Fix comments and move code to detect those type of errors

theano/tensor/tests/test_extra_ops.py

@@ -134,31 +134,31 @@ class TestBinCountOp(utt.InferShapeTester):
 
     def test_bincountFn(self):
         w = T.vector('w')
-        for dtype in ('int8', 'int16', 'int32', 'int64',
-                      'uint8', 'uint16', 'uint32', 'uint64'):
-            x = T.vector('x', dtype=dtype)
-
-            a = np.random.random_integers(50, size=(25)).astype(dtype)
-            weights = np.random.random((25,)).astype(config.floatX)
-
-            f1 = theano.function([x], bincount(x))
-            f2 = theano.function([x, w], bincount(x, weights=w))
-
         def ref(data, w=None, minlength=None):
             size = data.max() + 1
             if minlength:
                 size = max(size, minlength)
-                if w:
-                    out = np.zeros(size, dtype=weights.dtype)
+            if w is not None:
+                out = np.zeros(size, dtype=w.dtype)
                 for i in range(data.shape[0]):
-                        out[data[i]] += weights[i]
+                    out[data[i]] += w[i]
             else:
                 out = np.zeros(size, dtype=a.dtype)
                 for i in range(data.shape[0]):
                     out[data[i]] += 1
             return out
+        for dtype in ('int8', 'int16', 'int32', 'int64',
+                      'uint8', 'uint16', 'uint32', 'uint64'):
+            x = T.vector('x', dtype=dtype)
+
+            a = np.random.random_integers(50, size=(25)).astype(dtype)
+            weights = np.random.random((25,)).astype(config.floatX)
+
+            f1 = theano.function([x], bincount(x))
+            f2 = theano.function([x, w], bincount(x, weights=w))
+
             assert (ref(a) == f1(a)).all()
-            assert np.allclose(ref(a, w), f2(a, weights))
+            assert np.allclose(ref(a, weights), f2(a, weights))
             f3 = theano.function([x], bincount(x, minlength=55))
             f4 = theano.function([x], bincount(x, minlength=5))
             assert (ref(a, minlength=55) == f3(a)).all()