diff --git a/PlotsBase/ext/GRExt.jl b/PlotsBase/ext/GRExt.jl
index f180c6fcf..5bc1e7f67 100644
--- a/PlotsBase/ext/GRExt.jl
+++ b/PlotsBase/ext/GRExt.jl
@@ -1,6 +1,5 @@
 module GRExt
 
-
 import PlotsBase: PlotsBase, _cycle
 import RecipesPipeline
 import NaNMath
@@ -221,7 +220,6 @@ end
 
 PlotsBase.is_marker_supported(::GRBackend, shape::Shape) = true
 
-
 # https://github.com/jheinen/GR.jl - significant contributions by @jheinen
 
 const gr_projections = (auto = 1, ortho = 1, orthographic = 1, persp = 2, perspective = 2)
@@ -1984,7 +1982,8 @@ function gr_add_series(sp, series)
         GR.gr3.clear()
     elseif st === :heatmap
         # `z` is already transposed, so we need to reverse before passing its size.
-        x, y = PlotsBase.heatmap_edges(x, xscale, y, yscale, reverse(size(z)), ispolar(series))
+        x, y =
+            PlotsBase.heatmap_edges(x, xscale, y, yscale, reverse(size(z)), ispolar(series))
         gr_draw_heatmap(series, x, y, z, clims)
     elseif st === :image
         gr_draw_image(series, x, y, z, clims)
@@ -2214,7 +2213,9 @@ function gr_draw_heatmap(series, x, y, z, clims)
     GR.setspace(clims..., 0, 90)
     w, h = length(x) - 1, length(y) - 1
     sp = series[:subplot]
-    if !ispolar(series) && PlotsBase.is_uniformly_spaced(x) && PlotsBase.is_uniformly_spaced(y)
+    if !ispolar(series) &&
+       PlotsBase.is_uniformly_spaced(x) &&
+       PlotsBase.is_uniformly_spaced(y)
         # For uniformly spaced data use GR.drawimage, which can be
         # much faster than GR.nonuniformcellarray, especially for
         # pdf output, and also supports alpha values.
diff --git a/PlotsBase/ext/HDF5Ext.jl b/PlotsBase/ext/HDF5Ext.jl
index 90904e6f4..1aeaf7783 100644
--- a/PlotsBase/ext/HDF5Ext.jl
+++ b/PlotsBase/ext/HDF5Ext.jl
@@ -8,8 +8,10 @@ import PlotUtils.Colors: Colorant
 import RecipesPipeline
 
 import RecipesPipeline.datetimeformatter
-import PlotUtils.ColorPalette, PlotUtils.CategoricalColorGradient, PlotUtils.ContinuousColorGradient
-import PlotsBase: PlotsBase, Surface, Arrow, GridLayout, RootLayout, Font, PlotText, SeriesAnnotations
+import PlotUtils.ColorPalette,
+    PlotUtils.CategoricalColorGradient, PlotUtils.ContinuousColorGradient
+import PlotsBase:
+    PlotsBase, Surface, Arrow, GridLayout, RootLayout, Font, PlotText, SeriesAnnotations
 import PlotsBase: BoundingBox, Length, Plot, DefaultsDict, plot, plot!
 
 using PlotsBase.PlotsSeries
@@ -149,7 +151,6 @@ end
 # PlotsBase.supported_scales(::HDF5Backend) -> ::Vector{Symbol}
 # -----------------------------------------------------------------------------
 
-
 # Additional constants
 # Dict has problems using "Types" as keys.  Initialize in "_initialize_backend":
 const HDF5PLOT_MAP_STR2TELEM = Dict{String,Type}()
@@ -620,5 +621,4 @@ end
 
 hdf5plot_write(path::AbstractString) = hdf5plot_write(current(), path)
 
-
 end # module
diff --git a/PlotsBase/ext/PGFPlotsXExt.jl b/PlotsBase/ext/PGFPlotsXExt.jl
index 8e95bac90..e72abe26f 100644
--- a/PlotsBase/ext/PGFPlotsXExt.jl
+++ b/PlotsBase/ext/PGFPlotsXExt.jl
@@ -321,7 +321,8 @@ curly(obj) = "{$(string(obj))}"
 latex_formatter(formatter::Symbol) = formatter in (:plain, :latex) ? formatter : :latex
 latex_formatter(formatter::Function) = formatter
 
-PlotsBase.labelfunc(scale::Symbol, backend::PGFPlotsXBackend) = PlotsBase.labelfunc_tex(scale)
+PlotsBase.labelfunc(scale::Symbol, backend::PGFPlotsXBackend) =
+    PlotsBase.labelfunc_tex(scale)
 
 pgfx_halign(k) = (left = "left", hcenter = "center", center = "center", right = "right")[k]
 
@@ -1601,18 +1602,27 @@ end
 
 PlotsBase._create_backend_figure(plt::Plot{PGFPlotsXBackend}) = plt.o = PGFPlotsXPlot()
 
-PlotsBase._series_added(plt::Plot{PGFPlotsXBackend}, series::Series) = plt.o.is_created = false
+PlotsBase._series_added(plt::Plot{PGFPlotsXBackend}, series::Series) =
+    plt.o.is_created = false
 
