Fixing Errors Automatically

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

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. While most of the PHPCS command line arguments can be used by PHPCBF, some are specific to reporting and will be ignored. Running PHPCBF with the -h or --help command line arguments will print a list of commands that PHPCBF will respond to. The output of phpcbf -h is shown below.

Usage: phpcbf [-nwli] [-d key[=value]]
    [--standard=<standard>] [--sniffs=<sniffs>] [--suffix=<suffix>]
    [--severity=<severity>] [--error-severity=<severity>] [--warning-severity=<severity>]
    [--tab-width=<tabWidth>] [--encoding=<encoding>]
    [--extensions=<extensions>] [--ignore=<patterns>] <file> ...
        -n            Do not fix warnings (shortcut for --warning-severity=0)
        -w            Fix both warnings and errors (on by default)
        -l            Local directory only, no recursion
        -i            Show a list of installed coding standards
        -d            Set the [key] php.ini value to [value] or [true] if value is omitted
        --help        Print this help message
        --version     Print version information
        --no-patch    Do not make use of the "diff" or "patch" programs
        <file>        One or more files and/or directories to fix
        <encoding>    The encoding of the files being fixed (default is iso-8859-1)
        <extensions>  A comma separated list of file extensions to fix
                      (only valid if fixing a directory)
        <patterns>    A comma separated list of patterns to ignore files and directories
        <sniffs>      A comma separated list of sniff codes to limit the fixes to
                      (all sniffs must be part of the specified standard)
        <severity>    The minimum severity required to fix an error or warning
        <standard>    The name or path of the coding standard to use
        <suffix>      Write modified files to a filename using this suffix
                      ("diff" and "patch" are not used in this mode)
        <tabWidth>    The number of spaces each tab represents

When using the PHPCBF 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
Processing init.php [PHP => 7875 tokens in 960 lines]... DONE in 274ms (12 fixable violations)
    => Fixing file: 0/12 violations remaining [made 3 passes]... DONE in 412ms
Processing config.php [PHP => 8009 tokens in 957 lines]... DONE in 421ms (155 fixable violations)
    => Fixing file: 0/155 violations remaining [made 7 passes]... DONE in 937ms
Patched 2 files
Time: 2.55 secs, Memory: 25.00Mb

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
Processing init.php [PHP => 7875 tokens in 960 lines]... DONE in 274ms (12 fixable violations)
    => Fixing file: 0/12 violations remaining [made 3 passes]... DONE in 412ms
    => File was overwritten
Processing config.php [PHP => 8009 tokens in 957 lines]... DONE in 421ms (155 fixable violations)
    => Fixing file: 0/155 violations remaining [made 7 passes]... DONE in 937ms
    => File was overwritten
Fixed 2 files
Time: 2.55 secs, Memory: 25.00Mb

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
Processing init.php [PHP => 7875 tokens in 960 lines]... DONE in 274ms (12 fixable violations)
    => Fixing file: 0/12 violations remaining [made 3 passes]... DONE in 412ms
    => Fixed file written to init.php.fixed
Processing config.php [PHP => 8009 tokens in 957 lines]... DONE in 421ms (155 fixable violations)
    => Fixing file: 0/155 violations remaining [made 7 passes]... DONE in 937ms
    => Fixed file written to config.php.fixed
Fixed 2 files
Time: 2.55 secs, Memory: 25.00Mb

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 when generating a diff report. 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:

$ phpcs /path/to/file --report=diff -vv
..snip..
*** START FILE FIXING ***
E: [Line 3] Expected 1 space after "="; 0 found (Squiz.WhiteSpace.OperatorSpacing.NoSpaceAfter)
Squiz_Sniffs_WhiteSpace_OperatorSpacingSniff (line 259) replaced token 4 (T_EQUAL) "=" => "=·"
* fixed 1 violations, starting loop 2 *
*** 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:

$ phpcs /path/to/file --report=diff -vv
..snip..
*** START FILE FIXING ***
E: [Line 3] Expected 1 space before "="; 0 found (Squiz.WhiteSpace.OperatorSpacing.NoSpaceBefore)
Squiz_Sniffs_WhiteSpace_OperatorSpacingSniff (line 228) replaced token 3 (T_EQUAL) "=" => "·="
E: [Line 3] Expected 1 space after "="; 0 found (Squiz.WhiteSpace.OperatorSpacing.NoSpaceAfter)
* token 3 has already been modified, skipping *
E: [Line 3] Equals sign not aligned correctly; expected 1 space but found 0 spaces (Generic.Formatting.MultipleStatementAlignment.Incorrect)
* token 3 has already been modified, skipping *
* fixed 1 violations, starting loop 2 *
E: [Line 3] Expected 1 space after "="; 0 found (Squiz.WhiteSpace.OperatorSpacing.NoSpaceAfter)
Squiz_Sniffs_WhiteSpace_OperatorSpacingSniff (line 259) replaced token 4 (T_EQUAL) "=" => "=·"
* fixed 1 violations, starting loop 3 *
*** END FILE FIXING ***