Test to ensure no FutureWarning when determining Wave type

tests/test_wave.py

@@ -1,3 +1,5 @@
+import warnings
+
 import numpy as np
 
 import pytest
@@ -18,10 +20,18 @@ wave_paths = [
 
 @pytest.mark.parametrize("wave_path", wave_paths)
 def test_wave(wave_path):
-    wave = Wave(None, prefix + wave_path)
-    data = wave[:]
+    with warnings.catch_warnings(record=True) as w:
+        # Cause all warnings to always be triggered.
+        warnings.simplefilter("always")
 
-    # Audacity dithers <=16-bit WAV files upon export, creating a few bits of noise.
-    # As a result, amin(data) <= 0.
-    assert -0.01 < np.amin(data) <= 0
-    assert 0.99 < np.amax(data) <= 1
+        wave = Wave(None, prefix + wave_path)
+        data = wave[:]
+
+        # Audacity dithers <=16-bit WAV files upon export, creating a few bits of noise.
+        # As a result, amin(data) <= 0.
+        assert -0.01 < np.amin(data) <= 0
+        assert 0.99 < np.amax(data) <= 1
+
+        # check for FutureWarning (raised when determining wavfile type)
+        warns = [o for o in w if issubclass(o.category, FutureWarning)]
+        assert not [str(w) for w in warns]