Added basic unit tests

Added test_sequential_simulators to test_simulators/test_simulators.py.
Removed extra whitespace in seqential_simulator.py

Author: Chase-Grajeda

bayesflow/simulators/sequential_simulator.py

@@ -1,10 +1,7 @@
 import keras
-
 from collections.abc import Sequence
-
 from bayesflow.types import Sampler, Shape, Tensor
 from bayesflow.utils import batched_call, filter_kwargs
-
 from .simulator import Simulator
 
 

tests/test_simulators/test_simulators.py

@@ -11,3 +11,18 @@ def test_sample_is_random(simulator, batch_size):
         expected = keras.ops.size(tensor)
         actual = np.size(np.unique(array))
         assert actual == expected
+
+
+def test_sequential_simulators(sequential_two_moons, batch_size):
+    data = sequential_two_moons.sample((batch_size,))
+
+    # Test all keys are present
+    result_keys = set([key for key in data.keys()])
+    expected_keys = set(["r", "alpha", "theta", "x"])
+    assert result_keys == expected_keys
+
+    # Test correct output shapes are returned
+    assert data["r"].shape == (batch_size,)
+    assert data["alpha"].shape == (batch_size,)
+    assert data["theta"].shape == (batch_size, 2)
+    assert data["x"].shape == (batch_size, 2)