 PlotsBase._update_plot_object(plt::Plot{PGFPlotsXBackend}) = plt.o(plt)
 
 for mime in ("application/pdf", "image/svg+xml", "image/png")
-    @eval function PlotsBase._show(io::IO, mime::MIME{Symbol($mime)}, plt::Plot{PGFPlotsXBackend})
+    @eval function PlotsBase._show(
+        io::IO,
+        mime::MIME{Symbol($mime)},
+        plt::Plot{PGFPlotsXBackend},
+    )
         plt.o.was_shown = true
         show(io, mime, plt.o.the_plot)
     end
 end
 
-function PlotsBase._show(io::IO, mime::MIME{Symbol("application/x-tex")}, plt::Plot{PGFPlotsXBackend})
+function PlotsBase._show(
+    io::IO,
+    mime::MIME{Symbol("application/x-tex")},
+    plt::Plot{PGFPlotsXBackend},
+)
     plt.o.was_shown = true
     PGFPlotsX.print_tex(
         io,
diff --git a/PlotsBase/ext/PlotlyJSExt.jl b/PlotsBase/ext/PlotlyJSExt.jl
index e4050a697..27f06a4c1 100644
--- a/PlotsBase/ext/PlotlyJSExt.jl
+++ b/PlotsBase/ext/PlotlyJSExt.jl
@@ -1,6 +1,5 @@
 module PlotlyJSExt
 
-
 import PlotsBase: PlotsBase, Plot, isijulia
 using PlotsBase.PlotsPlots
 using PlotsBase.Commons
@@ -90,8 +89,11 @@ for (mime, fmt) in (
 end
 
 # Use the Plotly implementation for json and html:
-PlotsBase._show(io::IO, mime::MIME"application/vnd.plotly.v1+json", plt::Plot{PlotlyJSBackend}) =
-    plotly_show_js(io, plt)
+PlotsBase._show(
+    io::IO,
+    mime::MIME"application/vnd.plotly.v1+json",
+    plt::Plot{PlotlyJSBackend},
+) = plotly_show_js(io, plt)
 
 PlotsBase.html_head(plt::Plot{PlotlyJSBackend}) = PlotsBase.Plotly.plotly_html_head(plt)
 PlotsBase.html_body(plt::Plot{PlotlyJSBackend}) = PlotsBase.Plotly.plotly_html_body(plt)
@@ -101,8 +103,7 @@ PlotsBase._show(io::IO, ::MIME"text/html", plt::Plot{PlotlyJSBackend}) =
 
 PlotsBase._display(plt::Plot{PlotlyJSBackend}) = display(plotlyjs_syncplot(plt))
 
-WebIO.render(plt::Plot{PlotlyJSBackend}) =
-    WebIO.render(plotlyjs_syncplot(plt))
+WebIO.render(plt::Plot{PlotlyJSBackend}) = WebIO.render(plotlyjs_syncplot(plt))
 
 PlotsBase.closeall(::PlotlyJSBackend) =
     if !PlotsBase.isplotnull() && isa(PlotsBase.current().o, PlotlyJS.SyncPlot)
diff --git a/PlotsBase/ext/PythonPlotExt.jl b/PlotsBase/ext/PythonPlotExt.jl
index 34073353d..5b37e0bd6 100644
--- a/PlotsBase/ext/PythonPlotExt.jl
+++ b/PlotsBase/ext/PythonPlotExt.jl
@@ -1002,7 +1002,8 @@ function _py_compute_axis_minval(sp::Subplot, axis::Axis)
 end
 
 function _py_set_scale(ax, sp::Subplot, scale::Symbol, letter::Symbol)
-    scale ∈ PlotsBase.supported_scales() || return @warn "Unhandled scale value in PythonPlot: $scale"
+    scale ∈ PlotsBase.supported_scales() ||
+        return @warn "Unhandled scale value in PythonPlot: $scale"
     scl, kw = if scale === :identity
         "linear", KW()
     else
@@ -1451,7 +1452,8 @@ function PlotsBase._before_layout_calcs(plt::Plot{PythonPlotBackend})
 end
 
 expand_padding!(padding, bb, plotbb) =
-    if PlotsBase.ispositive(PlotsBase.width(bb)) && PlotsBase.ispositive(PlotsBase.height(bb))
+    if PlotsBase.ispositive(PlotsBase.width(bb)) &&
+       PlotsBase.ispositive(PlotsBase.height(bb))
         padding[1] = max(padding[1], PlotsBase.left(plotbb) - PlotsBase.left(bb))
         padding[2] = max(padding[2], PlotsBase.top(plotbb) - PlotsBase.top(bb))
         padding[3] = max(padding[3], PlotsBase.right(bb) - PlotsBase.right(plotbb))
@@ -1541,7 +1543,13 @@ function _py_legend_pos(pos::Tuple{<:Real,Symbol})
     s, c = sincosd(pos[1]) .* (pos[2] === :outer ? -1 : 1)
     yanchors = "lower", "center", "upper"
     xanchors = "left", "center", "right"
-    join([yanchors[PlotsBase.legend_anchor_index(s)], xanchors[PlotsBase.legend_anchor_index(c)]], ' ')
+    join(
+        [
+            yanchors[PlotsBase.legend_anchor_index(s)],
+            xanchors[PlotsBase.legend_anchor_index(c)],
+        ],
+        ' ',
+    )
 end
 
