fix error message check

Author: sbillinge

Diff for: tests/test_diffraction_objects.py

@@ -523,9 +523,9 @@ def test_id_setter_error(do_minimal):
 def test_xarray_yarray_length_mismatch():
     with pytest.raises(
         ValueError,
-        match="'xarray' and 'yarray' must have the same length. "
-        "Please re-initialize 'DiffractionObject' or re-run the method 'input_data' "
-        "with 'xarray' and 'yarray' of identical length",
+        match="'xarray' and 'yarray' are different lengths.  "
+        "They must correspond to each other and have the same length. Please "
+        "re-initialize 'DiffractionObject'with valid 'xarray' and 'yarray's"
     ):
         DiffractionObject(
             xarray=np.array([1.0, 2.0]), yarray=np.array([0.0, 0.0, 0.0]), xtype="tth", wavelength=1.54