fix assert_str_content_equal and add test

src/pymatgen/util/testing/__init__.py

@@ -29,7 +29,9 @@
     from pymatgen.util.typing import PathLike
 
 MODULE_DIR: Path = Path(__file__).absolute().parent
+
 STRUCTURES_DIR: Path = MODULE_DIR / ".." / "structures"
+
 TEST_FILES_DIR: Path = Path(SETTINGS.get("PMG_TEST_FILES_DIR", f"{ROOT}/../tests/files"))
 VASP_IN_DIR: str = f"{TEST_FILES_DIR}/io/vasp/inputs"
 VASP_OUT_DIR: str = f"{TEST_FILES_DIR}/io/vasp/outputs"
@@ -72,18 +74,19 @@ def get_structure(cls, name: str) -> Structure:
         return struct.copy()
 
     @staticmethod
-    def assert_str_content_equal(actual: str, expected: str) -> bool:
+    def assert_str_content_equal(actual: str, expected: str) -> None:
         """Test if two strings are equal, ignoring whitespaces.
 
         Args:
             actual (str): The string to be checked.
             expected (str): The reference string.
 
-        Returns:
-            bool
+        Raises:
+            AssertionError: When two strings are not equal.
         """
         strip_whitespace = {ord(c): None for c in string.whitespace}
-        return actual.translate(strip_whitespace) == expected.translate(strip_whitespace)
+        if actual.translate(strip_whitespace) != expected.translate(strip_whitespace):
+            raise AssertionError("Strings are not equal (whitespaces ignored).")
 
     def serialize_with_pickle(
         self,

tests/util/test_testing.py

@@ -0,0 +1,68 @@
+from __future__ import annotations
+
+import os
+
+import pytest
+
+from pymatgen.core import Structure
+from pymatgen.util.testing import (
+    FAKE_POTCAR_DIR,
+    MODULE_DIR,
+    STRUCTURES_DIR,
+    TEST_FILES_DIR,
+    VASP_IN_DIR,
+    VASP_OUT_DIR,
+    PymatgenTest,
+)
+
+
+def test_paths():
+    """Test paths provided in testing util."""
+    assert MODULE_DIR.is_dir()
+
+    assert STRUCTURES_DIR.is_dir()
+    assert [f for f in os.listdir(STRUCTURES_DIR) if f.endswith(".json")]
+
+    assert TEST_FILES_DIR.is_dir()
+    assert os.path.isdir(VASP_IN_DIR)
+    assert os.path.isdir(VASP_OUT_DIR)
+
+    assert os.path.isdir(FAKE_POTCAR_DIR)
+    assert any(f.startswith("POTCAR") for _root, _dir, files in os.walk(FAKE_POTCAR_DIR) for f in files)
+
+
+class TestPymatgenTest:
+    def test_tmp_dir(self):
+        pass
+
+    def test_get_structure(self):
+        structure = PymatgenTest.get_structure("LiFePO4")
+        assert isinstance(structure, Structure)
+
+        # TODO: need to check non-existent structure exception
+
+    def test_assert_str_content_equal(self):
+        # Cases where strings are equal
+        PymatgenTest.assert_str_content_equal("hello world", "hello world")
+        PymatgenTest.assert_str_content_equal("  hello   world  ", "hello world")
+        PymatgenTest.assert_str_content_equal("\nhello\tworld\n", "hello world")
+
+        # Test whitespace handling
+        PymatgenTest.assert_str_content_equal("", "")
+        PymatgenTest.assert_str_content_equal("  ", "")
+        PymatgenTest.assert_str_content_equal("hello\n", "hello")
+        PymatgenTest.assert_str_content_equal("hello\r\n", "hello")
+        PymatgenTest.assert_str_content_equal("hello\t", "hello")
+
+        # Cases where strings are not equal
+        with pytest.raises(AssertionError, match="Strings are not equal"):
+            PymatgenTest.assert_str_content_equal("hello world", "hello_world")
+
+        with pytest.raises(AssertionError, match="Strings are not equal"):
+            PymatgenTest.assert_str_content_equal("hello", "hello world")
+
+    def test_serialize_with_pickle(self):
+        pass
+
+    def test_assert_msonable(self):
+        pass