Sniffs\Sniff;
+use PHP_CodeSniffer\Files\File;
+
+class OpenTagSniff implements Sniff
+{
+
+
+    /**
+     * Returns an array of tokens this test wants to listen for.
+     *
+     * @return array
+     */
+    public function register()
+    {
+        return [T_OPEN_TAG];
+
+    }//end register()
+
+
+    /**
+     * Processes this sniff when one of its tokens is encountered.
+     *
+     * @param \PHP_CodeSniffer\Files\File $phpcsFile The file being scanned.
+     * @param int                         $stackPtr  The position of the current
+     *                                               token in the stack.
+     *
+     * @return void
+     */
+    public function process(File $phpcsFile, $stackPtr)
+    {
+        if ($stackPtr !== 0) {
+            // This rule only applies if the open tag is on the first line of the file.
+            return $phpcsFile->numTokens;
+        }
+
+        $next = $phpcsFile->findNext(T_INLINE_HTML, 0);
+        if ($next !== false) {
+            // This rule only applies to PHP-only files.
+            return $phpcsFile->numTokens;
+        }
+
+        $tokens = $phpcsFile->getTokens();
+        $next   = $phpcsFile->findNext(T_WHITESPACE, ($stackPtr + 1), null, true);
+        if ($tokens[$next]['line'] === $tokens[$stackPtr]['line']) {
+            $error = 'Opening PHP tag must be on a line by itself';
+            $fix   = $phpcsFile->addFixableError($error, $stackPtr, 'NotAlone');
+            if ($fix === true) {
+                $phpcsFile->fixer->addNewline($stackPtr);
+            }
+        }
+
+        return $phpcsFile->numTokens;
+
+    }//end process()
+
+
+}//end class

src/Standards/PSR12/Tests/Files/OpenTagUnitTest.1.inc

@@ -0,0 +1,3 @@
+<?php
+
+echo 'hi';

src/Standards/PSR12/Tests/Files/OpenTagUnitTest.2.inc

@@ -0,0 +1 @@
+<?php echo 'hi';

src/Standards/PSR12/Tests/Files/OpenTagUnitTest.2.inc.fixed

@@ -0,0 +1,2 @@
+<?php 
+echo 'hi';

src/Standards/PSR12/Tests/Files/OpenTagUnitTest.3.inc

@@ -0,0 +1,3 @@
+<?php echo 'hi';
+?>
+hi

src/Standards/PSR12/Tests/Files/OpenTagUnitTest.4.inc

@@ -0,0 +1,2 @@
+
+<?php echo 'hi';

src/Standards/PSR12/Tests/Files/OpenTagUnitTest.php

@@ -0,0 +1,55 @@
+<?php
+/**
+ * Unit test class for the OpenTag sniff.
+ *
+ * @author    Greg Sherwood <gsherwood@squiz.net>
+ * @copyright 2006-2019 Squiz Pty Ltd (ABN 77 084 670 600)
+ * @license   https://github.com/squizlabs/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
+ */
+
+namespace PHP_CodeSniffer\Standards\PSR12\Tests\Files;
+
+use PHP_CodeSniffer\Tests\Standards\AbstractSniffUnitTest;
+
+class OpenTagUnitTest 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.
+     *
+     * @param string $testFile The name of the file being tested.
+     *
+     * @return array<int, int>
+     */
+    public function getErrorList($testFile='')
+    {
+        switch ($testFile) {
+        case 'OpenTagUnitTest.2.inc':
+            return [1 => 1];
+        default:
+            return [];
+        }//end switch
+
+    }//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()
+    {
+        return [];
+
+    }//end getWarningList()
+
+
+}//end class