Feature Request: Feature Check

[calinoracation]

Hey folks! I'm trying to understand what feature https://assets5.lottiefiles.com/private_files/lf30_deoivojd.json is using that is causing it to not only not load correctly, but throw an error trying to load it on the console and blow up.

I know a number of folks run into this with jLottie having an incomplete feature set currently, including our motion designers. Having a debug mode that can look at a json asset, and print out to the console or some other mechanism any features in use that are not supported would be super helpful. In this instance, I am assuming the above asset is using Merge Paths, but without a long cycle of reaching out to our designer and having them look through the After Effects file, it's a challenge to understand why something doesn't work.

If a feature existed that even though it's not implemented, would report the features in use that are not supported, I think that would be super helpful not just to engineers, but also motion designers trying to make their art work with jLottie.

Potential Output:

The asset could not be fully loaded as it makes use of the following currently unsupported features:
  - Merge Paths
  - Expressions

Some of these issues can be worked around by following the steps at http://some_url_with_tips.

Current Output:

jlottie.js:1266 Error: <rect> attribute width: Expected length, "[object Object]".
I @ jlottie.js:1266
jlottie.js:1267 Error: <rect> attribute height: Expected length, "[object Object]".
I @ jlottie.js:1267
jlottie.js:1269 Error: <rect> attribute x: Expected length, "NaN".
I @ jlottie.js:1269
jlottie.js:1270 Error: <rect> attribute y: Expected length, "NaN".
I @ jlottie.js:1270
jlottie.js:1117 Uncaught TypeError: Cannot set properties of undefined (setting '0')
    at S (jlottie.js:1117)
    at j (jlottie.js:1199)
    at K (jlottie.js:2640)
    at K (jlottie.js:2591)
    at K (jlottie.js:2591)
    at U (jlottie.js:2863)
    at XMLHttpRequest.u.onreadystatechange (jlottie.js:2959)

[shaafiee]

We will put this feature request on a faster track. The importance of it is certainly acknowledged.