test suite

[wingkwong]

as the project grows, we need to some tests to make sure the upcoming changes won't break the existing ones.

[VishakhaSainani]

@wingkwong Can you elaborate in detail?

[wingkwong]

@VishakhaSainani basically we need all features working as expected. The tests can be run locally. Also we should run it on CI pipeline (Github Action) to make sure the new changes won't break the existing features.