Introduce SingleQuoteRule (#212)

docs/rules.md

@@ -11,6 +11,7 @@
 - **OperatorSpacingRule**: ensures there is one space before and after an operator except for `..`.
 - **PunctuationSpacingRule**: ensures there is no space before and after a punctuation except for `:` and `,` (configurable).
 - **TrailingCommaSingleLineRule**: ensures that single-line arrays, objects and argument lists do not have a trailing comma.
+- **SingleQuoteRule**: ensures that strings use single quotes when possible (configurable).
 - **BlankEOFRule**: ensures that files ends with one blank line.
 - **EmptyLinesRule**: ensures that 2 empty lines do not follow each other.
 - **IndentRule**: ensures that files are not indented with tabs (configurable).
@@ -55,6 +56,7 @@ new TwigCsFixer\Rules\Whitespace\IndentRule(3);
 - BlockNameSpacingRule
 - EmptyLinesRule
 - IndentRule
+- SingleQuoteRule
 - TrailingCommaSingleLineRule
 - TrailingSpaceRule
 

src/Rules/String/SingleQuoteRule.php

@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TwigCsFixer\Rules\String;
+
+use TwigCsFixer\Rules\AbstractFixableRule;
+use TwigCsFixer\Rules\ConfigurableRuleInterface;
+use TwigCsFixer\Token\Token;
+
+/**
+ * Ensures that strings use single quotes when possible.
+ */
+final class SingleQuoteRule extends AbstractFixableRule implements ConfigurableRuleInterface
+{
+    public function __construct(private bool $skipStringContainingSingleQuote = true)
+    {
+    }
+
+    public function getConfiguration(): array
+    {
+        return [
+            'skip_string_containing_single_quote' => $this->skipStringContainingSingleQuote,
+        ];
+    }
+
+    protected function process(int $tokenPosition, array $tokens): void
+    {
+        $token = $tokens[$tokenPosition];
+        if (!$this->isTokenMatching($token, Token::STRING_TYPE)) {
+            return;
+        }
+
+        $content = $token->getValue();
+        if (
+            !str_starts_with($content, '"')
+            || str_contains($content, '\'') && $this->skipStringContainingSingleQuote
+        ) {
+            return;
+        }
+
+        $fixer = $this->addFixableError('String should be declared with single quotes.', $token);
+        if (null === $fixer) {
+            return;
+        }
+
+        $content = substr($content, 1, -1);
+        $content = str_replace(
+            ['\\"', '\\#{', '#\\{', '\\\'', '\''],
+            ['"', '#{', '#{', '\'', '\\\''],
+            $content
+        );
+        $fixer->replaceToken($tokenPosition, '\''.$content.'\'');
+    }
+}

src/Standard/TwigCsFixer.php

@@ -6,6 +6,7 @@
 
 use TwigCsFixer\Rules\Delimiter\BlockNameSpacingRule;
 use TwigCsFixer\Rules\Punctuation\TrailingCommaSingleLineRule;
+use TwigCsFixer\Rules\String\SingleQuoteRule;
 use TwigCsFixer\Rules\Whitespace\BlankEOFRule;
 use TwigCsFixer\Rules\Whitespace\EmptyLinesRule;
 use TwigCsFixer\Rules\Whitespace\IndentRule;
@@ -24,6 +25,7 @@ public function getRules(): array
             new BlockNameSpacingRule(),
             new EmptyLinesRule(),
             new IndentRule(),
+            new SingleQuoteRule(),
             new TrailingCommaSingleLineRule(),
             new TrailingSpaceRule(),
         ];

tests/Rules/String/SimpleQuote/SingleQuoteRuleTest.all.fixed.twig

@@ -0,0 +1,11 @@
+'foo'
+"foo"
+
+{% set foo = 'foo' %}
+{% set foo2 = 'foo' %}
+{% set foo3 = '\'foo\'' %}
+{% set foo4 = '\'foo\'' %}
+
+{% set foo5 = "#{p.first}" %}
+{% set foo6 = '#{p.first}' %}
+{% set foo7 = '#{p.first}' %}

