Description
The way that the Go SDK handles optional strings is somewhat awkward, and while this ship may have sailed, @tasn asked me to provide some feedback here.
First of all, I totally understand that there's a need for a NullableString type of some kind. While idiomatic Go loves to use "zero values" including the empty string, other languages and APIs don't always work well with that, and so a string type that can also represent unset/JSON null is necessary.
But the implementation and use of NullableString in the Go SDK is awkward. Perhaps the most awkward aspect is that the helper function svix.NullableString a) takes a *string rather than a string, and b) returns not an openapi.NullableString but a *openapi.NullableString.
That means that the only way to create an openapi.NullableString from a static string literal in a single line, is the rather unwieldy *svix.NullableString(svix.String("mystring")).
The problem is compounded by the fact that openapi.NullableString is a private type, and as a result it is impossible to write 3rd-party code that manipulates it directly:
// This will not compile because the openapi package is internal.
func nullableString(s string) openapi.NullableString {
return *svix.NullableString(&s)
}What's particularly odd about the choice to return a pointer from svix.NullableString is that the data types that need nullable strings only ever want an openapi.NullableString, not a pointer to one, which leads to code like:
appIn := svix.ApplicationIn{
...
Uid: *svix.NullableString(svix.String("myuid"))
}Suggested alternative
I think a much more Go-friendly implementation here would be to make the type something like database/sql's NullString (https://pkg.go.dev/database/sql#NullString).
package types
type NullableString {
String string
Valid bool
}and then define your helper function as
package svix
func NullableString(s string) types.NullableString {
return types.NullableString{
String: s,
Valid: true,
}
}That creates a situation where the zero-valued types.NullableString is null, because the zero value of Valid is false:
type ApplicationIn struct {
Uid types.NullableString
}
app := ApplicationIn{}
fmt.Printf("%v\n", app.Uid.Valid) // Prints falseAnd constructing one to pass into a type is equally straightforward:
app := ApplicationIn{
Uid: NullableString("my-app-id"),
}
fmt.Printf("%v\n", app.Uid.Valid) // Prints trueHere's another example to play around with: https://go.dev/play/p/jYGq7qCCC11