From 22cca93603fed52fd82b9fb59a7a0237b19838f1 Mon Sep 17 00:00:00 2001
From: Richard Berger <richard.berger@temple.edu>
Date: Mon, 5 Oct 2020 17:34:08 -0400
Subject: [PATCH] Add tests for neighbor list API

---
 python/lammps.py                   |  2 +-
 unittest/python/python-commands.py | 43 ++++++++++++++++++++++++++++++
 unittest/python/python-numpy.py    | 43 ++++++++++++++++++++++++++++++
 3 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/python/lammps.py b/python/lammps.py
index 1f38dd7772..2e7b9ab86f 100644
--- a/python/lammps.py
+++ b/python/lammps.py
@@ -1587,7 +1587,7 @@ class lammps(object):
     """
     if idx < 0:
         return None
-    return NeighList(self.lmp, idx)
+    return NeighList(self, idx)
 
   # -------------------------------------------------------------------------
 
diff --git a/unittest/python/python-commands.py b/unittest/python/python-commands.py
index 0b853a207e..6bd5a2a247 100644
--- a/unittest/python/python-commands.py
+++ b/unittest/python/python-commands.py
@@ -85,6 +85,49 @@ create_atoms 1 single &
         natoms = self.lmp.get_natoms()
         self.assertEqual(natoms,2)
 
+    def testNeighborList(self):
+        self.lmp.command("units lj")
+        self.lmp.command("atom_style atomic")
+        self.lmp.command("atom_modify map array")
+        self.lmp.command("boundary f f f")
+        self.lmp.command("region box block 0 2 0 2 0 2")
+        self.lmp.command("create_box 1 box")
+
+        x = [
+          1.0, 1.0, 1.0,
+          1.0, 1.0, 1.5
+        ]
+
+        types = [1, 1]
+
+        self.assertEqual(self.lmp.create_atoms(2, id=None, type=types, x=x), 2)
+        nlocal = self.lmp.extract_global("nlocal")
+        self.assertEqual(nlocal, 2)
+
+        self.lmp.command("mass 1 1.0")
+        self.lmp.command("velocity all create 3.0 87287")
+        self.lmp.command("pair_style lj/cut 2.5")
+        self.lmp.command("pair_coeff 1 1 1.0 1.0 2.5")
+        self.lmp.command("neighbor 0.1 bin")
+        self.lmp.command("neigh_modify every 20 delay 0 check no")
+
+        self.lmp.command("run 0")
+
+        self.assertEqual(self.lmp.find_pair_neighlist("lj/cut"), 0)
+        nlist = self.lmp.get_neighlist(0)
+        self.assertEqual(len(nlist), 2)
+        atom_i, numneigh_i, neighbors_i = nlist[0]
+        atom_j, numneigh_j, _ = nlist[1]
+
+        self.assertEqual(atom_i, 0)
+        self.assertEqual(atom_j, 1)
+
+        self.assertEqual(numneigh_i, 1)
+        self.assertEqual(numneigh_j, 0)
+
+        self.assertEqual(1, neighbors_i[0])
+
+
 ##############################
 if __name__ == "__main__":
     unittest.main()
diff --git a/unittest/python/python-numpy.py b/unittest/python/python-numpy.py
index 3c8ff9f512..46794590f4 100644
--- a/unittest/python/python-numpy.py
+++ b/unittest/python/python-numpy.py
@@ -135,5 +135,48 @@ class PythonNumpy(unittest.TestCase):
         self.assertTrue((x[1] == (1.0, 1.0, 1.5)).all())
         self.assertEqual(len(v), 2)
 
+    def testNeighborList(self):
+        self.lmp.command("units lj")
+        self.lmp.command("atom_style atomic")
+        self.lmp.command("atom_modify map array")
+        self.lmp.command("boundary f f f")
+        self.lmp.command("region box block 0 2 0 2 0 2")
+        self.lmp.command("create_box 1 box")
+
+        x = [
+          1.0, 1.0, 1.0,
+          1.0, 1.0, 1.5
+        ]
+
+        types = [1, 1]
+
+        self.assertEqual(self.lmp.create_atoms(2, id=None, type=types, x=x), 2)
+        nlocal = self.lmp.extract_global("nlocal")
+        self.assertEqual(nlocal, 2)
+
+        self.lmp.command("mass 1 1.0")
+        self.lmp.command("velocity all create 3.0 87287")
+        self.lmp.command("pair_style lj/cut 2.5")
+        self.lmp.command("pair_coeff 1 1 1.0 1.0 2.5")
+        self.lmp.command("neighbor 0.1 bin")
+        self.lmp.command("neigh_modify every 20 delay 0 check no")
+
+        self.lmp.command("run 0")
+
+        self.assertEqual(self.lmp.find_pair_neighlist("lj/cut"), 0)
+        nlist = self.lmp.numpy.get_neighlist(0)
+        self.assertEqual(len(nlist), 2)
+        atom_i, neighbors_i = nlist[0]
+        atom_j, neighbors_j = nlist[1]
+
+        self.assertEqual(atom_i, 0)
+        self.assertEqual(atom_j, 1)
+
+        self.assertEqual(len(neighbors_i), 1)
+        self.assertEqual(len(neighbors_j), 0)
+
+        self.assertIn(1, neighbors_i)
+        self.assertNotIn(0, neighbors_j)
+
 if __name__ == "__main__":
     unittest.main()