Unit test does not cover locally imported packages

Question

I am new to golang and trying to understand how i can make this scenario work?

Here is my structure GOPATH set to /Users/xyz/project

/Users/xyz/project/src/main.go // import calculator and call SUM with two integeres
/Users/xyz/project/src/main_test.go // test function
/Users/xyz/project/src/calculator/sum.go // SUM function (add two integers)

i have a main go file that imports "calculator" which is a local packages. When i run

go test -cover

it only gives the coverage of main but not for the package "calculator" imported by main. i know i can write a test inside calculator and that would do the trick but is there any way possible to get the coverage of locally imported package from main?

Bigger Context - The reason i want to do this is because i have a micro service written in go using gin framework and i want to spin it up as a service and make http calls and further see how the coverage looks like (like component test). I can easily spin it up by writing a main_test go file which starts the service but i am not getting the coverage of the imported packages.

Answer 1

Finally found response here. looks like go has a test binary that can be used https://www.elastic.co/blog/code-coverage-for-your-golang-system-tests