added tests

test/unit/test_stepsize.py

@@ -1,5 +1,6 @@
 import festim
 import pytest
+import numpy as np
 
 
 class TestAdapt:
@@ -36,3 +37,47 @@ def test_hit_stepsize_max(self, my_stepsize):
         my_stepsize.adapt(t=6, converged=True, nb_it=2)
         new_value = float(my_stepsize.value)
         assert new_value == my_stepsize.adaptive_stepsize["stepsize_stop_max"]
+
+def test_milestones_are_hit():
+    """Test that the milestones are hit at the correct times
+    """
+    # create a StepSize object
+    step_size = festim.Stepsize(1.0, stepsize_change_ratio=2, milestones=[1.5, 2.0, 10.3])
+
+    # set the initial time
+    t = 0.0
+
+    # create a list of times
+    times = []
+    final_time = 11.0
+
+    # loop over the time until the final time is reached
+    while t < final_time:
+        # call the adapt method being tested
+        step_size.adapt(t, nb_it=2, converged=True)
+
+        # update the time and number of iterations
+        t += float(step_size.value)
+
+        # add the current time to the list of times
+        times.append(t)
+
+    # check that all the milestones are in the list of times
+    for milestone in step_size.milestones:
+        assert any(np.isclose(milestone, times))
+
+
+def test_next_milestone():
+    """Test that the next milestone is correct for a given t value
+    """
+    # Create a StepSize object
+    step_size = festim.Stepsize(milestones=[10.0, 20.0, 30.0])
+
+    # Set t values
+    t_values = [5.0, 10.0, 30.0]
+    expected_milestones = [10.0, 20.0, None]
+
+    # Check that the next milestone is correct for each t value
+    for t, expected_milestone in zip(t_values, expected_milestones):
+        next_milestone = step_size.next_milestone(t)
+        assert np.isclose(next_milestone, expected_milestone) if expected_milestone is not None else next_milestone is None