[Good First Issue] List required of functions to create tests for #103

Currently, the tests/ directory does not test against every other function to give expected results.

The work towards testing should be done in these phases,

1. List functions that need to have unit tests created
2. Create a mechanism to fetch GeoJSONs from the API that are guaranteed the right results to test against
3. Assert the functionality is working as expected with the fetched data

Help is required with the 1st step. Having a list of unit tests to implement would be great - not everything can be tested.