add json writer for Date and DateTime

Author: joshday

Project.toml

@@ -6,6 +6,7 @@ version = "0.11.0"
 [deps]
 Artifacts = "56f22d72-fd6d-98f1-02f0-08ddc0907c33"
 Cobweb = "ec354790-cf28-43e8-bb59-b484409b7bad"
+Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
 Downloads = "f43a241f-c20a-4ad4-852c-f6b1247861c6"
 EasyConfig = "acab07b0-f158-46d4-8913-50acef6d41fe"
 JSON3 = "0f8b85d8-7281-11e9-16c2-39a750bddbf1"
@@ -15,6 +16,7 @@ Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 Aqua = "0.8"
 Artifacts = "1.3"
 Cobweb = "0.6, 0.7"
+Dates = "1.11.0"
 Downloads = "1.6"
 EasyConfig = "0.1"
 JSON3 = "1.14"

src/PlotlyLight.jl

@@ -3,6 +3,7 @@ module PlotlyLight
 using Artifacts: @artifact_str
 using Downloads: download
 using Random: randstring
+using Dates
 
 using JSON3: JSON3
 using EasyConfig: Config

src/json.jl

@@ -22,6 +22,8 @@ json(io::IO, args...) = foreach(x -> json(io, x), args)
 
 # Strings
 json(io::IO, x::Union{AbstractChar, AbstractString, Symbol}) = print(io, '"', x, '"')
+json(io::IO, x::DateTime) = json(io, Dates.format(x, "YYYY-mm-dd HH:MM:SS"))
+json(io::IO, x::Date) = json(io, Dates.format(x, "YYYY-mm-dd"))
 
 # Numbers
 json(io::IO, x::Real) = isfinite(x) ? print(io, x) : print(io, "null")

test/runtests.jl

@@ -25,6 +25,7 @@ html(x) = repr("text/html", x)
     @test json(NaN) == "null"
     @test json(Inf) == "null"
     @test json(-Inf) == "null"
+    @test json(DateTime(2021,1,1)) == "\"2021-01-01 00:00:00\""
 end
 
 #-----------------------------------------------------------------------------# Plot methods