From 89c68d98b07ac6e14fc6af8edd8e8960393c97bb Mon Sep 17 00:00:00 2001
From: t-bltg <tf.bltg@gmail.com>
Date: Mon, 26 Sep 2022 22:03:50 +0200
Subject: [PATCH] fix single `:auto` in `xlims` or `ylims` (#4378)

---
 src/axes.jl       | 15 +++++++++------
 test/test_axes.jl | 20 ++++++++++++++++++++
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/src/axes.jl b/src/axes.jl
index db13eb6d2..1118bb9ef 100644
--- a/src/axes.jl
+++ b/src/axes.jl
@@ -585,10 +585,11 @@ function round_limits(amin, amax, scale)
     amin, amax
 end
 
-process_limits(lims::Tuple{<:Real,<:Real}) = lims
+process_limits(lims::Tuple{<:Union{Symbol,Real},<:Union{Symbol,Real}}) = lims
 process_limits(lims::Symbol) = lims
 process_limits(lims::AVec) =
-    length(lims) == 2 && all(x isa Real for x in lims) ? Tuple(lims) : nothing
+    length(lims) == 2 && all(map(x -> x isa Union{Symbol,Real}, lims)) ? Tuple(lims) :
+    nothing
 process_limits(lims) = nothing
 
 warn_invalid_limits(lims, letter) = @warn """
@@ -611,13 +612,15 @@ function axis_limits(
     has_user_lims = lims isa Tuple
     if has_user_lims
         lmin, lmax = lims
-        if lmin === :auto
-        elseif isfinite(lmin)
+        if lmin isa Number && isfinite(lmin)
             amin = lmin
+        else
+            lmin === :auto || @warn "Invalid min limit" lmin
         end
-        if lmax === :auto
-        elseif isfinite(lmax)
+        if lmax isa Number && isfinite(lmax)
             amax = lmax
+        else
+            lmax === :auto || @warn "Invalid max $(letter)limit" lmax
         end
     end
     if lims === :symmetric
diff --git a/test/test_axes.jl b/test/test_axes.jl
index 2f416a80b..58df49686 100644
--- a/test/test_axes.jl
+++ b/test/test_axes.jl
@@ -72,6 +72,26 @@ end
             )
         @test plims == Plots.widen(1, 5)
     end
+
+    @testset "JuliaPlots/Plots.jl/issues/4379" begin
+        for ylims in ((-5, :auto), [-5, :auto])
+            pl = plot([-2, 3], ylims = ylims, widen = false)
+            @test Plots.ylims(pl) == (-5.0, 3.0)
+        end
+        for ylims in ((:auto, 4), [:auto, 4])
+            pl = plot([-2, 3], ylims = ylims, widen = false)
+            @test Plots.ylims(pl) == (-2.0, 4.0)
+        end
+
+        for xlims in ((-3, :auto), [-3, :auto])
+            pl = plot([-2, 3], [-1, 1], xlims = xlims, widen = false)
+            @test Plots.xlims(pl) == (-3.0, 3.0)
+        end
+        for xlims in ((:auto, 4), [:auto, 4])
+            pl = plot([-2, 3], [-1, 1], xlims = xlims, widen = false)
+            @test Plots.xlims(pl) == (-2.0, 4.0)
+        end
+    end
 end
 
 @testset "3D Axis" begin