test receiver error

amodem/recv.py

@@ -256,10 +256,12 @@ def main(args):
     size = 0
     signal, amplitude = detect(signal, config.Fc)
     bits = receive(signal, modem.freqs, gain=1.0/amplitude)
+    success = False
     try:
         for chunk in decode(bits):
             args.output.write(chunk)
             size = size + len(chunk)
+        success = True
     except Exception:
         log.exception('Decoding failed')
 
@@ -279,6 +281,7 @@ def main(args):
                       '$F_c = {} Hz$'.format(freq))
 
     pylab.show()
+    return success
 
 
 def constellation(y, symbols, title):

tests/test_full.py

@@ -19,7 +19,7 @@ class Args(object):
         self.__dict__.update(kwargs)
 
 
-def run(size, chan=None, df=0):
+def run(size, chan=None, df=0, success=True):
     tx_data = os.urandom(size)
     tx_audio = BytesIO()
     send.main(Args(silence_start=1, silence_stop=1,
@@ -38,16 +38,23 @@ def run(size, chan=None, df=0):
     rx_audio = BytesIO(data)
 
     rx_data = BytesIO()
-    recv.main(Args(skip=0, input=rx_audio, output=rx_data))
+    result = recv.main(Args(skip=0, input=rx_audio, output=rx_data))
     rx_data = rx_data.getvalue()
 
-    assert rx_data == tx_data
+    assert result == success
+    if success:
+        assert rx_data == tx_data
 
 
 def test_small():
     run(1024, chan=lambda x: x)
 
 
+def test_error():
+    skip = 1 * send.config.Fs  # remove trailing silence
+    run(1024, chan=lambda x: x[:-skip], success=False)
+
+
 def test_frequency_error():
     for ppm in [0.1, 1, 10]:
         for sign in [+1, -1]:
@@ -78,4 +85,3 @@ def test_medium_noise():
 
 def test_large():
     run(54321, chan=lambda x: x)
-