 # legend_pos_from_angle(theta, xmin, xcenter, xmax, ymin, ycenter, ymax)
@@ -1706,8 +1714,11 @@ function PlotsBase._update_plot_object(plt::Plot{PythonPlotBackend})
                 PlotsBase.width(bb),  # width
                 PlotsBase.height(sp.bbox) - 2pad,  # height
             )
-            get(sp[:extra_kwargs], "3d_colorbar_axis", PlotsBase.bbox_to_pcts(cb_bbox, figw, figh)) |>
-            sp.attr[:cbar_ax].set_position
+            get(
+                sp[:extra_kwargs],
+                "3d_colorbar_axis",
+                PlotsBase.bbox_to_pcts(cb_bbox, figw, figh),
+            ) |> sp.attr[:cbar_ax].set_position
         end
     end
     PythonPlot.draw()
@@ -1727,7 +1738,11 @@ for (mime, fmt) in (
     "image/svg+xml"          => "svg",
     "application/x-tex"      => "pgf",
 )
-    @eval function PlotsBase._show(io::IO, ::MIME{Symbol($mime)}, plt::Plot{PythonPlotBackend})
+    @eval function PlotsBase._show(
+        io::IO,
+        ::MIME{Symbol($mime)},
+        plt::Plot{PythonPlotBackend},
+    )
         fig = plt.o
         fig.canvas.print_figure(
             io,
diff --git a/PlotsBase/ext/UnicodePlotsExt.jl b/PlotsBase/ext/UnicodePlotsExt.jl
index 0070f3ab4..b517e2176 100644
--- a/PlotsBase/ext/UnicodePlotsExt.jl
+++ b/PlotsBase/ext/UnicodePlotsExt.jl
@@ -412,7 +412,11 @@ end
 
 # ------------------------------------------------------------------------------------------
 
-function PlotsBase._show(io::IO, ::MIME"image/png", plt::PlotsBase.Plot{UnicodePlotsBackend})
+function PlotsBase._show(
+    io::IO,
+    ::MIME"image/png",
+    plt::PlotsBase.Plot{UnicodePlotsBackend},
+)
     applicable(UnicodePlots.save_image, io) ||
         "PlotsBase(UnicodePlots): saving to `.png` requires `import FreeType, FileIO`" |>
         ArgumentError |>
@@ -458,10 +462,15 @@ function PlotsBase._show(io::IO, ::MIME"image/png", plt::PlotsBase.Plot{UnicodeP
 end
 
 Base.show(plt::PlotsBase.Plot{UnicodePlotsBackend}) = show(stdout, plt)
-Base.show(io::IO, plt::PlotsBase.Plot{UnicodePlotsBackend}) = PlotsBase._show(io, MIME("text/plain"), plt)
+Base.show(io::IO, plt::PlotsBase.Plot{UnicodePlotsBackend}) =
+    PlotsBase._show(io, MIME("text/plain"), plt)
 
 # NOTE: _show(...) must be kept for Base.showable (src/output.jl)
-function PlotsBase._show(io::IO, ::MIME"text/plain", plt::PlotsBase.Plot{UnicodePlotsBackend})
+function PlotsBase._show(
+    io::IO,
+    ::MIME"text/plain",
+    plt::PlotsBase.Plot{UnicodePlotsBackend},
+)
     PlotsBase.prepare_output(plt)
     nr, nc = size(plt.layout)
     if nr == 1 && nc == 1  # fast path
diff --git a/PlotsBase/ext/UnitfulExt.jl b/PlotsBase/ext/UnitfulExt.jl
index 059a1d53a..ede2e5713 100644
--- a/PlotsBase/ext/UnitfulExt.jl
+++ b/PlotsBase/ext/UnitfulExt.jl
@@ -3,7 +3,20 @@
 
 module UnitfulExt
 
-import Unitful: Unitful, Quantity, unit, ustrip, dimension, Units, NoUnits, LogScaled, logunit, MixedUnits, Level, Gain, uconvert
+import Unitful:
+    Unitful,
+    Quantity,
+    unit,
+    ustrip,
+    dimension,
+    Units,
+    NoUnits,
+    LogScaled,
+    logunit,
+    MixedUnits,
+    Level,
+    Gain,
+    uconvert
 import PlotsBase: PlotsBase, @recipe, PlotText, Subplot, AVec, AMat, Axis
 import RecipesBase
 import LaTeXStrings: LaTeXString
diff --git a/PlotsBase/src/Commons/Commons.jl b/PlotsBase/src/Commons/Commons.jl
index 83858ce55..5d995153d 100644
--- a/PlotsBase/src/Commons/Commons.jl
+++ b/PlotsBase/src/Commons/Commons.jl
@@ -111,7 +111,8 @@ all_styles(arg) =
     true_or_all_true(a -> get(Commons._styleAliases, a, a) in Commons._all_styles, arg)
 all_shapes(arg) = (true_or_all_true(
     a ->
-        get(Commons._marker_aliases, a, a) in Commons._all_markers || a isa PlotsBase.Shape,
+        get(Commons._marker_aliases, a, a) in Commons._all_markers ||
+            a isa PlotsBase.Shape,
     arg,
 ))
 all_alphas(arg) = true_or_all_true(
diff --git a/PlotsBase/src/PlotsBase.jl b/PlotsBase/src/PlotsBase.jl
index fcba5a9e8..c78fef6f6 100644
--- a/PlotsBase/src/PlotsBase.jl
+++ b/PlotsBase/src/PlotsBase.jl
@@ -201,4 +201,4 @@ using .Plotly
 include("init.jl")
 include("users.jl")
 
