PHPCBF: fix style automatically

Install

PHPCBF arrives together with PHPCS: same Composer package, same PHAR download, same Docker image. Where phpcs only reports, phpcbf rewrites the file:

composer require --dev phpcsstandards/php_codesniffer vendor/bin/phpcbf --version

Simple auto-fix

The demo file from the previous article reported 12 errors. Ten of them carry the [x] mark — spacing, lowercase constants, header block, trailing whitespace:

phpcbf --standard=PSR12 bad.php

A TOTAL OF 10 ERRORS WERE FIXED IN 1 FILE

Re-checking shows only the two findings without the mark left: they need a human (a namespace and a camelCase rename).

Multi-line calls

Harder-looking reports fix just as mechanically. A legacy page template reported 81 errors of one family: several arguments sharing one line, and the closing parenthesis not on a line by itself:

<?php $result .= ao_card( 'ru', 'edu/literature/witcher/', '/literature/witcher_card', 'Witcher ...', 'Witcher', 'Fan art', 'Book order. Characters.', 'default_icon.png', 'reg', 'png' ) ;

ERROR | [x] Only one argument is allowed per line in a multi-line function call
ERROR | [x] Closing parenthesis of a multi-line function call must be on a line by itself

Fixed on a copy, limited to that sniff family so nothing else moves:

phpcbf --standard=PSR12 --sniffs=PSR2.Methods.FunctionCallSignature Page.php

A TOTAL OF 81 ERRORS WERE FIXED IN 1 FILE

Every call became one-argument-per-line with the bracket on its own line:

$result .= ao_card( 'ru', 'edu/literature/witcher/', '/literature/witcher_card', ... 'png' )

Prove zero change

Three checks, cheapest first. Syntax gate:

php -l Page.php

No syntax errors detected in Page.php

Plain diff shows 164 changed lines — all whitespace, but "all" is a claim. Make it a fact: compare token streams with whitespace and comments stripped. PHP executes tokens, so identical streams mean identical behaviour:

$t = token_get_all($code); // drop T_WHITESPACE, T_COMMENT, T_DOC_COMMENT, compare the rest

tokens before=2597 after=2597
IDENTICAL: semantics unchanged

2597 tokens before, 2597 after, in the same order. The fixer moved only brackets and newlines — a runtime regression is not possible here.

[x] versus [ ]

The mark decides the workflow. [x] is safe for the machine: spacing, casing of constants, header blocks, trailing whitespace, bracket placement. [ ] is always yours: camelCase renames (every caller must change too), argument order constraints, files mixing declarations with executable code.

phpcs --report=full file.php | grep -c "\[x\]"

When not to auto-fix

1. Huge diffs on stable legacy files: the fix is safe but nobody can review 164 changed lines with confidence — fix new code first.
2. Files kept byte-identical on purpose: if two copies of a template are compared byte for byte, reformatting one desyncs them. Fix the copies together or not at all.
3. Mixed findings: run the safe sniff families first (--sniffs=... limits the run), keep reformatting away from logic changes in the same commit.

Always re-run phpcs after phpcbf, review with git diff, and prove behaviour with the token comparison above whenever the diff is too large to read.

Article author: Andrei Olegovich