refactor: throw a ValueError instead of an AssertionError when numeri…

…cal constrasts have incorrect shapes

pydeseq2/ds.py

@@ -176,9 +176,10 @@ def __init__(
                 The "contrast" argument must be provided."""
             )
         elif isinstance(contrast, np.ndarray):
-            assert (
-                contrast.shape[0] == self.dds.obsm["design_matrix"].shape[1]
-            ), "The contrast vector must have the same length as the design matrix."
+            if contrast.shape[0] != self.dds.obsm["design_matrix"].shape[1]:
+                raise ValueError(
+                    "The contrast vector must have the same length as the design matrix."
+                )
             self.contrast = contrast
             self.contrast_vector = contrast
         else:

tests/test_edge_cases.py

@@ -244,6 +244,10 @@ def test_contrast():
     with pytest.raises(ValueError):
         DeseqStats(dds, contrast=["condition", "C", "B"])
 
+    # Numerical contrast with the wrong number of elements
+    with pytest.raises(ValueError):
+        DeseqStats(dds, contrast=np.array([0, 0, 0, 1]))
+
 
 def test_cooks_not_refitted():
     """Test that an AttributeError is thrown when a `DeseqStats` object is initialized