Fix error in type cast.

[chingjun]

Casting to List<String> is an error when the original list is List<dynamic>.

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[christopherfujino]

I'm a little confused as to this fix:

Casting to List is an error when the original list is List.

even after this change, the object could still be a list. It doesn't seem like calling list.cast<T>() where list is already a List<T> does not seem to be an error. Also, the test you added still passes without this fix.

[chingjun]

Github removed everything between <> in my original comment, I meant to say "casting to List<String> is an error when the original list is List<dynamic>."

Updated the original description.

And I missed a step in the test, I've updated the test to convert it to JSON string, and parse the JSON into a Map<String, Object>, and then run DebuggingOptions.fromJson.

The object returned from json.decode is a List<dynamic>, and it is an error to cast that to List<String> directly. It should be casted by using (list as List<dynamic>).cast<String>()

PTAL, thanks

[christopherfujino]

Ahh, ok, that makes sense now :)

[christopherfujino]

LGTM

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