tests, fix for default_should_widen

src/axes.jl

@@ -568,7 +568,8 @@ function default_should_widen(axis::Axis)
         return axis[:widen]
     end
     # automatic behavior: widen if limits aren't specified and series type is appropriate
-    (is_2tuple(axis[:lims]) || axis[:lims] == :round) && return false
+    lims = parse_limits(axis[:lims])
+    (lims isa Tuple || lims == :round) && return false
     for sp in axis.sps
         for series in series_list(sp)
             if series.plotattributes[:seriestype] in _widen_seriestypes
@@ -587,21 +588,15 @@ function round_limits(amin, amax, scale)
     amin, amax
 end
 
-parse_limits(lims::Tuple{<:Real, <:Real}, letter) = lims
-parse_limits(lims::Symbol, letter) = lims
-parse_limits(lims::AVec, letter) = if length(lims) == 2 && all(x isa Real for x in lims)
-    Tuple(lims)
-else
-    limits_err(lims, letter)
-end
-parse_limits(lims, letter) = limits_err(lims, letter)
+parse_limits(lims::Tuple{<:Real,<:Real}) = lims
+parse_limits(lims::Symbol) = lims
+parse_limits(lims::AVec) = length(lims) == 2 && all(x isa Real for x in lims) ? Tuple(lims) : nothing
+parse_limits(lims) = nothing 
 
-function limits_err(lims, letter)
-    @warn """Invalid limits for $letter axis. Limits should be a symbol, or a two-element tuple or vector of numbers.
-             $(letter)lims = $lims
-             """
-    nothing
-end
+warn_invalid_limits(lims, letter) = @warn """
+        Invalid limits for $letter axis. Limits should be a symbol, or a two-element tuple or vector of numbers.
+        $(letter)lims = $lims
+        """
 
 # using the axis extrema and limit overrides, return the min/max value for this axis
 function axis_limits(
@@ -613,7 +608,8 @@ function axis_limits(
     axis = sp[get_attr_symbol(letter, :axis)]
     ex = axis[:extrema]
     amin, amax = ex.emin, ex.emax
-    lims = parse_limits(axis[:lims], letter)
+    lims = parse_limits(axis[:lims])
+    lims === nothing && warn_invalid_limits(axis[:lims], letter)
     has_user_lims = lims isa Tuple
     if has_user_lims
         lmin, lmax = lims

src/utils.jl

@@ -370,10 +370,6 @@ ticksType(ticks::Tuple{T,S}) where {T<:Union{AVec,Tuple},S<:Union{AVec,Tuple}} =
     :ticks_and_labels
 ticksType(ticks) = :invalid
 
-limsType(lims::Tuple{T,S}) where {T<:Real,S<:Real} = :limits
-limsType(lims::Symbol) = lims == :auto ? :auto : :invalid
-limsType(lims) = :invalid
-
 # recursively merge kw-dicts, e.g. for merging extra_kwargs / extra_plot_kwargs in plotly)
 recursive_merge(x::AbstractDict...) = merge(recursive_merge, x...)
 # if values are not AbstractDicts, take the last definition (as does merge)

test/test_axes.jl

@@ -42,11 +42,21 @@ end
     pl = plot([1.05, 2.0, 2.95], ylims = :round)
     @test Plots.ylims(pl) == (1, 3)
 
-    pl = plot(1:3, xlims = (1, 5))
-    @test Plots.xlims(pl) == (1, 5)
+    for x in (1:3, -10:10), xlims in ((1, 5), [1, 5])
+        pl = plot(x; xlims)
+        @test Plots.xlims(pl) == (1, 5)
+        pl = plot(x; xlims, widen = true)
+        @test Plots.xlims(pl) == Plots.widen(1, 5)
+    end
 
-    pl = plot(1:3, xlims = (1, 5), widen = true)
-    @test Plots.xlims(pl) == Plots.widen(1, 5)
+    pl = plot(1:5, lims = :symmetric, widen = false)
+    @test Plots.xlims(pl) == Plots.ylims(pl) == (-5, 5)
+
+    for xlims in (0, 0.0, false, true, plot())
+        pl = plot(1:5; xlims)
+        @test Plots.xlims(pl) == Plots.widen(1, 5)
+        @test_logs (:warn, r"Invalid limits for x axis") match_mode=:any display(pl)
+    end
 end
 
 @testset "3D Axis" begin