UrlFetchApp before and after javascript - google-apps-script

Question

I have an apps script that grabs a URL and returns it's contents. I want to then search the page for a specific string, before the javascript worked on the page. Then, I want to evaluate that same page after javascript has done it's thing.
The reason is that I have a 3rd-party script that replaces phone numbers on the page, based on region. I want to evaluate the original, before javascript source, to see if one of the replaceable numbers exists. If it does, I want check the after-javascript version to verify if it's been replaced with a number from that region.
I can do this manually by choosing "View Source" in the browser, then checking the Inspect Element where that string was found.
My problem is that I can't get the original source from UrlFetchApp. Is there a way to do that?
Thanks in advance,
Hans
--
Code
var doc = UrlFetchApp.fetch(url).getContentText();
// doc is the after-javascript version...

Answer 1

I just ran a test on an example website and found that UrlFetchApp does return the original source before JS rendering. I believe .fetch() works like a standard HTTP GET request, so I don't see why this wouldn't be the case.
Example: https://tutorialzine.com/2015/02/single-page-app-without-a-framework
UrlFetchApp Result Snippet:
<ul class="products-list">
<script id="products-template" type="x-handlebars-template">
{{#each this}}
<li data-index="{{id}}">
<img src="{{image.small}}" height="130" alt="{{name}}"/>
<h2> {{name}} </h2>
<ul class="product-description">
<li><span>Manufacturer: </span>{{specs.manufacturer}}</li>
<li><span>Storage: </span>{{specs.storage}} GB</li>
<li><span>OS: </span>{{specs.os}}</li>
<li><span>Camera: </span>{{specs.camera}} Mpx</li>
</ul>
<button>Buy Now!</button>
<p class="product-price">{{price}}$</p>
<div class="highlight"></div>
</li>
{{/each}}
</script>
</ul>
Post-JS Render Result:
<ul class="products-list">
<script id="products-template" type="x-handlebars-template">
​
{{#each this}}
<li data-index="{{id}}">
<img src="{{image.small}}" height="130" alt="{{name}}"/>
<h2> {{name}} </h2>
<ul class="product-description">
<li><span>Manufacturer: </span>{{specs.manufacturer}}</li>
<li><span>Storage: </span>{{specs.storage}} GB</li>
<li><span>OS: </span>{{specs.os}}</li>
<li><span>Camera: </span>{{specs.camera}} Mpx</li>
</ul>
<button>Buy Now!</button>
<p class="product-price">{{price}}$</p>
<div class="highlight"></div>
</li>
{{/each}}
</script>
​
<li data-index="1" class="">
<a href="#" class="product-photo"
><img
src="assets/images/sony-xperia-z3.jpg"
height="130"
alt="Sony Xperia Z3"
/></a>
<h2> Sony Xperia Z3 </h2>
<ul class="product-description">
<li><span>Manufacturer: </span>Sony</li>
<li><span>Storage: </span>16 GB</li>
<li><span>OS: </span>Android</li>
<li><span>Camera: </span>15 Mpx</li>
</ul>
<button>Buy Now!</button>
<p class="product-price">899$</p>
<div class="highlight"></div>
</li>
<li data-index="2" class="">
<a href="#" class="product-photo"
><img src="assets/images/iphone6.jpg" height="130" alt="Iphone 6"
/></a>
<h2> Iphone 6 </h2>
<ul class="product-description">
<li><span>Manufacturer: </span>Apple</li>
<li><span>Storage: </span>16 GB</li>
<li><span>OS: </span>iOS</li>
<li><span>Camera: </span>8 Mpx</li>
</ul>
<button>Buy Now!</button>
<p class="product-price">899$</p>
<div class="highlight"></div>
</li>
<li data-index="3" class="">
<a href="#" class="product-photo"
><img src="assets/images/htc-one.jpg" height="130" alt="HTC One M8"
/></a>
<h2> HTC One M8 </h2>
<ul class="product-description">
<li><span>Manufacturer: </span>HTC</li>
<li><span>Storage: </span>32 GB</li>
<li><span>OS: </span>Android</li>
<li><span>Camera: </span>5 Mpx</li>
</ul>
<button>Buy Now!</button>
<p class="product-price">899$</p>
<div class="highlight"></div>
</li>
<li data-index="4" class="">
<a href="#" class="product-photo"
><img
src="assets/images/galaxy-alpha.jpg"
height="130"
alt="Galaxy Alpha"
/></a>
<h2> Galaxy Alpha </h2>
<ul class="product-description">
<li><span>Manufacturer: </span>Samsung</li>
<li><span>Storage: </span>32 GB</li>
<li><span>OS: </span>Android</li>
<li><span>Camera: </span>12 Mpx</li>
</ul>
<button>Buy Now!</button>
<p class="product-price">899$</p>
<div class="highlight"></div>
</li>
<li data-index="5" class="">
<a href="#" class="product-photo"
><img
src="assets/images/nokia-lumia.jpg"
height="130"
alt="Nokia Lumia"
/></a>
<h2> Nokia Lumia </h2>
<ul class="product-description">
<li><span>Manufacturer: </span>Nokia</li>
<li><span>Storage: </span>16 GB</li>
<li><span>OS: </span>Windows</li>
<li><span>Camera: </span>5 Mpx</li>
</ul>
<button>Buy Now!</button>
<p class="product-price">450$</p>
<div class="highlight"></div>
</li>
<li data-index="6" class="">
<a href="#" class="product-photo"
><img src="assets/images/zte-nubia.jpg" height="130" alt="Zte Nubia"
/></a>
<h2> Zte Nubia </h2>
<ul class="product-description">
<li><span>Manufacturer: </span>ZTE</li>
<li><span>Storage: </span>32 GB</li>
<li><span>OS: </span>Android</li>
<li><span>Camera: </span>12 Mpx</li>
</ul>
<button>Buy Now!</button>
<p class="product-price">399$</p>
<div class="highlight"></div>
</li>
<li data-index="7" class="">
<a href="#" class="product-photo"
><img
src="assets/images/galaxy-s5.jpg"
height="130"
alt="Samsung Galaxy S5"
/></a>
<h2> Samsung Galaxy S5 </h2>
<ul class="product-description">
<li><span>Manufacturer: </span>Samsung</li>
<li><span>Storage: </span>16 GB</li>
<li><span>OS: </span>Android</li>
<li><span>Camera: </span>15 Mpx</li>
</ul>
<button>Buy Now!</button>
<p class="product-price">399$</p>
<div class="highlight"></div>
</li>
<li data-index="8" class="">
<a href="#" class="product-photo"
><img src="assets/images/iphone5s.jpg" height="130" alt="Iphone 5S"
/></a>
<h2> Iphone 5S </h2>
<ul class="product-description">
<li><span>Manufacturer: </span>Apple</li>
<li><span>Storage: </span>16 GB</li>
<li><span>OS: </span>iOS</li>
<li><span>Camera: </span>8 Mpx</li>
</ul>
<button>Buy Now!</button>
<p class="product-price">399$</p>
<div class="highlight"></div>
</li>
</ul>