env GO111MODULE=off

[short] skip

go test -coverpkg=all -covermode=atomic x
stdout ok[\s\S]+?coverage

[!race] stop

go test -coverpkg=all -race x
stdout ok[\s\S]+?coverage

-- x/x.go --
package x

import _ "sync/atomic"

func F() {}

-- x/x_test.go --
package x

import "testing"

func TestF(t *testing.T) { F() }