Fixed SVG-as-text image comparison tests.

tfpf · tfpf · commit fb31d90a706d · 2022-06-26T18:10:17.000+05:30
SVG-as-text tests make make the figure background transparent, but the underlying colour is black. Before the expected and actual images are compared, they are converted from RGBA to RGB, which makes them both completely black (since the text is also black). As a result, the test passes even if the expected and actual images differ. Making the text white solves this problem.
diff --git a/lib/matplotlib/tests/baseline_images/test_mathtext/mathtext0_cm_00.svg b/lib/matplotlib/tests/baseline_images/test_mathtext/mathtext0_cm_00.svg
@@ -8,7 +8,7 @@
  <g id="figure_1">
   <g id="text_1">
    <!-- $-$- -->
-   <g transform="translate(182.16 30.31125)">
+   <g style="fill: #ffffff" transform="translate(182.16 30.31125)">
     <text>
      <tspan style="font: 12px 'cmsy10'" x="0" y="-0.234375">¡</tspan>
      <tspan style="font: 12px 'DejaVu Sans'" x="9.322266" y="-0.234375">-</tspan>
diff --git a/lib/matplotlib/tests/baseline_images/test_mathtext/mathtext0_dejavusans_00.svg b/lib/matplotlib/tests/baseline_images/test_mathtext/mathtext0_dejavusans_00.svg
@@ -8,7 +8,7 @@
  <g id="figure_1">
   <g id="text_1">
    <!-- $-$- -->
-   <g transform="translate(181.8 30.31125)">
+   <g style="fill: #ffffff" transform="translate(181.8 30.31125)">
     <text>
      <tspan style="font: 12px 'DejaVu Sans'" x="0 10.054688" y="-0.734375">−-</tspan>
     </text>
diff --git a/lib/matplotlib/tests/test_mathtext.py b/lib/matplotlib/tests/test_mathtext.py
@@ -216,6 +216,7 @@ def test_mathtext_rendering(baseline_images, fontset, index, text):
 def test_mathtext_rendering_svgastext(baseline_images, fontset, index, text):
     mpl.rcParams['mathtext.fontset'] = fontset
     mpl.rcParams['svg.fonttype'] = 'none'  # Minimize image size.
+    mpl.rcParams['text.color'] = 'white'
     fig = plt.figure(figsize=(5.25, 0.75))
     fig.patch.set(visible=False)  # Minimize image size.
     fig.text(0.5, 0.5, text,
