wikimedia/mediawiki-extensions-MobileFrontend

const util = require( './util' ),
    actionParams = require( './actionParams.js' );

/**
 * Extends the API query parameters to include those parameters required to also fetch Wikibase
 * descriptions and appropriately sized thumbnail images as well as those required to make a query.
 *
 * This function wraps `util.extend` with some Wikibase-specific configuration
 * variable management
 * but, like `util.extend`, is variadic and so can be used as a replacement for it in search
 * gateways, e.g.
 *
 * ```
 * var params = extendSearchParams(
 *   'search',
 *   baseParams,
 *   specializedParams,
 *   moreSpecializedParams
 * );
 * ```
 *
 * @param {string} feature The name of the feature
 * @throws {Error} If `feature` isn't one that shows Wikidata descriptions. See the
 *  `wgMFDisplayWikibaseDescriptions` configuration variable for detail
 * @return {Object}
 */
module.exports = function extendSearchParams( feature ) {
    const displayWikibaseDescriptions = mw.config.get( 'wgMFDisplayWikibaseDescriptions' ) || {
            // These must be defined, as these are all the features that this can be used on.
            // If not defined, all these features will see their API calls broken
            search: true,
            watchlist: true,
            tagline: false
        },
        scriptPath = mw.config.get( 'wgMFScriptPath' );

    if ( !Object.prototype.hasOwnProperty.call( displayWikibaseDescriptions, feature ) ) {
        throw new Error( '"' + feature + '" isn\'t a feature that shows Wikibase descriptions.' );
    }

    // Construct the arguments for a call to `util.extend`
    // such that if it were hand-written, then it
    // would look like the following:
    //
    // ```
    // var result = util.extend( {
    //   prop: []
    // }, params, /* ..., */ mw.config.get( 'wgMFSearchAPIParams' ) );
    // ```
    const args = Array.prototype.slice.call( arguments, 1 );
    args.unshift( {
        prop: []
    } );
    args.push( mw.config.get( 'wgMFSearchAPIParams' ) );

    const result = util.extend.apply( {}, args );
    result.prop = result.prop.concat( mw.config.get( 'wgMFQueryPropModules' ) );

    if ( displayWikibaseDescriptions[feature] ) {
        if ( result.prop.indexOf( 'description' ) === -1 ) {
            result.prop.push( 'description' );
        }
    }

    if ( scriptPath ) {
        // A foreign api is being accessed! Enable anonymous CORS queries!
        result.origin = '*';
    }
    return actionParams( result );
};