1 files changed, 106 insertions, 0 deletions
diff --git a/MLEB/Translate/src/MessageValidator/Validators/GettextPluralValidator.php b/MLEB/Translate/src/MessageValidator/Validators/GettextPluralValidator.php
new file mode 100644
index 00000000..f87dff6a
--- /dev/null
+++ b/MLEB/Translate/src/MessageValidator/Validators/GettextPluralValidator.php
@@ -0,0 +1,106 @@
+<?php
+declare( strict_types = 1 );
+
+namespace MediaWiki\Extensions\Translate\MessageValidator\Validators;
+
+use MediaWiki\Extensions\Translate\Utilities\GettextPlural;
+use MediaWiki\Extensions\Translate\Validation\MessageValidator;
+use MediaWiki\Extensions\Translate\Validation\ValidationIssue;
+use MediaWiki\Extensions\Translate\Validation\ValidationIssues;
+use TMessage;
+
+/**
+ * @license GPL-2.0-or-later
+ * @since 2019.09
+ */
+class GettextPluralValidator implements MessageValidator {
+	public function getIssues( TMessage $message, string $targetLanguage ): ValidationIssues {
+		$issues = new ValidationIssues();
+
+		$pluralRule = GettextPlural::getPluralRule( $targetLanguage );
+		// Skip validation for languages for which we do not know the plural rule
+		if ( !$pluralRule ) {
+			return $issues;
+		}
+
+		$definition = $message->definition();
+		$translation = $message->translation();
+		$expectedPluralCount = GettextPlural::getPluralCount( $pluralRule );
+		$definitionHasPlural = GettextPlural::hasPlural( $definition );
+		$translationHasPlural = GettextPlural::hasPlural( $translation );
+
+		$presence = $this->pluralPresenceCheck(
+			$definitionHasPlural,
+			$translationHasPlural,
+			$expectedPluralCount
+		);
+
+		if ( $presence === 'ok' ) {
+			[ $msgcode, $data ] = $this->pluralFormCountCheck( $translation, $expectedPluralCount );
+			if ( $msgcode === 'invalid-count' ) {
+				$issue = new ValidationIssue(
+					'plural',
+					'forms',
+					'translate-checks-gettext-plural-count',
+					[
+						[ 'COUNT', $expectedPluralCount ],
+						[ 'COUNT', $data[ 'count' ] ],
+					]
+				);
+				$issues->add( $issue );
+			}
+		} elseif ( $presence === 'missing' ) {
+			$issue = new ValidationIssue(
+				'plural',
+				'missing',
+				'translate-checks-gettext-plural-missing'
+			);
+			$issues->add( $issue );
+		} elseif ( $presence === 'unsupported' ) {
+			$issue = new ValidationIssue(
+				'plural',
+				'unsupported',
+				'translate-checks-gettext-plural-unsupported'
+			);
+			$issues->add( $issue );
+		}
+		// else not-applicable: Plural is not present in translation, but that is fine
+
+		return $issues;
+	}
+
+	private function pluralPresenceCheck(
+		$definitionHasPlural,
+		$translationHasPlural,
+		$expectedPluralCount
+	) {
+		if ( !$definitionHasPlural && $translationHasPlural ) {
+			return 'unsupported';
+		} elseif ( $definitionHasPlural && !$translationHasPlural ) {
+			if ( $expectedPluralCount > 1 ) {
+				return 'missing';
+			} else {
+				// It's okay to omit plural completely for languages without variance
+				return 'not-applicable';
+			}
+		} elseif ( !$definitionHasPlural && !$translationHasPlural ) {
+			return 'not-applicable';
+		}
+
+		// Both have plural
+		return 'ok';
+	}
+
+	private function pluralFormCountCheck( $text, $expectedPluralCount ) {
+		[ , $instanceMap ] = GettextPlural::parsePluralForms( $text );
+
+		foreach ( $instanceMap as $forms ) {
+			$formsCount = count( $forms );
+			if ( $formsCount !== $expectedPluralCount ) {
+				return [ 'invalid-count', [ 'count' => $formsCount ] ];
+			}
+		}
+
+		return [ 'ok', [] ];
+	}
+}