Refactor remaining users of the ioutil package
Go 1.15 has deprecated the ioutil
package and made replacements
available in the io
or os
packages. While we have already migrated
most callsites away, one notable omission was ioutil.ReadDir()
as this
function doesn't have an exact replacement: the new os.ReadDir()
function does not stat all directory entries anymore.
This MR refactors remaining users of the deprecated function.