use proc_macro2::TokenStream as TokenStream2;
use quote::quote;
use syn::{Fields, ItemStruct, Path};
use crate::internals::{
attributes::{field, BoundType},
generics, serialize,
};
pub fn process(input: &ItemStruct, cratename: Path) -> syn::Result<TokenStream2> {
let name = &input.ident;
let generics = generics::without_defaults(&input.generics);
let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
let mut where_clause = generics::default_where(where_clause);
let mut body = TokenStream2::new();
let mut generics_output = serialize::GenericsOutput::new(&generics);
match &input.fields {
Fields::Named(fields) => {
for field in &fields.named {
let field_id = serialize::FieldId::Struct(field.ident.clone().unwrap());
process_field(field, field_id, &cratename, &mut generics_output, &mut body)?;
}
}
Fields::Unnamed(fields) => {
for (field_idx, field) in fields.unnamed.iter().enumerate() {
let field_id = serialize::FieldId::new_struct_unnamed(field_idx)?;
process_field(field, field_id, &cratename, &mut generics_output, &mut body)?;
}
}
Fields::Unit => {}
}
generics_output.extend(&mut where_clause, &cratename);
Ok(quote! {
#[automatically_derived]
impl #impl_generics #cratename::ser::BorshSerialize for #name #ty_generics #where_clause {
fn serialize<__W: #cratename::io::Write>(&self, writer: &mut __W) -> ::core::result::Result<(), #cratename::io::Error> {
#body
Ok(())
}
}
})
}
fn process_field(
field: &syn::Field,
field_id: serialize::FieldId,
cratename: &Path,
generics: &mut serialize::GenericsOutput,
body: &mut TokenStream2,
) -> syn::Result<()> {
let parsed = field::Attributes::parse(&field.attrs)?;
let needs_bounds_derive = parsed.needs_bounds_derive(BoundType::Serialize);
generics
.overrides
.extend(parsed.collect_bounds(BoundType::Serialize));
if !parsed.skip {
let delta = field_id.serialize_output(cratename, parsed.serialize_with);
body.extend(delta);
if needs_bounds_derive {
generics.serialize_visitor.visit_field(field);
}
}
Ok(())
}
#[cfg(test)]
mod tests {
use crate::internals::test_helpers::{
default_cratename, local_insta_assert_debug_snapshot, local_insta_assert_snapshot,
pretty_print_syn_str,
};
use super::*;
#[test]
fn simple_struct() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct A {
x: u64,
y: String,
}
})
.unwrap();
let actual = process(&item_struct, default_cratename()).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn simple_struct_with_custom_crate() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct A {
x: u64,
y: String,
}
})
.unwrap();
let crate_: Path = syn::parse2(quote! { reexporter::borsh }).unwrap();
let actual = process(&item_struct, crate_).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn simple_generics() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct A<K, V> {
x: HashMap<K, V>,
y: String,
}
})
.unwrap();
let actual = process(&item_struct, default_cratename()).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn simple_generic_tuple_struct() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct TupleA<T>(T, u32);
})
.unwrap();
let actual = process(&item_struct, default_cratename()).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn bound_generics() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct A<K: Key, V> where V: Value {
x: HashMap<K, V>,
y: String,
}
})
.unwrap();
let actual = process(&item_struct, default_cratename()).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn recursive_struct() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct CRecC {
a: String,
b: HashMap<String, CRecC>,
}
})
.unwrap();
let actual = process(&item_struct, default_cratename()).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn generic_tuple_struct_borsh_skip1() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct G<K, V, U> (
#[borsh(skip)]
HashMap<K, V>,
U,
);
})
.unwrap();
let actual = process(&item_struct, default_cratename()).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn generic_tuple_struct_borsh_skip2() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct G<K, V, U> (
HashMap<K, V>,
#[borsh(skip)]
U,
);
})
.unwrap();
let actual = process(&item_struct, default_cratename()).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn generic_named_fields_struct_borsh_skip() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct G<K, V, U> {
#[borsh(skip)]
x: HashMap<K, V>,
y: U,
}
})
.unwrap();
let actual = process(&item_struct, default_cratename()).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn generic_associated_type() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct Parametrized<T, V>
where
T: TraitName,
{
field: T::Associated,
another: V,
}
})
.unwrap();
let actual = process(&item_struct, default_cratename()).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn generic_serialize_bound() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct C<T: Debug, U> {
a: String,
#[borsh(bound(serialize =
"T: borsh::ser::BorshSerialize + PartialOrd,
U: borsh::ser::BorshSerialize"
))]
b: HashMap<T, U>,
}
})
.unwrap();
let actual = process(&item_struct, default_cratename()).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn override_generic_associated_type_wrong_derive() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct Parametrized<T, V> where T: TraitName {
#[borsh(bound(serialize =
"<T as TraitName>::Associated: borsh::ser::BorshSerialize"
))]
field: <T as TraitName>::Associated,
another: V,
}
})
.unwrap();
let actual = process(&item_struct, default_cratename()).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn check_serialize_with_attr() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct A<K: Ord, V> {
#[borsh(serialize_with = "third_party_impl::serialize_third_party")]
x: ThirdParty<K, V>,
y: u64,
}
})
.unwrap();
let actual = process(&item_struct, default_cratename()).unwrap();
local_insta_assert_snapshot!(pretty_print_syn_str(&actual).unwrap());
}
#[test]
fn check_serialize_with_skip_conflict() {
let item_struct: ItemStruct = syn::parse2(quote! {
struct A<K: Ord, V> {
#[borsh(skip,serialize_with = "third_party_impl::serialize_third_party")]
x: ThirdParty<K, V>,
y: u64,
}
})
.unwrap();
let actual = process(&item_struct, default_cratename());
let err = match actual {
Ok(..) => unreachable!("expecting error here"),
Err(err) => err,
};
local_insta_assert_debug_snapshot!(err);
}
}