-end
\ No newline at end of file
+end
diff --git a/PlotsBase/src/Series.jl b/PlotsBase/src/Series.jl
index 251b5ff1b..411e82549 100644
--- a/PlotsBase/src/Series.jl
+++ b/PlotsBase/src/Series.jl
@@ -225,7 +225,8 @@ struct NaNSegmentsIterator
 end
 
 function Base.iterate(itr::NaNSegmentsIterator, nextidx::Int = itr.n1)
-    (i = findfirst(!PlotsBase.Commons.anynan(itr.args), nextidx:(itr.n2))) === nothing && return
+    (i = findfirst(!PlotsBase.Commons.anynan(itr.args), nextidx:(itr.n2))) === nothing &&
+        return
     nextval = nextidx + i - 1
 
     j = findfirst(PlotsBase.Commons.anynan(itr.args), nextval:(itr.n2))
diff --git a/PlotsBase/src/backends/plotly.jl b/PlotsBase/src/backends/plotly.jl
index ce3ee8096..9a97182cf 100644
--- a/PlotsBase/src/backends/plotly.jl
+++ b/PlotsBase/src/backends/plotly.jl
@@ -519,7 +519,8 @@ function plotly_layout(plt::Plot)
         plotattributes_out[:hovermode] = "none"
     end
 
-    plotattributes_out = PlotsBase.recursive_merge(plotattributes_out, plt.attr[:extra_plot_kwargs])
+    plotattributes_out =
+        PlotsBase.recursive_merge(plotattributes_out, plt.attr[:extra_plot_kwargs])
 end
 
 function plotly_add_legend!(plotattributes_out::KW, sp::Subplot)
@@ -1317,7 +1318,8 @@ Base.showable(::MIME"application/prs.juno.plotpane+html", plt::Plot{PlotlyBacken
 PlotsBase._show(io::IO, ::MIME"application/vnd.plotly.v1+json", plot::Plot{PlotlyBackend}) =
     plotly_show_js(io, plot)
 
-PlotsBase._show(io::IO, ::MIME"text/html", plt::Plot{PlotlyBackend}) = write(io, PlotsBase.embeddable_html(plt))
+PlotsBase._show(io::IO, ::MIME"text/html", plt::Plot{PlotlyBackend}) =
+    write(io, PlotsBase.embeddable_html(plt))
 
 PlotsBase._display(plt::Plot{PlotlyBackend}) = standalone_html_window(plt)
 
diff --git a/PlotsBase/src/examples.jl b/PlotsBase/src/examples.jl
index 77201932f..96c40facc 100644
--- a/PlotsBase/src/examples.jl
+++ b/PlotsBase/src/examples.jl
@@ -179,8 +179,10 @@ const _examples = PlotExample[
     PlotExample( # 13
         "Marker types",
         quote
-            markers =
-                filter(m -> m in PlotsBase.supported_markers(), PlotsBase.Commons._shape_keys)
+            markers = filter(
+                m -> m in PlotsBase.supported_markers(),
+                PlotsBase.Commons._shape_keys,
+            )
             markers = permutedims(markers)
             n = length(markers)
             x = range(0, stop = 10, length = n + 2)[2:(end - 1)]
@@ -295,7 +297,11 @@ const _examples = PlotExample[
         """,
         quote
             y = rand(10)
-            plot(y, annotations = (3, y[3], PlotsBase.text("this is #3", :left)), leg = false)
+            plot(
+                y,
+                annotations = (3, y[3], PlotsBase.text("this is #3", :left)),
+                leg = false,
+            )
             # single vector of annotation tuples
             annotate!([
                 (5, y[5], ("this is #5", 16, :red, :center)),
@@ -1328,7 +1334,7 @@ replace_module(ex) = ex
 function replace_module(ex::Expr)
     if Meta.isexpr(ex, :import) || Meta.isexpr(ex, :using)
         expr = Expr(ex.head)
-        for arg ∈ ex.args
+        for arg in ex.args
             mod = last(arg.args)
             new_arg = if Meta.isexpr(arg, :.)
                 mod ≡ :PlotsBase ? arg : Expr(:., :PlotsBase, mod)
diff --git a/PlotsBase/src/utils.jl b/PlotsBase/src/utils.jl
index f4e7fe725..ef38e1baa 100644
--- a/PlotsBase/src/utils.jl
+++ b/PlotsBase/src/utils.jl
@@ -1,6 +1,6 @@
 
