code: def test_minus_no_descent(fontsize):
      # Test special-casing of minus descent in DviFont._height_depth_of, by
      # checking that overdrawing a 1 and a -1 results in an overall height
      # equivalent to drawing either of them separately.
      mpl.style.use("mpl20")
      mpl.rcParams["font.size"] = fontsize
      heights = {}
      fig = plt.figure()
      for vals in [(1,), (-1,), (-1, 1)]:
          fig.clear()
          for x in vals:
              fig.text(0.5, 0.5, f"${x}$", usetex=True)
          fig.canvas.draw()
          # The following counts the number of non-fully-blank pixel rows.
          heights[vals] = (
              (np.array(fig.canvas.buffer_rgba())[..., 0] != 255)
              .any(axis=1)
              .sum()
          )
      assert len({*heights.values()}) == 1
  
imports: from tempfile import TemporaryFile
  import numpy
  from packaging.version import parse
  import pytest
  import matplotlib
  from matplotlib import dviread
  from matplotlib.testing import _has_tex_package
  from matplotlib.testing.decorators import check_figures_equal, image_comparison
  from matplotlib.testing._markers import needs_usetex
  import matplotlib.pyplot
label_desc: Use image node_id 6 for calling a global function with example usage: test_minus_no_descent(fontsize) without return types