wp-calypso/packages/eslint-plugin-wpcalypso/lib/rules/i18n-mismatched-placeholders.js

/**
 * @file Ensure placeholder counts match between singular and plural strings
 * @author Automattic
 * @copyright 2016 Automattic. All rights reserved.
 * See LICENSE.md file in root directory for full license.
 */

//------------------------------------------------------------------------------
// Constants
//------------------------------------------------------------------------------

// Regular expression adapted from sprintf.js. See CREDITS.md for license information.
const RX_PLACEHOLDERS =
	/(?:\x25\x25)|(\x25(?:(?:[1-9]\d*)\$|\((?:[^)]+)\))?(?:\+)?(?:0|'[^$])?(?:-)?(?:\d+)?(?:\.(?:\d+))?(?:[b-fiosuxX]))/g; // eslint-disable-line max-len

//------------------------------------------------------------------------------
// Helper Functions
//------------------------------------------------------------------------------

const getCallee = require( '../util/get-callee' );
const getTextContentFromNode = require( '../util/get-text-content-from-node' );

//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------

const rule = ( module.exports = function ( context ) {
	return {
		CallExpression: function ( node ) {
			if ( 'translate' !== getCallee( node ).name ) {
				return;
			}

			// Only consider translate calls with plurals specified
			if ( node.arguments.length !== 3 ) {
				return;
			}

			const singular = getTextContentFromNode( node.arguments[ 0 ] );
			const plural = getTextContentFromNode( node.arguments[ 1 ] );

			// Ignore invalid arguments
			if ( 'string' !== typeof singular || 'string' !== typeof plural ) {
				return;
			}

			const singularMatch = singular.match( RX_PLACEHOLDERS );
			const pluralMatch = plural.match( RX_PLACEHOLDERS );

			// Ignore strings without any placeholders
			if ( ! singularMatch && ! pluralMatch ) {
				return;
			}

			if (
				( singularMatch && ! pluralMatch ) ||
				( ! singularMatch && pluralMatch ) ||
				singularMatch.length !== pluralMatch.length
			) {
				context.report( node, rule.ERROR_MESSAGE );
			}
		},
	};
} );

rule.ERROR_MESSAGE = 'Should have same number of placeholders between singular and plural';

rule.schema = [];