use serde::ser::{
self, Serialize, SerializeMap, SerializeSeq, SerializeStruct, SerializeStructVariant,
SerializeTuple, SerializeTupleStruct, SerializeTupleVariant,
};
use snafu::Snafu;
use std::fmt::Display;
#[derive(Debug, Snafu)]
pub enum Error {
#[snafu(display("Failed to serialize object: {}", msg))]
SerializationError { msg: String },
}
impl serde::ser::Error for Error {
fn custom<T>(msg: T) -> Self
where
T: Display,
{
Self::SerializationError {
msg: msg.to_string(),
}
}
}
pub struct Serializer {
args: Vec<String>,
boolean_type: BooleanType,
}
pub enum BooleanType {
TrueFalse,
OnOff,
}
impl Serializer {
pub fn new(boolean_type: BooleanType) -> Self {
Self {
args: vec![],
boolean_type,
}
}
pub fn into_args<T>(mut self, value: &T) -> Result<Vec<String>, Error>
where
T: Serialize,
{
value.serialize(&mut self)?;
Ok(self.args)
}
}
pub fn to_args<T>(value: &T) -> Result<Vec<String>, Error>
where
T: Serialize,
{
Serializer::new(BooleanType::TrueFalse).into_args(value)
}
impl<'a> ser::Serializer for &'a mut Serializer {
type Ok = ();
type Error = Error;
type SerializeSeq = Self;
type SerializeTuple = Self;
type SerializeTupleStruct = Self;
type SerializeTupleVariant = Self;
type SerializeMap = Self;
type SerializeStruct = Self;
type SerializeStructVariant = Self;
fn serialize_bool(self, v: bool) -> Result<Self::Ok, Self::Error> {
self.args.push(
match self.boolean_type {
BooleanType::TrueFalse => {
if v {
"true"
} else {
"false"
}
}
BooleanType::OnOff => {
if v {
"on"
} else {
"off"
}
}
}
.into(),
);
Ok(())
}
fn serialize_i8(self, v: i8) -> Result<Self::Ok, Self::Error> {
self.serialize_i64(i64::from(v))
}
fn serialize_i16(self, v: i16) -> Result<Self::Ok, Self::Error> {
self.serialize_i64(i64::from(v))
}
fn serialize_i32(self, v: i32) -> Result<Self::Ok, Self::Error> {
self.serialize_i64(i64::from(v))
}
fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error> {
self.args.push(v.to_string());
Ok(())
}
fn serialize_u8(self, v: u8) -> Result<Self::Ok, Self::Error> {
self.serialize_u64(u64::from(v))
}
fn serialize_u16(self, v: u16) -> Result<Self::Ok, Self::Error> {
self.serialize_u64(u64::from(v))
}
fn serialize_u32(self, v: u32) -> Result<Self::Ok, Self::Error> {
self.serialize_u64(u64::from(v))
}
fn serialize_u64(self, v: u64) -> Result<Self::Ok, Self::Error> {
self.args.push(v.to_string());
Ok(())
}
fn serialize_f32(self, v: f32) -> Result<Self::Ok, Self::Error> {
self.serialize_f64(f64::from(v))
}
fn serialize_f64(self, v: f64) -> Result<Self::Ok, Self::Error> {
self.args.push(v.to_string());
Ok(())
}
fn serialize_char(self, v: char) -> Result<Self::Ok, Self::Error> {
self.serialize_str(&v.to_string())
}
fn serialize_str(self, v: &str) -> Result<Self::Ok, Self::Error> {
self.args.push(v.into());
Ok(())
}
fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
unimplemented!()
}
fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
self.args.pop();
self.serialize_unit()
}
fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
where
T: Serialize,
{
value.serialize(self)
}
fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
Ok(())
}
fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
self.serialize_unit()
}
fn serialize_unit_variant(
self,
_name: &'static str,
_variant_index: u32,
variant: &'static str,
) -> Result<Self::Ok, Self::Error> {
self.serialize_str(variant)
}
fn serialize_newtype_struct<T: ?Sized>(
self,
_name: &'static str,
value: &T,
) -> Result<Self::Ok, Self::Error>
where
T: Serialize,
{
value.serialize(self)
}
fn serialize_newtype_variant<T: ?Sized>(
self,
_name: &'static str,
_variant_index: u32,
variant: &'static str,
value: &T,
) -> Result<Self::Ok, Self::Error>
where
T: Serialize,
{
variant.serialize(&mut *self)?;
value.serialize(&mut *self)?;
Ok(())
}
fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
self.args.pop();
Ok(self)
}
fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple, Self::Error> {
self.serialize_seq(Some(len))
}
fn serialize_tuple_struct(
self,
_name: &'static str,
len: usize,
) -> Result<Self::SerializeTupleStruct, Self::Error> {
self.serialize_seq(Some(len))
}
fn serialize_tuple_variant(
self,
_name: &'static str,
_variant_index: u32,
variant: &'static str,
_len: usize,
) -> Result<Self::SerializeTupleVariant, Self::Error> {
variant.serialize(&mut *self)?;
Ok(self)
}
fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
Ok(self)
}
fn serialize_struct(
self,
_name: &'static str,
len: usize,
