Add more tests

[CoolCat467]

At the moment, only htmlgen has tests. This opens the door to things not working as intended if there are differences in how different versions of python work, as we saw in #35. It would be great if we had tests written for more of the codebase.

Edit:
Potentially helpful links:
Testing in Quart
Migrating from Flask

[prashant226]

please assign this to me

[CoolCat467]

No need to assign, just raise PR

[mohitahlawat2001]

I also want to add tests

[CoolCat467]

I also want to add tests

@mohitahlawat2001 Sure thing, go for it!