Added check to make sure the file header is the first thing in the fi…

…le (ref squizlabs#750)

package.xml

@@ -1155,6 +1155,7 @@ http://pear.php.net/dtd/package-2.0.xsd">
         <file baseinstalldir="PHP/CodeSniffer" name="FileHeaderUnitTest.3.inc" role="test" />
         <file baseinstalldir="PHP/CodeSniffer" name="FileHeaderUnitTest.4.inc" role="test" />
         <file baseinstalldir="PHP/CodeSniffer" name="FileHeaderUnitTest.4.inc.fixed" role="test" />
+        <file baseinstalldir="PHP/CodeSniffer" name="FileHeaderUnitTest.5.inc" role="test" />
         <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" />

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

@@ -130,6 +130,13 @@ public function process(File $phpcsFile, $stackPtr)
             $next = $phpcsFile->findNext(T_WHITESPACE, ($next + 1), null, true);
         } while ($next !== false);
 
+        if (count($headerLines) === 1) {
+            // This is only an open tag and doesn't contain the file header.
+            // We need to keep checking for one in case they put it further
+            // down in the file.
+            return;
+        }
+
         /*
             Next, check the spacing and grouping of the statements
             inside each header block.
@@ -213,7 +220,7 @@ public function process(File $phpcsFile, $stackPtr)
         }//end foreach
 
         /*
-            Finally, check that the order of the header blocks
+            Next, check that the order of the header blocks
             is correct:
                 Opening php tag.
                 File-level docblock.
@@ -269,6 +276,18 @@ public function process(File $phpcsFile, $stackPtr)
             }//end if
         }//end foreach
 
+        /*
+            Finally, make sure this header block is at the very
+            top of the file.
+        */
+
+        if ($stackPtr !== 0) {
+            $error = 'The file header must be the first content in the file';
+            $phpcsFile->addError($error, $stackPtr, 'HeaderPosition');
+        }
+
+        return $phpcsFile->numTokens;
+
     }//end process()
 
 

src/Standards/PSR12/Tests/Files/FileHeaderUnitTest.5.inc

@@ -0,0 +1,18 @@
+<?php
+    echo 'Some content';
+?>
+<?php
+
+/**
+ * The header is not the first thing in the file.
+ */
+
+namespace Vendor\Package;
+
+/**
+ * FooBar is an example class.
+ */
+class FooBar
+{
+    // ... additional PHP code ...
+}

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

@@ -48,6 +48,8 @@ public function getErrorList($testFile='')
                 3 => 1,
                 7 => 1,
             ];
+        case 'FileHeaderUnitTest.5.inc':
+            return [4 => 1];
         default:
             return [];
         }//end switch