Trapped in ES5

One of the platforms that I develop and maintain for my current employer is the LG SmartTV App, and the oldest TV version we support is the LG TV with webOS 3.5. Most of the TVs with this OS were released in 2017, but the OS itself is based on Chromium 38, which was released in August 2014, around three years earlier.

Everything is fine since we transpile our code into ES5 using Babel. However, when I needed to update the legacy scripts inside index.html that were not transpiled, something surprised me.

I added a default parameter to a JavaScript function, but it made the app unable to run on that webOS version. I realized that a default parameter is part of ES6 and was only available since Chromium 49. Luckily, we managed to fix that before it was released to production.

It’s funny; I thought that feature had already been available for a long time, but apparently, the OS couldn’t handle it. As a programmer who has been coding JavaScript before the ES6 existence, I had already forgotten the excitement when welcoming the ES6 features, so I thought it was released a decade ago. Thanks to, we can always check the browser/engine support.

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