Fix parsing empty oneofs

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bomboni"
-version = "0.1.28"
+version = "0.1.30"
 authors = ["Tin Rabzelj <tin@flinect.com>"]
 description = "Utility Library for Rust"
 repository = "https://github.com/tinrab/bomboni"
@@ -38,9 +38,9 @@ tokio = ["bomboni_common/tokio"]
 tonic = ["bomboni_proto/tonic", "bomboni_request/tonic"]
 
 [dependencies]
-bomboni_common = { path = "bomboni_common", version = "0.1.28" }
+bomboni_common = { path = "bomboni_common", version = "0.1.30" }
 
-bomboni_prost = { path = "bomboni_prost", version = "0.1.28", optional = true }
-bomboni_proto = { path = "bomboni_proto", version = "0.1.28", optional = true }
-bomboni_request = { path = "bomboni_request", version = "0.1.28", optional = true }
-bomboni_template = { path = "bomboni_template", version = "0.1.28", optional = true }
+bomboni_prost = { path = "bomboni_prost", version = "0.1.30", optional = true }
+bomboni_proto = { path = "bomboni_proto", version = "0.1.30", optional = true }
+bomboni_request = { path = "bomboni_request", version = "0.1.30", optional = true }
+bomboni_template = { path = "bomboni_template", version = "0.1.30", optional = true }

bomboni_common/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bomboni_common"
-version = "0.1.28"
+version = "0.1.30"
 authors = ["Tin Rabzelj <tin@flinect.com>"]
 description = "Common things for Bomboni library."
 repository = "https://github.com/tinrab/bomboni"

bomboni_prost/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bomboni_prost"
-version = "0.1.28"
+version = "0.1.30"
 authors = ["Tin Rabzelj <tin@flinect.com>"]
 description = "Utilities for working with prost. Part of Bomboni library."
 repository = "https://github.com/tinrab/bomboni"

bomboni_proto/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bomboni_proto"
-version = "0.1.28"
+version = "0.1.30"
 authors = ["Tin Rabzelj <tin@flinect.com>"]
 description = "Utilities for working with Protobuf/gRPC. Part of Bomboni library."
 repository = "https://github.com/tinrab/bomboni"
@@ -36,5 +36,5 @@ serde_json = { version = "1.0.108", optional = true }
 serde_json = "1.0.108"
 
 [build-dependencies]
-bomboni_prost = { path = "../bomboni_prost", version = "0.1.28" }
+bomboni_prost = { path = "../bomboni_prost", version = "0.1.30" }
 prost-build = "0.12.3"

bomboni_request/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bomboni_request"
-version = "0.1.28"
+version = "0.1.30"
 authors = ["Tin Rabzelj <tin@flinect.com>"]
 description = "Utilities for working with API requests. Part of Bomboni library."
 repository = "https://github.com/tinrab/bomboni"
@@ -19,8 +19,8 @@ testing = []
 tonic = ["bomboni_proto/tonic", "dep:tonic"]
 
 [dependencies]
-bomboni_common = { path = "../bomboni_common", version = "0.1.28" }
-bomboni_proto = { path = "../bomboni_proto", version = "0.1.28" }
+bomboni_common = { path = "../bomboni_common", version = "0.1.30" }
+bomboni_proto = { path = "../bomboni_proto", version = "0.1.30" }
 thiserror = "1.0.50"
 itertools = "0.12.0"
 time = { version = "0.3.30", features = ["formatting", "parsing"] }
@@ -35,4 +35,4 @@ rand = "0.8.5"
 regex = "1.10.2"
 
 tonic = { version = "0.10.2", optional = true }
-bomboni_request_derive = { path = "../bomboni_request_derive", version = "0.1.28", optional = true }
+bomboni_request_derive = { path = "../bomboni_request_derive", version = "0.1.30", optional = true }

bomboni_request/src/parse/mod.rs

@@ -1042,4 +1042,71 @@ mod tests {
             }
         );
     }
+
+    #[test]
+    fn parse_oneof() {
+        #[derive(Debug, Clone, PartialEq)]
+        enum Item {
+            String(String),
+            Data(Data),
+            Null(()),
+            Empty,
+            Dropped(i32),
+        }
+
+        impl Item {
+            pub fn get_variant_name(&self) -> &'static str {
+                match self {
+                    Self::String(_) => "string",
+                    Self::Data(_) => "data",
+                    Self::Null(_) => "null",
+                    Self::Empty => "empty",
+                    Self::Dropped(_) => "dropped",
+                }
+            }
+        }
+
+        #[derive(Debug, Clone, Default, PartialEq)]
+        struct Data {
+            value: i32,
+        }
+
+        #[derive(Debug, Clone, PartialEq, Parse)]
+        #[parse(source= Item, write)]
+        enum ParsedItem {
+            String(String),
+            Data(ParsedData),
+            Null(()),
+            #[parse(source_empty)]
+            Empty,
+            Dropped,
+        }
+
+        #[derive(Debug, Clone, Default, PartialEq, Parse)]
+        #[parse(source= Data, write)]
+        struct ParsedData {
+            value: i32,
+        }
+
+        assert_eq!(
+            ParsedItem::parse(Item::String("abc".into())).unwrap(),
+            ParsedItem::String("abc".into())
+        );
+        assert_eq!(
+            Item::from(ParsedItem::String("abc".into())),
+            Item::String("abc".into())
+        );
+
+        assert_eq!(
+            ParsedItem::parse(Item::Data(Data { value: 42 })).unwrap(),
+            ParsedItem::Data(ParsedData { value: 42 })
+        );
+        assert_eq!(
+            Item::from(ParsedItem::Data(ParsedData { value: 42 })),
+            Item::Data(Data { value: 42 })
+        );
+
+        assert_eq!(ParsedItem::parse(Item::Empty).unwrap(), ParsedItem::Empty);
+        assert_eq!(Item::from(ParsedItem::Empty), Item::Empty);
+    }
 }

