need these flags

Makefile

@@ -1,6 +1,4 @@
-all:
-	@echo
-	@echo
+all: goimports vet
 
 clean:
 	rm -f go.*
@@ -10,6 +8,9 @@ redomod:
 	GO111MODULE= go mod init
 	GO111MODULE= go mod tidy
 
+test:
+	go test
+
 vet:
 	@GO111MODULE=off go vet
 	@echo this go binary package builds okay

go.mod

@@ -1,14 +1,14 @@
 module go.wit.com/dev/alexflint/arg
 
-go 1.24.1
-
 require (
 	github.com/alexflint/go-scalar v1.2.0
-	github.com/stretchr/testify v1.11.1
+	github.com/stretchr/testify v1.7.0
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
+	gopkg.in/yaml.v3 v3.0.0 // indirect
 )
+
+go 1.18

go.sum

@@ -1,13 +1,16 @@
 github.com/alexflint/go-scalar v1.2.0 h1:WR7JPKkeNpnYIOfHRa7ivM21aWAdHD0gEWHCx+WQBRw=
 github.com/alexflint/go-scalar v1.2.0/go.mod h1:LoFvNMqS1CPrMVltza4LvnGKhaSpc3oyLEBUZVhhS2o=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
-github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
-github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
-gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0 h1:hjy8E9ON/egN1tAYqKb61G10WtihqetD4sz2H+8nIeA=
+gopkg.in/yaml.v3 v3.0.0/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

parse.go

@@ -98,6 +98,7 @@ func Register(dest ...interface{}) {
 
 // MustParse processes command line arguments and exits upon failure
 func MustParse(dest ...interface{}) *Parser {
+	register = append(register, dest...)
 	return mustParse(Config{Exit: mustParseExit, Out: mustParseOut}, register...)
 }
 
@@ -123,8 +124,24 @@ func Parse(dest ...interface{}) error {
 	return p.Parse(flags())
 }
 
+// pass in a "pretend" os.Args. Used for bash autocomplete
+func ParseFlags(flags []string, dest ...interface{}) (*Parser, error) {
+	p, err := NewParser(Config{}, dest...)
+	if err != nil {
+		return p, err
+	}
+	overrideFlags = append(overrideFlags, flags...)
+	err = p.Parse(flags)
+	return p, err
+}
+
+var overrideFlags []string
+
 // flags gets all command line arguments other than the first (program name)
 func flags() []string {
+	if len(overrideFlags) > 0 {
+		return overrideFlags
+	}
 	if len(os.Args) == 0 { // os.Args could be empty
 		return nil
 	}