@christian-bromann/webdriverio/lib/scripts/createSelectorScript.js

A nodejs bindings implementation for selenium 2.0/webdriver

import findStrategy from '../helpers/findElementStrategy'

/**
 * Returns the script to execute in the browser, in string format.
 * @param {Function|String} fn - function to execute in the browser
 * @param {Array.<String>} selectors - the selectors to resolve and pass to fn, each in its own array
 * @param {Array} args - the arguments to pass to fn (after resolved selectors)
 * @param {Function} callback
 * @returns {string}
 */
let createSelectorScript = function (fn, selectors, args) {
    let strArgs = []
    let foundSel = []

    if (typeof fn === 'function' || (this.inMultibrowserMode && fn.indexOf('function (') === 0)) {
        // Handle function script
        strArgs.push(fn.toString())
    } else if (typeof fn === 'string') {
        // Handle string script
        strArgs.push(`function(){${fn}}`)
    }

    for (let selector of selectors) {
        let val = findStrategy(selector)
        foundSel.push(val.using, val.value)
    }

    strArgs.push(JSON.stringify(foundSel))

    var i = -1
    while (++i < args.length) {
        if (typeof args[i] === 'function' || (this.inMultibrowserMode && (typeof args[i] === 'string' && args[i].indexOf('function (') === 0))) {
            args[i] = args[i].toString()
        } else {
            args[i] = JSON.stringify(args[i])
        }
    }
    strArgs.push('[' + args.join(',') + ']')

    return (`return (${executeClientSide})(${strArgs.join(',')}, arguments[arguments.length - 1]);`).replace(/(\s{4}|\t)+/g, ' ')
}

/**
 * Helper that resolves selectors client side and returns the result in the given fn.
 * Every resolved selector is prepended to the function's arguments.
 * Each resolved selector yields a single array.
 *
 * @param {Function} fn - the function to execute client side that will receive the resolved selectors
 * @param {Array.<String>} sArr - a series of usage, value pairs from find-element-strategy
 * @param {Array} args - any other arguments to pass to fn
 * @returns {*} the return value of fn
 * @example
 * var helper = require('./executeClientSideSelector');
 * // Execute in the browser
 * helper(fn, ['xpath', '//body', 'css', '[id="what"]'], [1, 2, 3]);
 * // Assuming fn is...
 * fn = function(xpathResult, cssResult, one, two, three) {
 *     console.log(xpathResult.length); // 1
 *     console.log(xpathResult[0]);     // <body.../>
 *     console.log(cssResult.length);   // 0
 *     console.log(one, two, three);    // 1 2 3
 * }
 */
var executeClientSide = function (fn, sArr, args) {
    var cb = arguments[arguments.length - 1]
    var i = 0
    var sArgs = []
    var use, value, xp, cs, tn, res, j, arg

    if (typeof document.querySelectorAll === 'undefined') {
        document.querySelectorAll = function (selector) {
            var doc = document
            var head = doc.documentElement.firstChild
            var styleTag = doc.createElement('STYLE')

            head.appendChild(styleTag)
            doc.__qsaels = []

            styleTag.styleSheet.cssText = selector + '{x:expression(document.__qsaels.push(this))}'
            window.scrollBy(0, 0)

            return doc.__qsaels
        }
    }

    while ((use = sArr[i++]) && (value = sArr[i++])) {
        arg = []
        xp = cs = tn = null
        switch (use) {
        case 'partial link text':
            xp = '//a[contains(text(),"' + value + '")]'
            break
        case 'link text':
            xp = '//a[text()="' + value + '"]'
            break
        case 'xpath':
            xp = value
            break
        case 'id':
            cs = '#' + value
            break
        case 'name':
            cs = '[name="' + value + '"]'
            break
        case 'tag name':
            tn = value
            break
        case 'css selector':
            cs = value
            break
        default: throw new Error('Could not evaluate selector: Invalid strategy ' + use)
        }

        if (xp) {
            res = document.evaluate(xp, document, null, 0, null)

            value = res.iterateNext()
            while (value) {
                arg.push(value)
                value = res.iterateNext()
            }
        } else if (tn || cs) {
            res = tn ? document.getElementsByTagName(tn) : document.querySelectorAll(cs)
            for (j = 0; j < res.length; ++j) {
                arg.push(res[j])
            }
        }
        sArgs.push(arg)
    }

    var parameter = args && sArgs.concat(args) || sArgs
    if (parameter.length === 0 || (parameter.length === 1 && parameter[0].length === 0)) {
        if (typeof cb === 'function') {
            return cb('NoSuchElement') && new Error('NoSuchElement')
        }
        return new Error('NoSuchElement')
    }

    parameter.push(arguments[arguments.length - 1])

    return fn.apply(window, parameter)
}

export default createSelectorScript