Add test for LIKE n BUT

Author: paulromano

src/openmc_mcnp_adapter/parse.py

@@ -13,7 +13,7 @@
 _KEYWORDS = [
     r'\*?trcl', r'\*?fill', 'tmp', 'u', 'lat',
     'imp:.', 'vol', 'pwt', 'ext:.', 'fcl', 'wwn', 'dxc', 'nonu', 'pd',
-    'elpt', 'cosy', 'bflcl', 'unc',
+    'elpt', 'cosy', 'bflcl', 'unc', 'mat', 'rho',
     'pmt'  # D1SUNED-specific
 ]
 _ANY_KEYWORD = '|'.join(f'(?:{k})' for k in _KEYWORDS)

tests/test_geometry.py

@@ -1,6 +1,6 @@
 from textwrap import dedent
 
-from pytest import mark
+from pytest import mark, approx
 from openmc_mcnp_adapter import mcnp_str_to_model
 
 
@@ -9,8 +9,8 @@ def test_cell_complement(whitespace):
     # Cell 2 corresponds to r < 2 intersected with z > 0
     mcnp_str = dedent(f"""
     title
-    100  1.0  +1 : -2
-    2    1.0  #{whitespace}100
+    100  1 1.0  +1 : -2
+    2    1 1.0  #{whitespace}100
 
     1  so 2.0
     2  pz 0.0
@@ -27,3 +27,31 @@ def test_cell_complement(whitespace):
     assert (0., 0., 2.01) not in cell.region
     assert (1., 1., 1.) in cell.region
     assert (2., 0., 1.) not in cell.region
+
+
+def test_likenbut():
+    mcnp_str = dedent("""
+    title
+    1   1 -1.0  -1
+    2   LIKE 1 BUT MAT=2 RHO=-2.0 TRCL=(2.0 0.0 0.0)
+
+    1   so 1.0
+
+    m1   1001.80c  1.0
+    m2   1002.80c  1.0
+    """)
+    model = mcnp_str_to_model(mcnp_str)
+    cell = model.geometry.get_all_cells()[2]
+
+    # Material should be changed to m2
+    mat = cell.fill
+    assert 'H2' in mat.get_nuclide_densities()
+
+    # Density should be 2.0 g/cm3
+    assert mat.get_mass_density() == approx(2.0)
+
+    # Points should correspond to sphere of r=1 centered at (2, 0, 0)
+    assert (2.0, 0.0, 0.0) in cell.region
+    assert (0.0, 0.0, 0.0) not in cell.region
+    assert (2.0, 0.9, 0.0) in cell.region
+    assert (2.0, 1.1, 0.0) not in cell.region