Test coverage

**Is your feature request related to a problem? Please describe.**
Add test coverage. Try to combine test coverage from unit and integrational tests

**Describe the solution you'd like**
We can try to use native coverage from mocha + chai libraries. If not, we can specify all our routes and branches manually and calculate it

**Describe alternatives you've considered**
Perhapse some 3d part libraries can halp for that

**Additional context**
Priority is low