def test_same_interactions(left, right, expected):
"""
Test that Molecule.same_interactions works as expected.
"""
left_mol = Molecule()
left_mol.interactions = left
right_mol = Molecule()
right_mol.interactions = right
assert left_mol.same_interactions(right_mol) == expected
assert right_mol.same_interactions(left_mol) == expected
def test_pre_post_section_lines(pre_meta, post_meta):
"""
:func:`vermouth.gmx.itp.write_molecule_itp` writes pre and post section lines.
If `pre_meta` or `post_meta` is `True`, then "pre_section_lines" or
"post_section_lines", respectively, is read from `molecule.meta`, otherwise
it is passed as an argument.
"""
molecule = Molecule(nrexcl=1)
molecule.add_nodes_from((
(0, {
'atype': 'Q5',
'resid': 1,
'resname': 'VAL',
'atomname': 'BB',
'charge_group': 1,
'charge': 1,
}),
(1, {
'atype': 'Q5',
'resid': 1,
'resname': 'VAL',
'atomname': 'BB',
'charge_group': 1,
'charge': 1,
}),
(2, {
'atype': 'Q5',
'resid': 1,
'resname': 'VAL',
'atomname': 'BB',
'charge_group': 1,
'charge': 1,
}),
))
# The molecule has 6 interaction sections. The sections are names
# "interaction_<joint>_<part>", where <joint> can be "with" or "only", and
# <part> can be "pre", "post", or "pre_post". The <part> indicates what
# pre_section_lines and post_section_lines are defined for the section.
# When <joint> in "with", then the section contains 2 interactions in
# addition to the pre- and post- lines. When <joint> is "only", then the
# section only has the pre/post lines defined, and no interactions.
parts = ('pre', 'post', 'pre_post')
molecule.interactions = {}
for part in parts:
name = 'interaction_with_{}'.format(part)
molecule.interactions[name] = [
Interaction(atoms=[0, 1], parameters=[name], meta={}),
Interaction(atoms=[1, 2], parameters=[name], meta={}),
]
pre_section_lines = {
'atoms': ['test_atoms_0', 'test_atoms_1'],
'interaction_with_pre': ['test_pre_0', 'test_pre_1', 'test_pre_2'],
'interaction_with_pre_post': ['test_pre_post_0'],
'interaction_only_pre': ['test_pre_only_0', 'test_pre_only_1'],
'interaction_only_pre_post':
['test_prepost_only_0', 'test_prepost_only_1'],
}
post_section_lines = {
'atoms': ['after_atoms_0'],
'interaction_with_post': ['after_post_0', 'after_post_1'],
'interaction_with_pre_post': ['after_pre_post_0'],
'interaction_only_post': ['after_post_only_0', 'after_post_only_1'],
'interaction_only_pre_post': ['after_prepost_only_0'],
}
expected_segments = [
"""
[ atoms ]
test_atoms_0
test_atoms_1
1 Q5 1 VAL BB 1 1
2 Q5 1 VAL BB 1 1
3 Q5 1 VAL BB 1 1
after_atoms_0
""",
"""
[ interaction_with_pre ]
test_pre_0
test_pre_1
test_pre_2
1 2 interaction_with_pre
2 3 interaction_with_pre
""",
"""
[ interaction_with_post ]
1 2 interaction_with_post
2 3 interaction_with_post
""",
"""
[ interaction_with_pre_post ]
test_pre_post_0
1 2 interaction_with_pre_post
2 3 interaction_with_pre_post
after_pre_post_0
""",
"""
[ interaction_only_pre ]
test_pre_only_0
test_pre_only_1
""",
"""
[ interaction_only_post ]
after_post_only_0
after_post_only_1
""",
"""
[ interaction_only_pre_post ]
test_prepost_only_0
test_prepost_only_1
after_prepost_only_0
""",
]
if post_meta:
arg_post = post_section_lines
molecule.meta['post_section_lines'] = 'invalid'
else:
arg_post = None
molecule.meta['post_section_lines'] = post_section_lines
if pre_meta:
arg_pre = pre_section_lines
molecule.meta['pre_section_lines'] = 'invalid'
else:
arg_pre = None
molecule.meta['pre_section_lines'] = pre_section_lines
outfile = io.StringIO()
write_molecule_itp(molecule,
outfile,
moltype='test',
post_section_lines=arg_post,
pre_section_lines=arg_pre)
itp_content = outfile.getvalue()
# This could be a assert all(...), but it makes it more difficult to
# understant what is happening in case of a failure.
for segment in expected_segments:
assert textwrap.dedent(segment)[:-1] in itp_content
