Update doc/api/testing_api.rst

story645 · timhoffm · story645 · commit 291541afca2e · 2024-09-25T17:25:44.000-04:00
Co-authored-by: Tim Hoffmann &lt;2836374+timhoffm@users.noreply.github.com&gt;
diff --git a/doc/api/testing_api.rst b/doc/api/testing_api.rst
@@ -39,8 +39,9 @@
    :show-inheritance:
 
 
-Data container testing fixtures
+Testing with optional dependencies
 ==================================
+For more information on fixtures, see :external+pytest:ref:`pytest fixtures <about-fixtures>`.
 
 .. autofunction:: matplotlib.testing.conftest.pd
 .. autofunction:: matplotlib.testing.conftest.xr
diff --git a/lib/matplotlib/testing/conftest.py b/lib/matplotlib/testing/conftest.py
@@ -82,7 +82,20 @@ def mpl_test_settings(request):
 
 @pytest.fixture
 def pd():
-    """Fixture to import and configure pandas."""
+    """
+    Fixture to import and configure pandas.
+
+    Example
+    -------
+    Instead of importing pandas in the test file, request the pandas fixture by
+    passing in `pd` as an argument to the testing function ::
+
+        def test_matshow_pandas(pd):
+
+            df = pd.DataFrame({'x':[1,2,3], 'y':[4,5,6]})
+            im = plt.figure().subplots().matshow(df)
+            np.testing.assert_array_equal(im.get_array(), df)
+    """
     pd = pytest.importorskip('pandas')
     try:
         from pandas.plotting import (
@@ -95,6 +108,20 @@ def pd():
 
 @pytest.fixture
 def xr():
-    """Fixture to import xarray."""
+    """
+    Fixture to import xarray.
+
+    Example
+    -------
+    Instead of importing xarray in the test file, request the xarray fixture by
+    passing in `xr` as an argument to the testing function ::
+
+        def test_imshow_xarray(xr):
+
+            ds = xr.DataArray(np.random.randn(2, 3))
+            im = plt.figure().subplots().imshow(ds)
+            np.testing.assert_array_equal(im.get_array(), ds)
+    """
+
     xr = pytest.importorskip('xarray')
     return xr