 # ---------------------------------------------------------------
-bool_env(x, default::String="0")::Bool = tryparse(Bool, get(ENV, x, default))
+bool_env(x, default::String = "0")::Bool = tryparse(Bool, get(ENV, x, default))
 
 treats_y_as_x(seriestype) =
     seriestype in (:vline, :vspan, :histogram, :barhist, :stephist, :scatterhist)
diff --git a/PlotsBase/test/runtests.jl b/PlotsBase/test/runtests.jl
index 08ecdce51..2d8048ad1 100644
--- a/PlotsBase/test/runtests.jl
+++ b/PlotsBase/test/runtests.jl
@@ -1,4 +1,14 @@
-const TEST_PACKAGES = strip.(split(get(ENV, "PLOTSBASE_TEST_PACKAGES", "GR,UnicodePlots,PythonPlot,PGFPlotsX,PlotlyJS,Gaston"), ","))
+const TEST_PACKAGES =
+    strip.(
+        split(
+            get(
+                ENV,
+                "PLOTSBASE_TEST_PACKAGES",
+                "GR,UnicodePlots,PythonPlot,PGFPlotsX,PlotlyJS,Gaston",
+            ),
+            ",",
+        )
+    )
 const TEST_BACKENDS = Symbol.(lowercase.(TEST_PACKAGES))
 
 using PlotsBase
diff --git a/PlotsBase/test/test_axes.jl b/PlotsBase/test/test_axes.jl
index f22f187f1..abda149df 100644
--- a/PlotsBase/test/test_axes.jl
+++ b/PlotsBase/test/test_axes.jl
@@ -36,7 +36,8 @@
     @test PlotsBase.get_labels(:auto, 1:3, :ln) == ["e^{1}", "e^{2}", "e^{3}"]
     @test PlotsBase.get_labels(:latex, 1:3, :log10) ==
           ["\$10^{1}\$", "\$10^{2}\$", "\$10^{3}\$"]
-    @test PlotsBase.get_labels(:latex, 1:3, :log2) == ["\$2^{1}\$", "\$2^{2}\$", "\$2^{3}\$"]
+    @test PlotsBase.get_labels(:latex, 1:3, :log2) ==
+          ["\$2^{1}\$", "\$2^{2}\$", "\$2^{3}\$"]
     @test PlotsBase.get_labels(:latex, 1:3, :ln) == ["\$e^{1}\$", "\$e^{2}\$", "\$e^{3}\$"]
 
     @test PlotsBase.get_labels(x -> 1e3x, 1:3, :identity) == ["1000", "2000", "3000"]
diff --git a/PlotsBase/test/test_backends.jl b/PlotsBase/test/test_backends.jl
index 9cc6453f9..b30111944 100644
--- a/PlotsBase/test/test_backends.jl
+++ b/PlotsBase/test/test_backends.jl
@@ -155,7 +155,10 @@ end
 
         pl = plot([Dates.Date(2019, 1, 1), Dates.Date(2019, 2, 1)], [3, 4])
         hline!(pl, [3.1])
-        annotate!(pl, [(Dates.Date(2019, 1, 15), 3.2, PlotsBase.text("Test", :red, :center))])
+        annotate!(
+            pl,
+            [(Dates.Date(2019, 1, 15), 3.2, PlotsBase.text("Test", :red, :center))],
+        )
         @test show(io, pl) isa Nothing
 
         pl = plot([Dates.Date(2019, 1, 1), Dates.Date(2019, 2, 1)], [3, 4])
@@ -222,7 +225,7 @@ is_pkgeval() || @testset "Examples" begin
         )
         @test filesize(fn) > 1_000
     end
-    Sys.islinux() && for be ∈ TEST_BACKENDS
+    Sys.islinux() && for be in TEST_BACKENDS
         skip = vcat(PlotsBase._backend_skips[be], blacklist)
         PlotsBase.test_examples(be; skip, callback, disp = is_ci(), strict = true)  # `ci` display for coverage
         closeall()
diff --git a/PlotsBase/test/test_hdf5plots.jl b/PlotsBase/test/test_hdf5plots.jl
index 01a16acac..c9bf158d0 100644
--- a/PlotsBase/test/test_hdf5plots.jl
+++ b/PlotsBase/test/test_hdf5plots.jl
@@ -5,7 +5,7 @@ using HDF5
     hdf5()
 
     x = 1:10
-    pl = plot(x, x.^2)  # create some plot
+    pl = plot(x, x .^ 2)  # create some plot
     PlotsBase.hdf5plot_write(pl, fname)
 
     # read back file
diff --git a/PlotsBase/test/test_misc.jl b/PlotsBase/test/test_misc.jl
index 859698dd9..6a53aad68 100644
--- a/PlotsBase/test/test_misc.jl
+++ b/PlotsBase/test/test_misc.jl
@@ -110,7 +110,9 @@ end
     @test PlotsBase.legend_anchor_index(+1) == 3
 
