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Add NoUselessStrlenFixer (#335)
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‎CHANGELOG.md‎

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## v2.3.0 - [Unreleased]
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- Add NoUselessParenthesisFixer
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- Add NoUselessStrlenFixer
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## v2.2.0 - *2020-04-02*
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- Feature: DataProviderNameFixer - add options "prefix" and "suffix"

‎README.md‎

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[![CI Status](https://github.com/kubawerlos/php-cs-fixer-custom-fixers/workflows/CI/badge.svg?branch=master&event=push)](https://github.com/kubawerlos/php-cs-fixer-custom-fixers/actions)
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[![Code coverage](https://img.shields.io/coveralls/github/kubawerlos/php-cs-fixer-custom-fixers/master.svg)](https://coveralls.io/github/kubawerlos/php-cs-fixer-custom-fixers?branch=master)
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![Tests](https://img.shields.io/badge/tests-2248-brightgreen.svg)
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![Tests](https://img.shields.io/badge/tests-2291-brightgreen.svg)
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[![Mutation testing badge](https://badge.stryker-mutator.io/github.com/kubawerlos/php-cs-fixer-custom-fixers/master)](https://stryker-mutator.github.io)
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[![Psalm type coverage](https://shepherd.dev/github/kubawerlos/php-cs-fixer-custom-fixers/coverage.svg)](https://shepherd.dev/github/kubawerlos/php-cs-fixer-custom-fixers)
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@@ -288,6 +288,17 @@ Function `sprintf` without parameters should not be used.
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+$foo = 'Foo';
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```
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#### NoUselessStrlenFixer
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Function `strlen` should not be used when compared to 0.
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*Risky: when the function `strlen` is overridden.*
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```diff
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<?php
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-$isEmpty = strlen($string) === 0;
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-$isNotEmpty = strlen($string) > 0;
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+$isEmpty = $string === '';
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+$isNotEmpty = $string !== '';
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```
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#### NumericLiteralSeparatorFixer
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Numeric literals must have configured separators.
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Configuration options:

