test: created test for specgram Fs is none

Stefan Mitic · Stefan Mitic · commit cc753e7053f2 · 2020-03-10T11:28:57.000-04:00
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -4166,6 +4166,17 @@ def test_specgram_angle():
                                 scale="dB")
 
 
+def test_specgram_fs_none():
+    """ Test axes.specgram when Fs is None, should not throw error """
+    try:
+        spec, freqs, t, im = plt.specgram(np.ones(300), Fs=None)
+    except Exception as e:
+        raise pytest.fail("DID RAISE {0}".format(e))
+
+    xmin, xmax, freq0, freq1 = im.get_extent()
+    assert xmin == 32 and xmax == 96
+
+
 @image_comparison(
     ["psd_freqs.png", "csd_freqs.png", "psd_noise.png", "csd_noise.png"],
     remove_text=True, tol=0.002)
