Golang testing: “no test files”

Files containing tests should be called name_test, with the _test suffix. They should be alongside the code that they are testing.

To run the tests recursively call go test -v ./...

From How to Write Go Code:

You write a test by creating a file with a name ending in _test.go that contains functions named TestXXX with signature func (t *testing.T). The test framework runs each such function; if the function calls a failure function such as t.Error or t.Fail, the test is considered to have failed.