Function findExpandableVars

pkg/workflow/shell.go:194–222

findExpandableVars returns all unique ${VAR_NAME} patterns in the string. It intentionally skips ${{ }} GitHub Actions expressions: those are evaluated by the GH Actions runner before the shell runs and must remain intact inside single-quoted strings — they should NOT be broken out as shell variable

(s string)

// by the GH Actions runner before the shell runs and must remain intact inside
// single-quoted strings — they should NOT be broken out as shell variables.
func findExpandableVars(s string) []string {
	var vars []string
	seen := make(map[string]struct {
	})
	for {
		start := strings.Index(s, "${")
		if start < 0 {
			break
		}
		// Skip GitHub Actions expressions (${{ ... }}): they start with ${{ and
		// must not be treated as shell variable references.
		if start+2 < len(s) && s[start+2] == '{' {
			s = s[start+3:]
			continue
		}
		end := strings.Index(s[start:], "}")
		if end < 0 {
			break
		}
		varRef := s[start : start+end+1]
		if !setutil.Contains(seen, varRef) {
			seen[varRef] = struct {
			}{}
			vars = append(vars, varRef)
		}
		s = s[start+end+1:]
	}
	return vars
}