‎src/Fixer/NoUselessStrlenFixer.php‎

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<?php
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declare(strict_types=1);
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/*
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* This file is part of PHP CS Fixer: custom fixers.
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*
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* (c) 2018-2020 Kuba Werłos
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*
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* For the full copyright and license information, please view
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* the LICENSE file that was distributed with this source code.
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*/
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namespace PhpCsFixerCustomFixers\Fixer;
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use PhpCsFixer\FixerDefinition\CodeSample;
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use PhpCsFixer\FixerDefinition\FixerDefinition;
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use PhpCsFixer\FixerDefinition\FixerDefinitionInterface;
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use PhpCsFixer\Tokenizer\Analyzer\ArgumentsAnalyzer;
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use PhpCsFixer\Tokenizer\Analyzer\FunctionsAnalyzer;
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use PhpCsFixer\Tokenizer\Token;
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use PhpCsFixer\Tokenizer\Tokens;
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final class NoUselessStrlenFixer extends AbstractFixer
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{
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public function getDefinition(): FixerDefinitionInterface
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{
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return new FixerDefinition(
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'Function `strlen` should not be used when compared to 0.',
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[
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new CodeSample(
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'<?php
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$isEmpty = strlen($string) === 0;
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$isNotEmpty = strlen($string) > 0;
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'
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),
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],
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null,
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'when the function `strlen` is overridden'
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);
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}
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public function getPriority(): int
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{
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return 0;
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}
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public function isCandidate(Tokens $tokens): bool
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{
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return $tokens->isTokenKindFound(T_LNUMBER) && $tokens->isAnyTokenKindsFound(['>', '<', T_IS_IDENTICAL, T_IS_NOT_IDENTICAL, T_IS_EQUAL, T_IS_NOT_EQUAL]);
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}
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public function isRisky(): bool
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{
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return true;
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}
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public function fix(\SplFileInfo $file, Tokens $tokens): void
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{
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$argumentsAnalyzer = new ArgumentsAnalyzer();
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$functionsAnalyzer = new FunctionsAnalyzer();
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for ($index = $tokens->count() - 1; $index > 0; $index--) {
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/** @var Token $token */
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$token = $tokens[$index];
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if (!$token->equalsAny([[T_STRING, 'strlen'], [T_STRING, 'mb_strlen']], false)) {
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continue;
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}
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if (!$functionsAnalyzer->isGlobalFunctionCall($tokens, $index)) {
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continue;
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}
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/** @var int $openParenthesisIndex */
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$openParenthesisIndex = $tokens->getNextTokenOfKind($index, ['(']);
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$closeParenthesisIndex = $tokens->findBlockEnd(Tokens::BLOCK_TYPE_PARENTHESIS_BRACE, $openParenthesisIndex);
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if ($argumentsAnalyzer->countArguments($tokens, $openParenthesisIndex, $closeParenthesisIndex) !== 1) {
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continue;
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}
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$tokensToRemove = [
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$index => 1,
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$openParenthesisIndex => 1,
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$closeParenthesisIndex => -1,
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];
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/** @var int $prevIndex */
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$prevIndex = $tokens->getPrevMeaningfulToken($index);
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/** @var Token $prevToken */
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$prevToken = $tokens[$prevIndex];
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$startIndex = $index;
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if ($prevToken->isGivenKind(T_NS_SEPARATOR)) {
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$startIndex = $prevIndex;
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$tokensToRemove[$prevIndex] = 1;
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}
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if (!$this->transformCondition($tokens, $startIndex, $closeParenthesisIndex)) {
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continue;
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}
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$this->removeTokenAndSiblingWhitespace($tokens, $tokensToRemove);
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}
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}
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private function transformCondition(Tokens $tokens, int $startIndex, int $endIndex): bool
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{
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if ($this->transformConditionLeft($tokens, $startIndex)) {
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return true;
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}
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if ($this->transformConditionRight($tokens, $endIndex)) {
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return true;
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}
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return false;
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}
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private function transformConditionLeft(Tokens $tokens, int $index): bool
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{
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/** @var int $prevIndex */
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$prevIndex = $tokens->getPrevMeaningfulToken($index);
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/** @var Token $prevToken */
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$prevToken = $tokens[$prevIndex];
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$changeCondition = false;
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if ($prevToken->equals('<')) {
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$changeCondition = true;
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} elseif (!$prevToken->isGivenKind([T_IS_IDENTICAL, T_IS_NOT_IDENTICAL, T_IS_EQUAL, T_IS_NOT_EQUAL])) {
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return false;
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}
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/** @var int $prevPrevIndex */
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$prevPrevIndex = $tokens->getPrevMeaningfulToken($prevIndex);
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/** @var Token $prevPrevToken */
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$prevPrevToken = $tokens[$prevPrevIndex];
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if (!$prevPrevToken->equals([T_LNUMBER, '0'])) {
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return false;
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}
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if ($changeCondition) {
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$tokens[$prevIndex] = new Token([T_IS_NOT_IDENTICAL, '!==']);
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}
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$tokens[$prevPrevIndex] = new Token([T_CONSTANT_ENCAPSED_STRING, '\'\'']);
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return true;
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}
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private function transformConditionRight(Tokens $tokens, int $index): bool
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{
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/** @var int $nextIndex */
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$nextIndex = $tokens->getNextMeaningfulToken($index);
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/** @var Token $nextToken */
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$nextToken = $tokens[$nextIndex];
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$changeCondition = false;
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if ($nextToken->equals('>')) {
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$changeCondition = true;
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} elseif (!$nextToken->isGivenKind([T_IS_IDENTICAL, T_IS_NOT_IDENTICAL, T_IS_EQUAL, T_IS_NOT_EQUAL])) {
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return false;
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}
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/** @var int $nextNextIndex */
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$nextNextIndex = $tokens->getNextMeaningfulToken($nextIndex);
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/** @var Token $nextNextToken */
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$nextNextToken = $tokens[$nextNextIndex];
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if (!$nextNextToken->equals([T_LNUMBER, '0'])) {
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return false;
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}
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if ($changeCondition) {
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$tokens[$nextIndex] = new Token([T_IS_NOT_IDENTICAL, '!==']);
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}
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$tokens[$nextNextIndex] = new Token([T_CONSTANT_ENCAPSED_STRING, '\'\'']);
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return true;
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}
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/**
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* @param array<int, int> $tokensToRemove
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*/
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private function removeTokenAndSiblingWhitespace(Tokens $tokens, array $tokensToRemove): void
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{
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foreach ($tokensToRemove as $index => $direction) {
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$tokens->clearAt($index);
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/** @var Token $siblingToken */
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$siblingToken = $tokens[$index + $direction];
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if ($siblingToken->isWhitespace()) {
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$tokens->clearAt($index + $direction);
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}
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}
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}
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}

