calling JSON.json on a PlotlyLight Plot causes stackoverflow

[disberd]

I stumbled upon this issues because of failing tests in PlotlyKaleido in the last days.

With version 0.8 of PlotlyLight, one can't seem to call JSON.json on the object without causing an error:

julia> using PlotlyLight, JSON

julia> p = Plot(Config(x = rand(10)));

julia> json(p)
ERROR: StackOverflowError:
Stacktrace:
  [1] Array
    @ .\boot.jl:477 [inlined]
  [2] Array
    @ .\boot.jl:486 [inlined]
  [3] Array
    @ .\boot.jl:494 [inlined]
  [4] _collect_indices
    @ .\array.jl:777 [inlined]
  [5] collect
    @ .\array.jl:761 [inlined]
  [6] JSON.Writer.CompositeTypeWrapper(x::Plot, syms::Vector{Any}) (repeats 74610 times)
    @ JSON.Writer C:\Users\Alberto.Mengali\.julia\packages\JSON\93Ea8\src\Writer.jl:22
  [7] JSON.Writer.CompositeTypeWrapper(x::Plot)
    @ JSON.Writer C:\Users\Alberto.Mengali\.julia\packages\JSON\93Ea8\src\Writer.jl:23
  [8] lower
    @ C:\Users\Alberto.Mengali\.julia\packages\JSON\93Ea8\src\Writer.jl:45 [inlined]
  [9] show_json
    @ C:\Users\Alberto.Mengali\.julia\packages\JSON\93Ea8\src\Writer.jl:348 [inlined]
 [10] #show_json#9
    @ C:\Users\Alberto.Mengali\.julia\packages\JSON\93Ea8\src\Writer.jl:359 [inlined]
 [11] show_json
    @ C:\Users\Alberto.Mengali\.julia\packages\JSON\93Ea8\src\Writer.jl:357 [inlined]
 [12] print(io::IOBuffer, obj::Plot)
    @ JSON.Writer C:\Users\Alberto.Mengali\.julia\packages\JSON\93Ea8\src\Writer.jl:383
 [13] sprint(f::Function, args::Plot; context::Nothing, sizehint::Int64)
    @ Base .\strings\io.jl:114
 [14] sprint
    @ .\strings\io.jl:107 [inlined]
 [15] json(a::Plot)
    @ JSON.Writer C:\Users\Alberto.Mengali\.julia\packages\JSON\93Ea8\src\Writer.jl:399

This does not happen with version 0.7 of PlotlyLight

[joshday]

Looks like this boiled down to a mistake in Base.propertynames(::Plot). Fixed on master. New release out soon.