Add test coverage for missing general_calculations in MolecularData.load

[mhucka]

This change removes the pragma: nocover and the associated TODO in src/openfermion/chem/molecular_data.py by adding a test case in src/openfermion/chem/molecular_data_test.py that triggers the branch where general_calculations_keys or general_calculations_values are missing from the HDF5 file.

[gemini-code-assist]

Code Review

This pull request removes coverage pragmas and adds a test case for scenarios where general calculations are missing from the HDF5 file. Feedback suggests initializing general_calculations as an empty dictionary rather than None to prevent potential AttributeError during save operations. Additionally, the new test case should be refactored to ensure proper file cleanup and remove redundant initialization calls.

[mhucka]

/gemini review

[gemini-code-assist]

Code Review

This pull request modifies MolecularData.load to initialize general_calculations as an empty dictionary when keys are missing and introduces a test case for this behavior. Feedback highlights a remaining edge case that could cause an AttributeError and suggests a more robust initialization. Furthermore, it is recommended to use tempfile.TemporaryDirectory in the tests to ensure compatibility with Windows systems.

[mhucka]

/gemini review

[gemini-code-assist]

Code Review

This pull request updates the MolecularData.load method to initialize general_calculations as an empty dictionary instead of None when the corresponding keys are missing from the HDF5 file. It also adds a unit test to verify this behavior using a temporary HDF5 file. A review comment suggests that the current implementation still misses a case where the keys exist but are empty, which could lead to an AttributeError, and provides a code suggestion to handle both scenarios.