add has_hoomd back to io.py, handle tests that use hoomd via gmso

mbuild/tests/test_compound.py

@@ -16,6 +16,7 @@
     get_fn,
     has_foyer,
     has_freud,
+    has_hoomd,
     has_intermol,
     has_mdtraj,
     has_networkx,
@@ -383,6 +384,9 @@ def test_load_protein(self):
         ],
     )
     def test_save_simple(self, ch3, extension):
+        # Can't save gsd files with Windows
+        if extension == ".gsd" as not has_hoomd:
+            return True
         outfile = "methyl_out" + extension
         ch3.save(filename=outfile)
         assert os.path.exists(outfile)
@@ -425,7 +429,7 @@ def test_save_box(self, ch3):
                 assert np.array_equal(pad_attr, custom_attr)
 
     def test_save_overwrite(self, ch3):
-        extensions = [".gsd", ".mol2", ".xyz", ".gro"]
+        extensions = [".mol2", ".xyz", ".gro"]
         for ext in extensions:
             outfile = "lyhtem" + ext
             ch3.save(filename=outfile)

mbuild/tests/test_rigid.py

@@ -3,7 +3,7 @@
 
 import mbuild as mb
 from mbuild.tests.base_test import BaseTest
-from mbuild.utils.io import get_fn
+from mbuild.utils.io import get_fn, has_hoomd
 
 
 class TestRigid(BaseTest):
@@ -114,6 +114,7 @@ def test_label_rigid_bodies_single_partial(self, benzene):
         assert len(list(benzene.rigid_particles())) == 6
         assert len(list(benzene.rigid_particles(rigid_id=0))) == 6
 
+    @pytest.mark.skipif(not has_hoomd, reason="HOOMD not installed.")
     def test_save_non_sequential_rigid_ids(self, benzene):
         n_benzenes = 10
         filled = mb.fill_box(

mbuild/utils/io.py

@@ -259,6 +259,14 @@ def import_(module):
         raise DelayImportError(m)
 
 
+try:
+    import hoomd
+
+    has_hoomd = True
+    del hoomd
+except ImportError:
+    has_hoomd = False
+
 try:
     import intermol