#1 Write a simple test for file I/O.

Makefile

@@ -1,3 +1,6 @@
+test:
+	nosetests
+
 install:
 	pip install tfr
 

tests/files_test.py

@@ -0,0 +1,32 @@
+import numpy as np
+import os
+import tempfile
+
+# Note that nose prepends the project directory to the sys.path so that we
+# do not import from the system-wide package!
+
+from tfr import files
+
+
+def test_array_should_be_saved_to_a_file():
+    fs = 1000
+    x = sine_wave(5.0, fs)
+    with tempfile.NamedTemporaryFile(delete=True) as tmpfile:
+        file_name = tmpfile.name
+        files.save_wav(x, file_name, fs=fs)
+        assert os.path.exists(file_name)
+
+def test_array_should_be_loaded_from_a_file():
+    fs = 1000
+    x = sine_wave(5.0, fs)
+    with tempfile.NamedTemporaryFile(delete=False) as tmpfile:
+        file_name = tmpfile.name
+        files.save_wav(x, file_name, fs=fs)
+        x_loaded, fs_loaded = files.load_wav(file_name)
+
+        assert fs_loaded == fs
+        # 16-bit quantization error is OK
+        assert np.allclose(x_loaded, x, atol=(1 / (((2**15)) - 1)))
+
+def sine_wave(duration, fs):
+    return np.sin(np.linspace(0, duration, duration * fs))