fix vector of shapes (#3517)

src/components.jl

@@ -43,7 +43,7 @@ function coords(shape::Shape)
 end
 
 #coords(shapes::AVec{Shape}) = unzip(map(coords, shapes))
-function coords(shapes::AVec{Shape})
+function coords(shapes::AVec{<:Shape})
     c = map(coords, shapes)
     x = [q[1] for q in c]
     y = [q[2] for q in c]

src/recipes.jl

@@ -1428,9 +1428,9 @@ end
     coords(shape)
 end
 
-@recipe function f(shapes::AVec{Shape})
+@recipe function f(shapes::AVec{<:Shape})
     seriestype --> :shape
-    # For backwards compatibility, column vectors of segmenting attributes are 
+    # For backwards compatibility, column vectors of segmenting attributes are
     # interpreted as having one element per shape
     for attr in union(_segmenting_array_attributes, _segmenting_vector_attributes)
         v = get(plotattributes, attr, nothing)
@@ -1443,7 +1443,7 @@ end
     coords(shapes)
 end
 
-@recipe function f(shapes::AMat{Shape})
+@recipe function f(shapes::AMat{<:Shape})
     seriestype --> :shape
     for j in axes(shapes, 2)
         @series coords(vec(shapes[:, j]))

test/test_components.jl

@@ -4,6 +4,7 @@ using Plots, Test
     @testset "Type" begin
         square = Shape([(0,0.0),(1,0.0),(1,1.0),(0,1.0)])
         @test isa(square, Shape{Int64, Float64})
+        @test coords(square) isa Tuple{Vector{S}, Vector{T}} where {T,S}
     end
 
     @testset "Copy" begin
@@ -47,6 +48,16 @@ using Plots, Test
         @test square2.x ≈ coords[1,:]
         @test square2.y ≈ coords[2,:]
     end
+
+    @testset "Plot" begin
+        ang = range(0, 2π, length = 60)
+        ellipse(x, y, w, h) = Shape(w*sin.(ang).+x, h*cos.(ang).+y)
+        myshapes = [ellipse(x,rand(),rand(),rand()) for x = 1:4]
+        @test coords(myshapes) isa Tuple{Vector{Vector{S}}, Vector{Vector{T}}} where {T,S}
+        local p
+        @test_nowarn p = plot(myshapes)
+        @test p[1][1][:seriestype] == :shape
+    end
 end
 
 @testset "Brush" begin