Reduce duplicate test code with centralized TEST_FILE_PATH constant

[Copilot]

Problem

Test files throughout the codebase contained significant code duplication with the same path construction pattern repeated 30+ times:

import os
import kinisi

file_path = os.path.join(os.path.dirname(kinisi.__file__), 'tests/inputs/example_XDATCAR.gz')

This approach had several drawbacks:

• Verbose and repetitive code across multiple test files
• Difficult to maintain if the test data location changes
• Mixed use of os.path instead of modern pathlib

Solution

Implemented @PythonFZ's suggestion to create a centralized TEST_FILE_PATH constant:

1. Added a constant in kinisi/tests/__init__.py:

from pathlib import Path

TEST_FILE_PATH = Path(__file__).parent / 'inputs'

2. Updated all 9 test files to import and use this constant:

from kinisi.tests import TEST_FILE_PATH

# Now much cleaner:
file_path = TEST_FILE_PATH / 'example_XDATCAR.gz'
msd_load = sc.io.load_hdf5(TEST_FILE_PATH / 'example_msd2.hdf5')

Benefits

• Single source of truth: Test file paths are defined in one place
• Reduced duplication: Eliminated 30+ instances of the same pattern
• Cleaner code: Shorter, more readable path references using pathlib's / operator
• Better maintainability: Easier to update test data location if needed in the future
• Modern approach: Uses pathlib.Path instead of os.path operations

Changes

• Created TEST_FILE_PATH constant in kinisi/tests/__init__.py
• Updated 9 test files: test_analyzer.py, test_ase.py, test_conductivity_analyzer.py, test_diffusion.py, test_diffusion_analyzer.py, test_jump_diffusion_analyzer.py, test_mdanalysis.py, test_parser.py, test_pymatgen.py
• Removed unnecessary kinisi module imports where only used for path construction
• Net change: 49 insertions(+), 50 deletions(-) - actually reduced total lines of code

Co-authored-by: PythonFZ 46721498+PythonFZ@users.noreply.github.com

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Reduce duplicate test code</issue_title>
<issue_description>@PythonFZ has suggested the following as a way to reduce code duplication in tests.

from pathlib import Path

TEST_FILE_PATH = Path(__file__).parent / "inputs"

def test_():
   sc.io.load_hdf5(TEST_FILE_PATH / "example_msd2.hdf5")
```</issue_description>

## Comments on the Issue (you are @copilot in this section)

<comments>
</comments>

Fixes #190

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[github-actions]

☂️ Python Coverage

current status: ✅

Overall Coverage

Lines	Covered	Coverage	Threshold	Status
1941	1844	95%	0%	🟢

New Files

No new covered files...

Modified Files

File	Coverage	Status
kinisi/tests/_init_.py	100%	🟢
kinisi/tests/test_analyzer.py	100%	🟢
kinisi/tests/test_ase.py	100%	🟢
kinisi/tests/test_conductivity_analyzer.py	100%	🟢
kinisi/tests/test_diffusion.py	100%	🟢
kinisi/tests/test_diffusion_analyzer.py	100%	🟢
kinisi/tests/test_jump_diffusion_analyzer.py	100%	🟢
kinisi/tests/test_mdanalysis.py	100%	🟢
kinisi/tests/test_parser.py	100%	🟢
kinisi/tests/test_pymatgen.py	100%	🟢
TOTAL	100%	🟢

updated for commit: 9a87be7 by action🐍

[PythonFZ]

LGTM