) -> Result<Self::SerializeStruct, Self::Error> {
self.serialize_map(Some(len))
}
fn serialize_struct_variant(
self,
_name: &'static str,
_variant_index: u32,
variant: &'static str,
_len: usize,
) -> Result<Self::SerializeStructVariant, Self::Error> {
variant.serialize(&mut *self)?;
Ok(self)
}
fn collect_str<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
where
T: Display,
{
unimplemented!()
}
}
impl<'a> SerializeSeq for &'a mut Serializer {
type Ok = ();
type Error = Error;
fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
where
T: Serialize,
{
value.serialize(&mut **self)
}
fn end(self) -> Result<Self::Ok, Self::Error> {
Ok(())
}
}
impl<'a> SerializeTuple for &'a mut Serializer {
type Ok = ();
type Error = Error;
fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
where
T: Serialize,
{
value.serialize(&mut **self)
}
fn end(self) -> Result<Self::Ok, Self::Error> {
Ok(())
}
}
impl<'a> SerializeTupleStruct for &'a mut Serializer {
type Ok = ();
type Error = Error;
fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
where
T: Serialize,
{
value.serialize(&mut **self)
}
fn end(self) -> Result<Self::Ok, Self::Error> {
Ok(())
}
}
impl<'a> SerializeTupleVariant for &'a mut Serializer {
type Ok = ();
type Error = Error;
fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
where
T: Serialize,
{
value.serialize(&mut **self)
}
fn end(self) -> Result<Self::Ok, Self::Error> {
Ok(())
}
}
impl<'a> SerializeMap for &'a mut Serializer {
type Ok = ();
type Error = Error;
fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
where
T: Serialize,
{
key.serialize(&mut **self)
}
fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
where
T: Serialize,
{
value.serialize(&mut **self)
}
fn end(self) -> Result<Self::Ok, Self::Error> {
Ok(())
}
}
impl<'a> SerializeStruct for &'a mut Serializer {
type Ok = ();
type Error = Error;
fn serialize_field<T: ?Sized>(
&mut self,
key: &'static str,
value: &T,
) -> Result<(), Self::Error>
where
T: Serialize,
{
key.serialize(&mut **self)?;
value.serialize(&mut **self)
}
fn end(self) -> Result<Self::Ok, Self::Error> {
Ok(())
}
}
impl<'a> SerializeStructVariant for &'a mut Serializer {
type Ok = ();
type Error = Error;
fn serialize_field<T: ?Sized>(
&mut self,
key: &'static str,
value: &T,
) -> Result<(), Self::Error>
where
T: Serialize,
{
key.serialize(&mut **self)?;
value.serialize(&mut **self)
}
fn end(self) -> Result<Self::Ok, Self::Error> {
Ok(())
}
}
#[cfg(test)]
mod tests {
use super::*;
use maplit::hashmap;
use serde::Serialize;
use std::collections::HashMap;
#[test]
fn test_simple_struct() {
#[derive(Serialize)]
struct Test {
signed_int: i32,
unsigned_int: u32,
string: String,
character: char,
}
let options = to_args(&Test {
signed_int: -10,
unsigned_int: 10,
string: String::from("Hello World"),
character: 'X',
})
.unwrap();
let expected: Vec<String> = vec![
"signed_int".into(),
"-10".into(),
"unsigned_int".into(),
"10".into(),
"string".into(),
"Hello World".into(),
"character".into(),
"X".into(),
];
assert_eq!(options, expected);
}
#[test]
fn test_nested_list() {
#[derive(Serialize)]
struct Test {
example: i32,
opts: Vec<String>,
}
let options = to_args(&Test {
example: 1,
opts: vec!["a".into(), "b".into(), "c".into()],
})
.unwrap();
let expected: Vec<String> = vec![
"example".into(),
"1".into(),
"a".into(),
"b".into(),
"c".into(),
];
assert_eq!(options, expected);
}
#[test]
fn test_nested_map() {
#[derive(Serialize)]
struct Test {
example: i32,
fields: HashMap<String, i32>,
}
let options = to_args(&Test {
example: 1,
fields: hashmap! {
"a".into() => 1,
"b".into() => 2,
},
})
.unwrap();
let expected: Vec<String> = vec![
"example".into(),
"1".into(),
"fields".into(),
"a".into(),
"1".into(),
"b".into(),
"2".into(),
];
assert_eq!(options, expected);
}
#[test]
fn test_boolean_modes() {
#[derive(Serialize)]
struct Test {
#[serde(rename = "my-feature")]
feature: bool,
}
let options = Serializer::new(BooleanType::OnOff)
.into_args(&Test { feature: true })
.unwrap();
let expected: Vec<String> = vec!["my-feature".into(), "on".into()];
assert_eq!(options, expected);
}
#[test]
fn test_optional_field() {
#[derive(Serialize)]
struct Test {
name: Option<String>,
}
let options = to_args(&Test {
name: Some("Alice".into()),
})
.unwrap();
let expected: Vec<String> = vec!["name".into(), "Alice".into()];
assert_eq!(options, expected);
let options = to_args(&Test { name: None }).unwrap();
let expected: Vec<String> = vec![];
assert_eq!(options, expected);
}
}