added test for to_molecule

vermouth/tests/test_molecule.py

@@ -21,6 +21,7 @@
 import pytest
 import vermouth
 import vermouth.molecule
+import vermouth.forcefield
 from vermouth.molecule import Interaction, Molecule
 
 from .molecule_strategies import random_molecule, random_block, random_link
@@ -1243,3 +1244,29 @@ def test_str_method(mol, moltype):
  assert '{} {}'.format(len(interactions), itype) in found
  else:
  assert '{} {}'.format(0, itype) not in found
+
+def test_to_molecule():
+ """
+ Test if the to molecule function gives
+ expected results.
+ """
+ force_field = vermouth.forcefield.ForceField("test")
+ test_block = vermouth.molecule.Block()
+ test_block.add_edges_from([('A','B'), ('B','C')])
+ test_block.interactions["bonds"] = [
+ Interaction(atoms=('A', 'B'),
+ parameters=['a', '0.2', '200'],
+ meta={'a': 0}),
+ Interaction(atoms=('B', 'C'),
+ parameters=['a', '0.1', '300'],
+ meta={'b': 1}),]
+
+ molecule = test_block.to_molecule()
+
+ ref_bonds = [ Interaction(atoms=(0, 1),
+ parameters=['a', '0.2', '200'],
+ meta={'a': 0}),
+ Interaction(atoms=(1, 2),
+ parameters=['a', '0.1', '300'],
+ meta={'b': 1}),]
+ assert ref_bonds == molecule.interactions['bonds']