     @test PlotsBase.legend_angle(:foo_bar) == (45, :inner)
-    @test PlotsBase.legend_angle(20.0) == PlotsBase.legend_angle((20.0, :inner)) == (20.0, :inner)
+    @test PlotsBase.legend_angle(20.0) ==
+          PlotsBase.legend_angle((20.0, :inner)) ==
+          (20.0, :inner)
     @test PlotsBase.legend_angle((20.0, 10.0)) == (20.0, 10.0)
 end
 
@@ -211,7 +213,10 @@ end
 end
 
 @testset "docstring" begin
-    @test occursin("label", PlotsBase._generate_doclist(PlotsBase.Commons._all_series_attrs))
+    @test occursin(
+        "label",
+        PlotsBase._generate_doclist(PlotsBase.Commons._all_series_attrs),
+    )
 end
 
 @testset "protect" begin
@@ -324,7 +329,8 @@ with(:gr) do
     end
 
     @testset "legends" begin
-        @test plot([0:1 reverse(0:1)]; labels = ["a" "b"], leg = (0.5, 0.5)) isa PlotsBase.Plot
+        @test plot([0:1 reverse(0:1)]; labels = ["a" "b"], leg = (0.5, 0.5)) isa
+              PlotsBase.Plot
         @test plot([0:1 reverse(0:1)]; labels = ["a" "b"], leg = (0.5, :outer)) isa
               PlotsBase.Plot
         @test plot([0:1 reverse(0:1)]; labels = ["a" "b"], leg = (0.5, :inner)) isa
diff --git a/PlotsBase/test/test_pgfplotsx.jl b/PlotsBase/test/test_pgfplotsx.jl
index 2a9079779..81dde6ea1 100644
--- a/PlotsBase/test/test_pgfplotsx.jl
+++ b/PlotsBase/test/test_pgfplotsx.jl
@@ -107,9 +107,12 @@ with(:pgfplotsx) do
     end
 
     @testset "Marker types" begin
-        markers = filter((m -> begin
-            m in PlotsBase.supported_markers()
-        end), PlotsBase.Commons._shape_keys)
+        markers = filter(
+            (m -> begin
+                m in PlotsBase.supported_markers()
+            end),
+            PlotsBase.Commons._shape_keys,
+        )
         markers = reshape(markers, 1, length(markers))
         n = length(markers)
         x = (range(0, stop = 10, length = n + 2))[2:(end - 1)]
diff --git a/PlotsBase/test/test_unitful.jl b/PlotsBase/test/test_unitful.jl
index bb005917b..69f3a2d40 100644
--- a/PlotsBase/test/test_unitful.jl
+++ b/PlotsBase/test/test_unitful.jl
@@ -227,7 +227,8 @@ end
             @test plot(x * m, y * s, z * (m / s), yunit = u"ks") isa PlotsBase.Plot
             @test plot(x * m, y * s, z * (m / s), zlabel = "z") isa PlotsBase.Plot
             @test plot(x * m, y * s, z * (m / s), zlims = (-1, 1)) isa PlotsBase.Plot
-            @test plot(x * m, y * s, z * (m / s), zlims = (-1, 1) .* (m / s)) isa PlotsBase.Plot
+            @test plot(x * m, y * s, z * (m / s), zlims = (-1, 1) .* (m / s)) isa
+                  PlotsBase.Plot
             @test plot(x * m, y * s, z * (m / s), zunit = u"km/hr") isa PlotsBase.Plot
             @test plot(x * m, y * s, z * (m / s), zticks = (1:2) * m / s) isa PlotsBase.Plot
             @test scatter(x * m, y * s, z * (m / s)) isa PlotsBase.Plot
diff --git a/Project.toml b/Project.toml
index c848b10c6..430295e24 100644
--- a/Project.toml
+++ b/Project.toml
@@ -21,8 +21,9 @@ Reexport = "0.2, 1"
 julia = "1.6"
 
 [extras]
+PythonPlot = "274fc56d-3b97-40fa-a1cd-1b4a50311bf9"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 UnicodePlots = "b8865327-cd53-5732-bb35-84acbb429228"
 
 [targets]
-test = ["Test", "UnicodePlots"]
+test = ["PythonPlot", "Test", "UnicodePlots"]
diff --git a/src/Plots.jl b/src/Plots.jl
index 6ff382e73..3d9c6e9f6 100644
--- a/src/Plots.jl
+++ b/src/Plots.jl
@@ -1,116 +1,121 @@
 module Plots
-    using PrecompileTools
-    using Preferences
-    using Reexport
-    using Pkg
-    @reexport using PlotsBase
+using PrecompileTools
+using Preferences
+using Reexport
+using Pkg
+@reexport using PlotsBase
 
-    function __init__()
-        ccall(:jl_generating_output, Cint, ()) == 1 && return
-        load_default_backend()
-    end
+function __init__()
+    ccall(:jl_generating_output, Cint, ()) == 1 && return
+    load_default_backend()
+end
 
