add tests

tests/test_constraints.py

@@ -99,6 +99,8 @@ def comp_constraints(solver):
         for glob_expr in global_constraints(solver):
             if not glob_expr.is_bool():
                 for rhs in [NUM_VAR, BOOL_VAR, 1, BoolVal(True)]:
+                    if comp_name == "<" and get_bounds(glob_expr)[0] >= get_bounds(rhs)[1]:
+                        continue
                     yield Comparison(comp_name, glob_expr, rhs)
 
     if solver == "z3":
@@ -149,7 +151,7 @@ def global_constraints(solver):
         -  AllDifferent, AllEqual, Circuit,  Minimum, Maximum, Element,
            Xor, Cumulative
     """
-    global_cons = [AllDifferent, AllEqual, Minimum, Maximum]
+    global_cons = [AllDifferent, AllEqual, Minimum, Maximum, NValue]
     for global_type in global_cons:
         cons = global_type(NUM_ARGS)
         if solver not in EXCLUDE_GLOBAL or cons.name not in EXCLUDE_GLOBAL[solver]:

tests/test_globalconstraints.py

@@ -614,6 +614,29 @@ def test_count_onearg(self):
                 except (NotImplementedError, NotSupportedError):
                     pass
 
+
+    def test_nvalue(self):
+
+        iv = cp.intvar(-8, 8, shape=3)
+        cnt = cp.intvar(0,10)
+
+        self.assertFalse(cp.Model(cp.all(iv == 1), cp.NValue(iv) > 1).solve())
+        self.assertTrue(cp.Model(cp.all(iv == 1), cp.NValue(iv) > cnt).solve())
+        self.assertGreater(len(set(iv.value())), cnt.value())
+
+        self.assertTrue(cp.Model(cp.NValue(iv) != cnt).solve())
+        self.assertTrue(cp.Model(cp.NValue(iv) >= cnt).solve())
+        self.assertTrue(cp.Model(cp.NValue(iv) <= cnt).solve())
+        self.assertTrue(cp.Model(cp.NValue(iv) < cnt).solve())
+        self.assertTrue(cp.Model(cp.NValue(iv) > cnt).solve())
+
+        # test nested
+        bv = cp.boolvar()
+        cons = bv == (cp.NValue(iv) <= 2)
+        def check_true():
+            self.assertTrue(cons.value())
+        cp.Model(cons).solveAll(display=check_true)
+
 class TestBounds(unittest.TestCase):
     def test_bounds_minimum(self):
         x = cp.intvar(-8, 8)