Fixing Errors Automatically

Note: This documentation is for the phpcs-fixer branch only. Everything described here is still experimental.

Testing of the phpcbf command is more easily done from a Git clone rather than being installed via PEAR. If you choose to use a Git clone, use the commands /path/to/PHP_CodeSniffer/scripts/phpcs and /path/to/PHP_CodeSniffer/scripts/phpcbf instead of the ones shown in the documentation below.

PHP_CodeSniffer is able to fix many errors and warnings automatically. The diff report can be used to generate a diff that can be applied using the patch command. Alternatively, the PHP Code Beautifier and Fixer (phpcbf) can be used in place of phpcs to automatically generate and apply the diff for you.

Screen-based reports, such as the full, summary and source reports, provide information about how many errors and warnings are found. If any of the issues can be fixed automatically by phpcbf, additional information will be printed:

$ phpcs /path/to/code/myfile.php

FILE: /path/to/code/myfile.php
--------------------------------------------------------------------------------
FOUND 5 ERRORS AFFECTING 4 LINES
--------------------------------------------------------------------------------
 2 | ERROR | [ ] Missing file doc comment
 3 | ERROR | [x] TRUE, FALSE and NULL must be lowercase; expected "false" but
   |       |     found "FALSE"
 5 | ERROR | [x] Line indented incorrectly; expected at least 4 spaces, found 1
 8 | ERROR | [ ] Missing function doc comment
 8 | ERROR | [ ] Opening brace should be on a new line
--------------------------------------------------------------------------------
PHPCBF CAN FIX THE 2 MARKED SNIFF VIOLATIONS AUTOMATICALLY
--------------------------------------------------------------------------------

Printing a Diff Report

The diff report is described here as it is not currently included in the main PHPCS release. It will be moved to the Reporting page at a late date.

PHP_CodeSniffer can output a diff file that can be applied using the patch command. The suggested changes will fix some of the sniff violations that are present in the source code. To print a diff report, use the --report=diff command line argument. The output will look like this:

$ phpcs --report=diff /path/to/code

--- /path/to/code/file.php
+++ PHP_CodeSniffer
@@ -1,8 +1,8 @@
 <?php
 
-if ($foo === FALSE) {
+if ($foo === false) {
+    echo 'hi';
     echo 'hi';
- echo 'hi';
 }
 
 function foo() {

Diff reports are more easily used when output to a file. They can then be applied using the patch command:

$ phpcs --report-diff=/path/to/changes.diff /path/to/code
$ patch -p0 -ui /path/to/changes.diff
patching file /path/to/code/file.php

Using the PHP Code Beautifier and Fixer

To automatically fix as many sniff violations as possible, use the phpcbf command in place of the phpcs command. When using this command, you do not need to specify a report type. PHPCBF will automatically produce a diff file and apply it to your code using the patch command:

$ phpcbf /path/to/code
Patched 2 files
Time: 35 ms, Memory: 5.00Mb

If you do not have access to the diff or patch commands within your development environment, specify the --no-patch command line argument. PHPCBF will use PHP to replace the content of your files.

$phpcbf /path/to/code --no-patch
Fixed 2 sniff violations in /path/to/code/init.php
    => file was overwritten
Fixed 2 sniff violations in /path/to/code/main.css
    => file was overwritten
Fixed 2 files
Time: 35 ms, Memory: 5.00Mb

If you do not want to overwrite existing files, you can specify the --suffix command line argument and provide a filename suffix to use for new files. A fixed copy of each file will be created and stored in the same directory as the original file. If a file already exists with the new name, it will be overwritten.

$phpcs /path/to/code --suffix=.fixed
Fixed 2 sniff violations in /path/to/code/init.php
    => fixed file written to init.php.fixed
Fixed 2 sniff violations in /path/to/code/main.css
    => fixed file written to main.css.fixed
Fixed 2 files
Time: 35 ms, Memory: 5.00Mb

When using the --suffix command line argument, the diff and patch commands are not used so you don't need to specify the --no-patch argument.

Viewing Debug Information

To see the fixes that are being made to a file, specify the -vv command line argument. This works with both the phpcs --report=diff and phpcbf commands. There is quite a lot of debug output concerning the standard being used and the tokenizing of the file, but the end of the output will look like this:

*** START FILE FIXING ***
Generic_Sniffs_WhiteSpace_ScopeIndentSniff (line 378) replaced token 14 (T_ECHO) "echo" => "····echo"
Generic_Sniffs_PHP_LowerCaseConstantSniff (line 102) replaced token 9 (T_FALSE) "FALSE" => "false"
Fixed 2 violations, starting over
*** END FILE FIXING ***

Sometimes the file may need to be processed multiple times in order to fix all the violations. This can happen when multiple sniffs need to modify the same part of a file, or if a fix causes a new sniff violation somewhere else in the standard. When this happens, the output will look like this:

*** START FILE FIXING ***
Generic_Sniffs_WhiteSpace_ScopeIndentSniff (line 378) replaced token 14 (T_ECHO) "echo" => "····echo"
Squiz_Sniffs_Commenting_ClosingDeclarationCommentSniff (line 115) replaced token 37 (T_CLOSE_CURLY_BRACKET) "}" => "}//end·foo()\n"
Squiz_Sniffs_WhiteSpace_FunctionSpacingSniff (line 239) replaced token 26 (T_WHITESPACE) "\n" => "\n\n"
Fixed 3 violations, starting over
Squiz_Sniffs_WhiteSpace_FunctionSpacingSniff (line 132) replaced token 40 (T_COMMENT) "//end·foo()\n" => "//end·foo()\n\n\n"
Fixed 1 violations, starting over
*** END FILE FIXING ***