-    # from github.com/JuliaPackaging/Preferences.jl/blob/master/README.md:
-    # "Preferences that are accessed during compilation are automatically marked as compile-time preferences"
-    # ==> this must always be done during precompilation, otherwise
-    # the cache will not invalidate when preferences change
-    const PLOTS_DEFAULT_BACKEND = lowercase(load_preference(Plots, "default_backend", "gr"))
+# from github.com/JuliaPackaging/Preferences.jl/blob/master/README.md:
+# "Preferences that are accessed during compilation are automatically marked as compile-time preferences"
+# ==> this must always be done during precompilation, otherwise
+# the cache will not invalidate when preferences change
+const PLOTS_DEFAULT_BACKEND = lowercase(load_preference(Plots, "default_backend", "gr"))
 
-    function load_default_backend()
-        # environment variable preempts the `Preferences` based mechanism
-        PlotsBase.CURRENT_BACKEND.sym =
-          get(ENV, "PLOTS_DEFAULT_BACKEND", PLOTS_DEFAULT_BACKEND) |> lowercase |> Symbol
-        if (pkg_name = PlotsBase.backend_package_name()) ≡ :GR
-            @eval import GR
-        end
-        Base.invokelatest(PlotsBase.backend, PlotsBase.CURRENT_BACKEND.sym)
+function load_default_backend()
+    # environment variable preempts the `Preferences` based mechanism
+    PlotsBase.CURRENT_BACKEND.sym =
+        get(ENV, "PLOTS_DEFAULT_BACKEND", PLOTS_DEFAULT_BACKEND) |> lowercase |> Symbol
+    if (pkg_name = PlotsBase.backend_package_name()) ≡ :GR
+        @eval import GR
     end
+    Base.invokelatest(PlotsBase.backend, PlotsBase.CURRENT_BACKEND.sym)
+end
 
-    function set_default_backend!(
-      backend::Union{Nothing,AbstractString,Symbol} = nothing;
-      force = true,
-      kw...,
-    )
-        if backend ≡ nothing
-            delete_preferences!(Plots, "default_backend"; force, kw...)
-        else
-            # NOTE: `_check_installed` already throws a warning
-            if (value = lowercase(string(backend))) |> PlotsBase._check_installed ≢ nothing
-                set_preferences!(Plots, "default_backend" => value; force, kw...)
-            end
+function set_default_backend!(
+    backend::Union{Nothing,AbstractString,Symbol} = nothing;
+    force = true,
+    kw...,
+)
+    if backend ≡ nothing
+        delete_preferences!(Plots, "default_backend"; force, kw...)
+    else
+        # NOTE: `_check_installed` already throws a warning
+        if (value = lowercase(string(backend))) |> PlotsBase._check_installed ≢ nothing
+            set_preferences!(Plots, "default_backend" => value; force, kw...)
         end
-        nothing
     end
+    nothing
+end
 
-    function diagnostics(io::IO = stdout)
-        origin = if has_preference(Plots, "default_backend")
-            "`Preferences`"
-        elseif haskey(ENV, "PLOTS_DEFAULT_BACKEND")
-            "environment variable"
-        else
-            "fallback"
-        end
-        if (be = backend_name()) ≡ :none
-            @info "no `Plots` backends currently initialized"
-        else
-            be_name = string(PlotsBase.backend_package_name(be))
-            @info "selected `Plots` backend: $be_name, from $origin"
-            Pkg.status(
-                ["Plots", "PlotsBase", "RecipesBase", "RecipesPipeline", be_name];
-                mode = Pkg.PKGMODE_MANIFEST,
-                io,
-            )
-        end
-        nothing
+function diagnostics(io::IO = stdout)
+    origin = if has_preference(Plots, "default_backend")
+        "`Preferences`"
+    elseif haskey(ENV, "PLOTS_DEFAULT_BACKEND")
+        "environment variable"
+    else
+        "fallback"
+    end
+    if (be = backend_name()) ≡ :none
+        @info "no `Plots` backends currently initialized"
+    else
+        be_name = string(PlotsBase.backend_package_name(be))
+        @info "selected `Plots` backend: $be_name, from $origin"
+        Pkg.status(
+            ["Plots", "PlotsBase", "RecipesBase", "RecipesPipeline", be_name];
+            mode = Pkg.PKGMODE_MANIFEST,
+            io,
+        )
     end
+    nothing
+end
 
