Keep it simple stupid. Given a geojson feature, and a zoom return all the tiles that have an intersection. The old one tried to determine the zoom for you this one skips that.
package main
import (
"github.com/paulmach/go.geojson"
"io/ioutil"
"fmt"
"github.com/murphy214/tile-cover"
m "github.com/murphy214/mercantile"
)
func main() {
bytevals,_ := ioutil.ReadFile("states.geojson")
fc, _ := geojson.UnmarshalFeatureCollection(bytevals)
feat := fc.Features[20]
tileids := tile_cover.TileCover(feat,10)
for _,i := range tileids {
fmt.Println(m.Tilestr(i))
}
}