feat: Allow to enforce ellipsis instead of three dots

Our translation and design guidelines say to use ellipsis instead of three dots,
yet some code is using three dots instead of the ellipsis character.
This adds a custom fixer and rule to allow auto-fixing those strings.

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

src/Config.php

@@ -4,12 +4,23 @@
 
 namespace Nextcloud\CodingStandard;
 
+use Nextcloud\CodingStandard\Fixer\NoThreeDotsInStringFixer;
 use PhpCsFixer\Config as Base;
 
 class Config extends Base {
-	public function __construct($name = 'default') {
+
+	/**
+	 * @inheritdoc
+	 * @param bool $enableStringRules Enable rules to improve string quality
+	 */
+	public function __construct($name = 'default',
+		protected bool $enableStringRules = false,
+	) {
 		parent::__construct($name);
 		$this->setIndent("\t");
+		$this->registerCustomFixers([
+			new NoThreeDotsInStringFixer(),
+		]);
 	}
 
 	public function getRules() : array {
@@ -72,6 +83,7 @@ public function getRules() : array {
 				'elements' => ['property', 'method', 'const']
 			],
 			'yoda_style' => ['equal' => false, 'identical' => false, 'less_and_greater' => false],
+			'Nextcloud/no_three_dots_in_string' => $this->enableStringRules,
 		];
 	}
 }

src/Fixer/NoThreeDotsInStringFixer.php

@@ -0,0 +1,66 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Nextcloud\CodingStandard\Fixer;
+
+use PhpCsFixer\Fixer\FixerInterface;
+use PhpCsFixer\FixerDefinition\CodeSample;
+use PhpCsFixer\FixerDefinition\FixerDefinition;
+use PhpCsFixer\FixerDefinition\FixerDefinitionInterface;
+use PhpCsFixer\Tokenizer\Token;
+use PhpCsFixer\Tokenizer\Tokens;
+
+final class NoThreeDotsInStringFixer implements FixerInterface {
+
+	public function isCandidate(Tokens $tokens): bool {
+		return $tokens->isAnyTokenKindsFound([T_CONSTANT_ENCAPSED_STRING, T_ENCAPSED_AND_WHITESPACE]);
+	}
+
+	public function isRisky(): bool {
+		return true;
+	}
+
+	public function getName(): string {
+		return 'Nextcloud/no_three_dots_in_string';
+	}
+
+	public function getPriority(): int {
+		return 0;
+	}
+
+	public function supports(\SplFileInfo $file): bool {
+		return true;
+	}
+
+	public function getDefinition(): FixerDefinitionInterface {
+		return new FixerDefinition(
+			'There must be no three dots in strings, instead ellipsis shall be used.',
+			[
+				new CodeSample(
+					"<?php \$a = 'Loading ...';\n"
+				),
+			],
+			null,
+			'Changing the characters in strings might affect string comparisons and outputs.'
+		);
+	}
+
+	public function fix(\SplFileInfo $file, Tokens $tokens): void {
+		for ($index = $tokens->count() - 1; $index >= 0; --$index) {
+			/** @var Token $token */
+			$token = $tokens[$index];
+
+			if (!$token->isGivenKind([T_CONSTANT_ENCAPSED_STRING, T_ENCAPSED_AND_WHITESPACE])) {
+				continue;
+			}
+
+			$content = str_replace('...', '…', $token->getContent());
+			if ($token->getContent() === $content) {
+				continue;
+			}
+
+			$tokens[$index] = new Token([$tokens[$index]->getId(), $content]);
+		}
+	}
+}