-    # COV_EXCL_START
-    @setup_workload begin
-        load_default_backend()
-        @debug PlotsBase.backend_package_name()
-        n = length(PlotsBase._examples)
-        imports = sizehint!(Expr[], n)
-        examples = sizehint!(Expr[], 10n)
-        scratch_dir = mktempdir()
-        for i in setdiff(1:n, PlotsBase._backend_skips[backend_name()], PlotsBase._animation_examples)
-          PlotsBase._examples[i].external && continue
-          (imp = PlotsBase._examples[i].imports) ≡ nothing || push!(imports, PlotsBase.replace_module(imp))
-          func = gensym(string(i))
-          push!(
-              examples,
-              quote
-                  $func() = begin  # evaluate each example in a local scope
-                      $(PlotsBase._examples[i].exprs)
-                      $i == 1 || return  # only for one example
-                      fn = joinpath(scratch_dir, tempname())
-                      pl = current()
-                      show(devnull, pl)
-                      # FIXME: pgfplotsx requires bug
-                      backend_name() ≡ :pgfplotsx && return
-                      if backend_name() ≡ :unicodeplots
-                          savefig(pl, "$fn.txt")
-                          return
-                      end
-                      showable(MIME"image/png"(), pl) && savefig(pl, "$fn.png")
-                      showable(MIME"application/pdf"(), pl) && savefig(pl, "$fn.pdf")
-                      if showable(MIME"image/svg+xml"(), pl)
-                          show(IOBuffer(), MIME"image/svg+xml"(), pl)
-                      end
-                      nothing
-                  end
-                  $func()
-              end,
-          )
-        end
-        withenv("GKSwstype" => "nul") do
-          @compile_workload begin
-              load_default_backend()
-              eval.(imports)
-              eval.(examples)
-          end
+# COV_EXCL_START
+@setup_workload begin
+    load_default_backend()
+    @debug PlotsBase.backend_package_name()
+    n = length(PlotsBase._examples)
+    imports = sizehint!(Expr[], n)
+    examples = sizehint!(Expr[], 10n)
+    scratch_dir = mktempdir()
+    for i in setdiff(
+        1:n,
+        PlotsBase._backend_skips[backend_name()],
+        PlotsBase._animation_examples,
+    )
+        PlotsBase._examples[i].external && continue
+        (imp = PlotsBase._examples[i].imports) ≡ nothing ||
+            push!(imports, PlotsBase.replace_module(imp))
+        func = gensym(string(i))
+        push!(
+            examples,
+            quote
+                $func() = begin  # evaluate each example in a local scope
+                    $(PlotsBase._examples[i].exprs)
+                    $i == 1 || return  # only for one example
+                    fn = joinpath(scratch_dir, tempname())
+                    pl = current()
+                    show(devnull, pl)
+                    # FIXME: pgfplotsx requires bug
+                    backend_name() ≡ :pgfplotsx && return
+                    if backend_name() ≡ :unicodeplots
+                        savefig(pl, "$fn.txt")
+                        return
+                    end
+                    showable(MIME"image/png"(), pl) && savefig(pl, "$fn.png")
+                    showable(MIME"application/pdf"(), pl) && savefig(pl, "$fn.pdf")
+                    if showable(MIME"image/svg+xml"(), pl)
+                        show(IOBuffer(), MIME"image/svg+xml"(), pl)
+                    end
+                    nothing
+                end
+                $func()
+            end,
+        )
+    end
+    withenv("GKSwstype" => "nul") do
+        @compile_workload begin
+            load_default_backend()
+            eval.(imports)
+            eval.(examples)
         end
-        PlotsBase.CURRENT_PLOT.nullableplot = nothing
     end
-    # COV_EXCL_STOP
+    PlotsBase.CURRENT_PLOT.nullableplot = nothing
+end
+# COV_EXCL_STOP
 
 end
diff --git a/test/preferences.jl b/test/preferences.jl
index 691666189..8178cd85b 100644
--- a/test/preferences.jl
+++ b/test/preferences.jl
@@ -11,7 +11,8 @@
 
     withenv("PLOTS_DEFAULT_BACKEND" => "unicodeplots") do
         @test_logs (:info, r".*environment variable") Plots.diagnostics(devnull)
-        @test Plots.load_default_backend() == Base.get_extension(PlotsBase, :UnicodePlotsExt).UnicodePlotsBackend()
+        @test Plots.load_default_backend() ==
+              Base.get_extension(PlotsBase, :UnicodePlotsExt).UnicodePlotsBackend()
     end
 
     @test Plots.load_default_backend() == Base.get_extension(PlotsBase, :GRExt).GRBackend()
@@ -42,7 +43,7 @@
                 @test_logs (:info, r".*Preferences") Plots.diagnostics(io)
                 @test backend() == Base.get_extension(PlotsBase, :UnicodePlotsExt).UnicodePlotsBackend()
             end
-            exit(res.n_passed == 2 ? 0 : 1)
+            exit(res.n_passed == 2 ? 0 : 123)
             """,
         )
         @test success(run(```$(Base.julia_cmd()) $script```))
@@ -55,7 +56,17 @@
         @test_logs Plots.set_default_backend!(be)  # test the absence of warnings
         rm.(Base.find_all_in_cache_path(Base.module_keys[Plots]))  # make sure the compiled cache is removed
         script = tempname()
-        write(script, "import :$pkg; using Test, Plots; @test Plots.backend_name() ≡ :$be")
+        write(
+            script,
+            """
+            import $pkg
+            using Test, Plots
+            res = @testset "Backends" begin
+                @test Plots.backend_name() ≡ :$be
+            end
+            exit(res.n_passed == 1 ? 0 : 123)
+            """,
+        )
         @test success(run(```$(Base.julia_cmd()) $script```))  # test default precompilation
     end
 
diff --git a/test/runtests.jl b/test/runtests.jl
index 746b56f41..054a40117 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,4 +1,5 @@
-const TEST_PACKAGES = strip.(split(get(ENV, "PLOTS_TEST_PACKAGES", "GR,UnicodePlots"), ","))
+const TEST_PACKAGES =
+    strip.(split(get(ENV, "PLOTS_TEST_PACKAGES", "GR,UnicodePlots,PythonPlot"), ","))
 using PlotsBase
 
 # initialize all backends