How to escape curly bracket "{" in TYPO3 Fluid template?

Try to use

<![CDATA[...]]>

tags around your JS code.

The CDATA solution stopped working in 8.7

I managed to solve the problem using alias in a usecase that heavily mixes javascript and fluid. {l} stands for left (open curly bracket) and {r} stands for right (close curly bracket):

<f:alias map="{l: '{', r: '}'}">
    var alter = {};
    <f:for each="{alterDB}" as="a">
        if (!alter[{a.einsatz}]) { alter[{a.einsatz}] = {}; }
        alter[{a.einsatz}][alter[{a.einsatz}].length] = {l} label: "{a.bezeichnung} ({a.kuerzel})", value: {a.uid} {r};
    </f:for>
</f:alias>

Solution working in TYPO3 9.x / 9.5.x

To avoid too much markup around curly braces which has a "not so nice" impact on the summary markup (readability and IDE support / highlighting) here an additional solution.

Possible limitation: In our case the fluid template only contained fluid template variables within the templates head section followed by the entire markup which is processed/rendered by angular.js.

So we've created a partial for the angular.js part and included those inside the main fluid template.

Example:

The included partial file now starts using a {parsing off} statement (see example below).

Partial (simplified):

{parsing off} <!-- This solved all our issues -->

<div ng-show="showSlider">
    <div class="slider" data-test="slider-wrapper">
        <div class="row">
            <div class="slide-indicator-mask col-lg-12">
                <div class="slider-scope page-{{firstSlide}}"></div>
            </div>
    </div>
</div>