bomboni_request_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bomboni_request_derive"
-version = "0.1.28"
+version = "0.1.30"
 authors = ["Tin Rabzelj <tin@flinect.com>"]
 description = "Provides derive implementations for Bomboni library."
 repository = "https://github.com/tinrab/bomboni"

bomboni_request_derive/src/parse/message/mod.rs

@@ -1,9 +1,6 @@
-use darling::FromMeta;
-use proc_macro2::{Ident, Literal, TokenStream};
-use quote::{quote, ToTokens};
+use proc_macro2::TokenStream;
 
-use crate::parse::{ParseOptions, ParseTaggedUnion, ParseVariant};
-use crate::utility::{get_proto_type_info, ProtoTypeInfo};
+use crate::parse::ParseOptions;
 
 use super::ParseField;
 

bomboni_request_derive/src/parse/message/write.rs

@@ -1,9 +1,8 @@
 use darling::FromMeta;
-use itertools::Itertools;
-use proc_macro2::{Ident, Literal, TokenStream};
+use proc_macro2::{Ident, TokenStream};
 use quote::{quote, ToTokens};
 
-use crate::parse::{DeriveOptions, ParseField, ParseOptions};
+use crate::parse::{ParseField, ParseOptions};
 use crate::utility::{get_proto_type_info, ProtoTypeInfo};
 
 pub fn expand(options: &ParseOptions, fields: &[ParseField]) -> TokenStream {

bomboni_request_derive/src/parse/mod.rs

@@ -99,6 +99,9 @@ pub struct ParseVariant {
     /// True if the source variant should be dereferenced from a `Box` type.
     #[darling(default)]
     pub source_box: bool,
+    /// True if the source is an empty unit variant.
+    #[darling(default)]
+    pub source_empty: bool,
     /// Parses enum value from `i32`.
     #[darling(default)]
     pub enumeration: bool,

bomboni_request_derive/src/parse/oneof/mod.rs

@@ -1,17 +1,14 @@
-use darling::FromMeta;
-use proc_macro2::{Ident, Literal, TokenStream};
-use quote::{quote, ToTokens};
+use proc_macro2::TokenStream;
 
-use crate::parse::{ParseOptions, ParseTaggedUnion, ParseVariant};
-use crate::utility::{get_proto_type_info, ProtoTypeInfo};
+use crate::parse::{ParseOptions, ParseVariant};
 
 mod parse;
 mod write;
 
 pub fn expand(options: &ParseOptions, variants: &[ParseVariant]) -> syn::Result<TokenStream> {
     let mut result = parse::expand(options, variants)?;
     if options.write {
-        result.extend(write::expand(options, variants)?);
+        result.extend(write::expand(options, variants));
     }
     Ok(result)
 }

bomboni_request_derive/src/parse/oneof/parse.rs

@@ -30,14 +30,30 @@ fn expand_parse(options: &ParseOptions, variants: &[ParseVariant]) -> syn::Resul
         };
         let target_variant_ident = &variant.ident;
 
-        let parse_variant = expand_parse_variant(variant)?;
-        parse_variants.extend(quote! {
-            #source::#source_variant_ident(source) => {
-                #ident::#target_variant_ident({
-                    #parse_variant
-                })
-            }
-        });
+        if variant.fields.is_empty() {
+            parse_variants.extend(if variant.source_empty {
+                quote! {
+                    #source::#source_variant_ident => {
+                        #ident::#target_variant_ident
+                    }
+                }
+            } else {
+                quote! {
+                    #source::#source_variant_ident(_) => {
+                        #ident::#target_variant_ident
+                    }
+                }
+            });
+        } else {
+            let parse_variant = expand_parse_variant(variant)?;
+            parse_variants.extend(quote! {
+                #source::#source_variant_ident(source) => {
+                    #ident::#target_variant_ident({
+                        #parse_variant
+                    })
+                }
+            });
+        }
     }
 
