Removing excessive dashes with OR regex

I'm trying to remove all excessive dashes from strings.

StateFileRegexDashes = regexp.MustCompile(--+?|^-+?|-+$)

The above regex seems to work for me on regex101, but not within my code.
I was thinking it could be because of the 'g|global modifier', but I assume that is solved by the 'All' part in ReplaceAllString()

Golang Playground: https://play.golang.org/p/ZR72gZEhZ_
Regex101: https://regex101.com/r/tUYHo1/1

Edit:
Problem was I was replacing everything with - dashes, where I actually wanted to remove prefixed and trailing dashes.

Instead of doing another regex, I'm just using strings.Trim() now.

var (
	StateFileRegex       = regexp.MustCompile(`[\/\?<>\\:\*\|":!\s.]`)
	StateFileRegexDashes = regexp.MustCompile(`--+`)
)

func hashBotStateFile(name string) string {
	lower := strings.ToLower(name)
	dashes := StateFileRegex.ReplaceAllString(lower, StateFileCharReplacer)
	singles := StateFileRegexDashes.ReplaceAllString(dashes, StateFileCharReplacer)
	trimmed := strings.Trim(singles, "-")
	return filepath.Join(StateFileFolder, fmt.Sprintf("%s.json", trimmed))
}

You need to remove the leading/trailing - symbols, and shrink those inside the string. You need to split the dashes regex into

StateFileRegexDashes = regexp.MustCompile(`--+`)
StateFileRegexDashesRemove = regexp.MustCompile(`^-+|-+$`)

And then use something like

func hashBotStateFile(name string) string {
	lower := strings.ToLower(name)
	dashes := StateFileRegex.ReplaceAllString(lower, StateFileCharReplacer)
	trimmed := StateFileRegexDashes.ReplaceAllString(dashes, StateFileCharReplacer)
	final := StateFileRegexDashesRemove.ReplaceAllString(trimmed, "")
	return filepath.Join(StateFileFolder, fmt.Sprintf("%s.json", final))
}

See the Go demo

Also, note that --+? at the end of the pattern will always match only 2 hyphens, you need to turn the lazy quantifiers into greedy ones.