Added tests for add_or_update function

[Sai-ganesh-0004]

Description

This PR adds unit tests to verify the functionality of the add_or_update_file function in allFileMetadata.py. These tests ensure that:

• New file metadata is added correctly.
• Metadata is updated when a file with the same hash already exists in the store.

The tests follow the project’s guidelines and use pytest for implementation.

• Fixes Write Tests for add_or_update_file Function #4

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Tests update

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes
• I have maintained a clean commit history by using the necessary Git commands
• I have checked that my code does not cause any merge conflicts

Screenshots (if applicable)

[Kota-Karthik]

@Sai-ganesh-0004
LGTM!
thank you!