     Ok(quote! {
@@ -82,9 +98,18 @@ fn expand_tagged_union(
         let target_variant_ident = &variant.ident;
 
         if variant.fields.is_empty() {
-            // Handle unit variants
-            parse_variants.extend(quote! {
-                #oneof_ident::#source_variant_ident(_) => #ident::#target_variant_ident,
+            parse_variants.extend(if variant.source_empty {
+                quote! {
+                    #oneof_ident::#source_variant_ident => {
+                        #ident::#target_variant_ident
+                    }
+                }
+            } else {
+                quote! {
+                    #oneof_ident::#source_variant_ident(_) => {
+                        #ident::#target_variant_ident
+                    }
+                }
             });
         } else {
             let parse_variant = expand_parse_variant(variant)?;
@@ -119,6 +144,19 @@ fn expand_tagged_union(
 }
 
 fn expand_parse_variant(variant: &ParseVariant) -> syn::Result<TokenStream> {
+    if (variant.with.is_some() || variant.parse_with.is_some()) && variant.regex.is_some() {
+        return Err(syn::Error::new_spanned(
+            &variant.ident,
+            "some of these options cannot be used alongside `with`",
+        ));
+    }
+    if variant.with.is_some() && (variant.parse_with.is_some() || variant.write_with.is_some()) {
+        return Err(syn::Error::new_spanned(
+            &variant.ident,
+            "custom `parse_with` and `write_with` functions cannot be used alongside `with`",
+        ));
+    }
+
     if variant.fields.len() != 1 {
         return Err(syn::Error::new_spanned(
             &variant.ident,
@@ -135,24 +173,12 @@ fn expand_parse_variant(variant: &ParseVariant) -> syn::Result<TokenStream> {
         ..
     } = get_proto_type_info(variant_type);
 
-    if (variant.with.is_some() || variant.parse_with.is_some()) && variant.regex.is_some() {
-        return Err(syn::Error::new_spanned(
-            &variant.ident,
-            "some of these options cannot be used alongside `with`",
-        ));
-    }
     if variant.regex.is_some() && !is_string {
         return Err(syn::Error::new_spanned(
             &variant.ident,
             "regex can only be used with string variants",
         ));
     }
-    if variant.with.is_some() && (variant.parse_with.is_some() || variant.write_with.is_some()) {
-        return Err(syn::Error::new_spanned(
-            &variant.ident,
-            "custom `parse_with` and `write_with` functions cannot be used alongside `with`",
-        ));
-    }
 
     let parse_source = if variant.with.is_some() || variant.parse_with.is_some() {
         let parse_with = if let Some(with) = variant.with.as_ref() {

bomboni_request_derive/src/parse/oneof/write.rs

@@ -1,16 +1,16 @@
 use darling::FromMeta;
-use proc_macro2::{Ident, Literal, TokenStream};
+use proc_macro2::{Ident, TokenStream};
 use quote::{quote, ToTokens};
 
 use crate::parse::{ParseOptions, ParseTaggedUnion, ParseVariant};
 use crate::utility::{get_proto_type_info, ProtoTypeInfo};
 
-pub fn expand(options: &ParseOptions, variants: &[ParseVariant]) -> syn::Result<TokenStream> {
-    Ok(if let Some(tagged_union) = options.tagged_union.as_ref() {
+pub fn expand(options: &ParseOptions, variants: &[ParseVariant]) -> TokenStream {
+    if let Some(tagged_union) = options.tagged_union.as_ref() {
         expand_write_tagged_union(options, variants, tagged_union)
     } else {
         expand_write(options, variants)
-    })
+    }
 }
 
 fn expand_write(options: &ParseOptions, variants: &[ParseVariant]) -> TokenStream {
@@ -32,9 +32,18 @@ fn expand_write(options: &ParseOptions, variants: &[ParseVariant]) -> TokenStrea
         let target_variant_ident = &variant.ident;
 
         if variant.fields.is_empty() {
-            // Handle unit variants
-            write_variants.extend(quote! {
-                #ident::#target_variant_ident => #source::#source_variant_ident(Default::default()),
+            write_variants.extend(if variant.source_empty {
+                quote! {
+                    #ident::#target_variant_ident => {
+                        #source::#source_variant_ident
+                    }
+                }
+            } else {
+                quote! {
+                    #ident::#target_variant_ident => {
+                        #source::#source_variant_ident(Default::default())
+                    }
+                }
             });
         } else {
             let write_variant = expand_write_variant(variant);
@@ -84,9 +93,18 @@ fn expand_write_tagged_union(
         let target_variant_ident = &variant.ident;
 
         if variant.fields.is_empty() {
-            // Handle unit variants
-            write_variants.extend(quote! {
-                #ident::#target_variant_ident => #oneof_ident::#source_variant_ident(Default::default()),
+            write_variants.extend(if variant.source_empty {
+                quote! {
+                    #ident::#target_variant_ident => {
+                        #oneof_ident::#source_variant_ident
+                    }
+                }
+            } else {
+                quote! {
+                    #ident::#target_variant_ident => {
+                        #oneof_ident::#source_variant_ident(Default::default())
+                    }
+                }
             });
         } else {
             let write_variant = expand_write_variant(variant);