tests/Rules/String/SimpleQuote/SingleQuoteRuleTest.fixed.twig

@@ -0,0 +1,11 @@
+'foo'
+"foo"
+
+{% set foo = 'foo' %}
+{% set foo2 = 'foo' %}
+{% set foo3 = "'foo'" %}
+{% set foo4 = "\'foo\'" %}
+
+{% set foo5 = "#{p.first}" %}
+{% set foo6 = '#{p.first}' %}
+{% set foo7 = '#{p.first}' %}

tests/Rules/String/SimpleQuote/SingleQuoteRuleTest.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TwigCsFixer\Tests\Rules\String\SimpleQuote;
+
+use TwigCsFixer\Rules\String\SingleQuoteRule;
+use TwigCsFixer\Tests\Rules\AbstractRuleTestCase;
+
+class SingleQuoteRuleTest extends AbstractRuleTestCase
+{
+    public function testConfiguration(): void
+    {
+        static::assertSame(
+            ['skip_string_containing_single_quote' => true],
+            (new SingleQuoteRule())->getConfiguration()
+        );
+        static::assertSame(
+            ['skip_string_containing_single_quote' => false],
+            (new SingleQuoteRule(false))->getConfiguration()
+        );
+    }
+
+    public function testRule(): void
+    {
+        $this->checkRule(new SingleQuoteRule(), [
+            'SingleQuote.Error:5:15' => 'String should be declared with single quotes.',
+            'SingleQuote.Error:10:15' => 'String should be declared with single quotes.',
+            'SingleQuote.Error:11:15' => 'String should be declared with single quotes.',
+        ]);
+    }
+
+    public function testRuleWithoutSkippingSingleQuote(): void
+    {
+        $this->checkRule(new SingleQuoteRule(false), [
+            'SingleQuote.Error:5:15' => 'String should be declared with single quotes.',
+            'SingleQuote.Error:6:15' => 'String should be declared with single quotes.',
+            'SingleQuote.Error:7:15' => 'String should be declared with single quotes.',
+            'SingleQuote.Error:10:15' => 'String should be declared with single quotes.',
+            'SingleQuote.Error:11:15' => 'String should be declared with single quotes.',
+        ], fixedFilePath: __DIR__.'/SingleQuoteRuleTest.all.fixed.twig');
+    }
+}

tests/Rules/String/SimpleQuote/SingleQuoteRuleTest.twig

@@ -0,0 +1,11 @@
+'foo'
+"foo"
+
+{% set foo = 'foo' %}
+{% set foo2 = "foo" %}
+{% set foo3 = "'foo'" %}
+{% set foo4 = "\'foo\'" %}
+
+{% set foo5 = "#{p.first}" %}
+{% set foo6 = "\#{p.first}" %}
+{% set foo7 = "#\{p.first}" %}

tests/Standard/TwigCsFixerTest.php

@@ -11,6 +11,7 @@
 use TwigCsFixer\Rules\Operator\OperatorSpacingRule;
 use TwigCsFixer\Rules\Punctuation\PunctuationSpacingRule;
 use TwigCsFixer\Rules\Punctuation\TrailingCommaSingleLineRule;
+use TwigCsFixer\Rules\String\SingleQuoteRule;
 use TwigCsFixer\Rules\Variable\VariableNameRule;
 use TwigCsFixer\Rules\Whitespace\BlankEOFRule;
 use TwigCsFixer\Rules\Whitespace\EmptyLinesRule;
@@ -34,6 +35,7 @@ public function testGetRules(): void
             new BlockNameSpacingRule(),
             new EmptyLinesRule(),
             new IndentRule(),
+            new SingleQuoteRule(),
             new TrailingCommaSingleLineRule(),
             new TrailingSpaceRule(),
         ], $standard->getRules());