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I tried to search this and figure out exactly how it work but I'm having trouble finding an explanation.
If i have a variable data of type interface{} (data interface{})
What would eventData := data.(map[string]interface{}) be doing? I know interface can represent a number of things, but what is a high level overview of what his happening here?
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It is a type assertion:
A type assertion provides access to an interface value's underlying concrete value.
t := i.(T)
https://tour.golang.org/methods/15
If the asserion does not hold it will trigger a panic. To test if the value is of specific type T you can use this:
t, ok := i.(T)
Ok is a boolean that is true if the assertion holds and false otherwise.