added test for dataset shuffling

tests/test_dataset.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import random
+
 import numpy as np
 import pytest
 import torch
@@ -17,6 +19,7 @@
 @pytest.fixture()
 def structure_data() -> StructureData:
     """Create a graph with 3 nodes and 3 directed edges."""
+    random.seed(42)
     structures, energies, forces, stresses, magmoms, structure_ids = (
         [],
         [],
@@ -25,15 +28,15 @@ def structure_data() -> StructureData:
         [],
         [],
     )
-    for _ in range(100):
+    for index in range(100):
         struct = NaCl.copy()
         struct.perturb(0.1)
         structures.append(struct)
         energies.append(np.random.random(1))
         forces.append(np.random.random([2, 3]))
         stresses.append(np.random.random([3, 3]))
         magmoms.append(np.random.random([2, 1]))
-        structure_ids.append("tmp_id")
+        structure_ids.append(index)
     return StructureData(
         structures=structures,
         energies=energies,
@@ -47,7 +50,8 @@ def structure_data() -> StructureData:
 def test_structure_data(structure_data: StructureData) -> None:
     get_one = structure_data[0]
     assert isinstance(get_one[0], CrystalGraph)
-    assert get_one[0].mp_id == "tmp_id"
+    assert isinstance(get_one[0].mp_id, int)
+    assert get_one[0].mp_id == 42
     assert isinstance(get_one[1], dict)
     assert isinstance(get_one[1]["e"], torch.Tensor)
     assert isinstance(get_one[1]["f"], torch.Tensor)
@@ -85,3 +89,36 @@ def test_structure_data_inconsistent_length():
         == f"Inconsistent number of structures and labels: {len(structures)=}, "
         f"{len(forces)=}"
     )
+
+
+def test_dataset_no_shuffling():
+    structures, energies, forces, stresses, magmoms, structure_ids = (
+        [],
+        [],
+        [],
+        [],
+        [],
+        [],
+    )
+    for index in range(100):
+        struct = NaCl.copy()
+        struct.perturb(0.1)
+        structures.append(struct)
+        energies.append(np.random.random(1))
+        forces.append(np.random.random([2, 3]))
+        stresses.append(np.random.random([3, 3]))
+        magmoms.append(np.random.random([2, 1]))
+        structure_ids.append(index)
+    structure_data = StructureData(
+        structures=structures,
+        energies=energies,
+        forces=forces,
+        stresses=stresses,
+        magmoms=magmoms,
+        structure_ids=structure_ids,
+        shuffle=False,
+    )
+
+    assert structure_data[0][0].mp_id == 0
+    assert structure_data[1][0].mp_id == 1
+    assert structure_data[2][0].mp_id == 2