SimenB/stylint

'use strict'

var extendRe = /(@extend)+s?\s/


/**
 * @description check that @extend is only used with a $placeholderVar
 * @param {string} [line] curr line being linted
 * @return {boolean} true if placeholder used, false if not
 */
var placeholders = function( line ) {
    if ( line.indexOf( '@extend' ) === -1 ) { return }

    var placeholder = false

    // stylus supports multiple, mixed extends and optional extends
    // so lets pull them out of the line and check individually
    // @extends .biz !optional, $extendable !optional =>
    // ['.biz !optional', '$extendable !optional']
    var extendArr = line.replace( extendRe, '' ).split( ',' )

    // if any item in the list is not a placeholder, fail
    placeholder = extendArr.every( function( line ) {
        var trimmed = line.trim()
        return trimmed.substr( 0, 1 ) === '$'
    } )

    if ( this.state.conf === 'always' && placeholder === false ) {
        this.msg( 'always use a placeholder variable when extending' )
    }
    else if ( this.state.conf === 'never' && placeholder === true ) {
        this.msg( 'placeholder variables are disallowed' )
    }

    return placeholder
}

module.exports = placeholders