‎tests/Fixer/NoUselessStrlenFixerTest.php‎

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<?php
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declare(strict_types=1);
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/*
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* This file is part of PHP CS Fixer: custom fixers.
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*
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* (c) 2018-2020 Kuba Werłos
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*
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* For the full copyright and license information, please view
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* the LICENSE file that was distributed with this source code.
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*/
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namespace Tests\Fixer;
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/**
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* @internal
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*
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* @covers \PhpCsFixerCustomFixers\Fixer\NoUselessStrlenFixer
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*/
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final class NoUselessStrlenFixerTest extends AbstractFixerTestCase
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{
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public function testIsRisky(): void
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{
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self::assertTrue($this->fixer->isRisky());
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}
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/**
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* @dataProvider provideFixCases
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*/
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public function testFix(string $expected, ?string $input = null): void
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{
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$this->doTest($expected, $input);
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}
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public static function provideFixCases(): iterable
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{
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yield ['<?php Foo\strlen($s) > 0;'];
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yield ['<?php strsize($s) > 0;'];
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yield ['<?php strlen($s) > 1;'];
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yield ['<?php 1 < strlen($s);'];
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yield ['<?php strlen() > 0;'];
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yield ['<?php strlen($a, $b) > 0;'];
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yield ['<?php $s !== \'\';', '<?php strlen($s) > 0;'];
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yield ['<?php $s === \'\';', '<?php strlen($s) === 0;'];
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yield ['<?php $s == \'\';', '<?php strlen($s) == 0;'];
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yield ['<?php $s !== \'\';', '<?php strlen($s) !== 0;'];
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yield ['<?php $s != \'\';', '<?php strlen($s) != 0;'];
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yield ['<?php \'\' !== $s;', '<?php 0 < strlen($s);'];
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yield ['<?php \'\' === $s;', '<?php 0 === strlen($s);'];
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yield ['<?php \'\' == $s;', '<?php 0 == strlen($s);'];
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yield ['<?php \'\' !== $s;', '<?php 0 !== \strlen($s);'];
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yield ['<?php \'\' != $s;', '<?php 0 != \strlen($s);'];
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yield ['<?php $s !== \'\';', '<?php \strlen($s) > 0;'];
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yield ['<?php $s !== \'\';', '<?php mb_strlen($s) > 0;'];
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yield ['<?php $s !== \'\';', '<?php StrLen($s) > 0;'];
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yield ['<?php $s !== \'\';', '<?php MB_strlen($s) > 0;'];
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yield ['<?php $s !== \'\';', '<?php \mb_strlen($s) > 0;'];
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yield ['<?php $s !== \'\';', '<?php strlen ( $s ) > 0;'];
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yield [
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'<?php
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$a !== \'\';
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Foo\strlen($a) > 0;
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strlen($a) > 1;
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strlen($a, $b) > 0;
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$a !== \'\';
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',
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'<?php
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strlen($a) > 0;
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Foo\strlen($a) > 0;
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strlen($a) > 1;
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strlen($a, $b) > 0;
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strlen($a) > 0;
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',
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];
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}
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}

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