Add source_try_from

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bomboni"
-version = "0.1.30"
+version = "0.1.31"
 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 = "0.1.30" }
+bomboni_common = { path = "bomboni_common", version = "0.1.31" }
 
-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_prost = { path = "bomboni_prost", version = "0.1.31", optional = true }
+bomboni_proto = { path = "bomboni_proto", version = "0.1.31", optional = true }
+bomboni_request = { path = "bomboni_request", version = "0.1.31", optional = true }
+bomboni_template = { path = "bomboni_template", version = "0.1.31", optional = true }

bomboni_common/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bomboni_common"
-version = "0.1.30"
+version = "0.1.31"
 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 = "0.1.30"
+version = "0.1.31"
 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 = "0.1.30"
+version = "0.1.31"
 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 = "0.1.30" }
+bomboni_prost = { path = "../bomboni_prost", version = "0.1.31" }
 prost-build = "0.12.3"

bomboni_request/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bomboni_request"
-version = "0.1.30"
+version = "0.1.31"
 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 = "0.1.30" }
-bomboni_proto = { path = "../bomboni_proto", version = "0.1.30" }
+bomboni_common = { path = "../bomboni_common", version = "0.1.31" }
+bomboni_proto = { path = "../bomboni_proto", version = "0.1.31" }
 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 = "0.1.30", optional = true }
+bomboni_request_derive = { path = "../bomboni_request_derive", version = "0.1.31", optional = true }

bomboni_request/src/error.rs

@@ -77,6 +77,8 @@ pub enum CommonError {
     UnknownOneofVariant,
     #[error("invalid numeric value")]
     InvalidNumericValue,
+    #[error("failed to convert value")]
+    FailedConvertValue,
     #[error("out of range")]
     NumericOutOfRange,
     #[error("duplicate value")]

bomboni_request/src/parse/mod.rs

@@ -115,7 +115,7 @@ mod tests {
         struct ParsedItem {
             #[parse(source_name = "string")]
             s: String,
-            #[parse(source_option, source_name = "optional_string")]
+            #[parse(source_name = "optional_string")]
             opt_s: Option<String>,
             required_string: String,
             #[parse(source_option)]
@@ -1059,7 +1059,7 @@ mod tests {
                 match self {
                     Self::String(_) => "string",
                     Self::Data(_) => "data",
-                    Self::Null(_) => "null",
+                    Self::Null(()) => "null",
                     Self::Empty => "empty",
                     Self::Dropped(_) => "dropped",
                 }
@@ -1109,4 +1109,76 @@ mod tests {
         assert_eq!(ParsedItem::parse(Item::Empty).unwrap(), ParsedItem::Empty);
         assert_eq!(Item::from(ParsedItem::Empty), Item::Empty);
     }
+
+    #[test]
+    fn source_convert() {
+        #[derive(Debug, Clone, PartialEq, Default)]
+        struct Item {
+            casted_value: u32,
+            optional_casted: Option<u32>,
+        }
+
+        #[derive(Debug, Clone, PartialEq, Default, Parse)]
+        #[parse(source = Item, write)]
+        struct ParsedItem {
+            #[parse(source_try_from = u32)]
+            casted_value: usize,
+            #[parse(source_try_from = u32)]
+            optional_casted: Option<usize>,
+        }
+
+        #[derive(Debug, Clone, PartialEq)]
+        enum Union {
+            A(u32),
+            B(Option<u32>),
+        }
+
+        impl Union {
+            pub fn get_variant_name(&self) -> &'static str {
+                match self {
+                    Self::A(_) => "a",
+                    Self::B(_) => "b",
+                }
+            }
+        }
+
+        #[derive(Debug, Clone, PartialEq, Parse)]
+        #[parse(source = Union, write)]
+        enum ParsedUnion {
+            #[parse(source_try_from = u32)]
+            A(usize),
+            #[parse(source_try_from = u32)]
+            B(Option<usize>),
+        }
+
+        assert_eq!(
+            ParsedItem::parse(Item {
+                casted_value: 42,
+                optional_casted: Some(42),
+            })
+            .unwrap(),
+            ParsedItem {
+                casted_value: 42,
+                optional_casted: Some(42),
+            }
+        );
+        assert_eq!(
+            Item::from(ParsedItem {
+                casted_value: 42,
+                optional_casted: Some(42),
+            }),
+            Item {
+                casted_value: 42,
+                optional_casted: Some(42),
+            }
+        );
+
+        assert_eq!(
+            ParsedUnion::parse(Union::A(42)).unwrap(),
+            ParsedUnion::A(42)
+        );
+        assert_eq!(Union::from(ParsedUnion::A(42)), Union::A(42));
+        assert_eq!(Union::from(ParsedUnion::B(Some(42))), Union::B(Some(42)));
+        assert_eq!(Union::from(ParsedUnion::B(None)), Union::B(None));
+    }
 }

bomboni_request_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bomboni_request_derive"
-version = "0.1.30"
+version = "0.1.31"
 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/parse.rs

@@ -129,8 +129,14 @@ fn expand_parse_field(field: &ParseField) -> syn::Result<TokenStream> {
             "custom `parse_with` and `write_with` functions cannot be used alongside `with`",
         ));
     }
+    if field.wrapper && field.source_try_from.is_some() {
+        return Err(syn::Error::new_spanned(
+            &field.ident,
+            "wrapper fields cannot be casted",
+        ));
+    }
 
-    let parse_source = if field.with.is_some() || field.parse_with.is_some() {
+    let mut parse_source = if field.with.is_some() || field.parse_with.is_some() {
         let parse_with = if let Some(with) = field.with.as_ref() {
             quote! {
                 #with::parse
@@ -288,6 +294,13 @@ fn expand_parse_field(field: &ParseField) -> syn::Result<TokenStream> {
         quote!()
     };
 
+    if field.source_try_from.is_some() {
+        parse_source.extend(quote! {
+            let target = target.try_into()
+                .map_err(|_| RequestError::field(#field_name, CommonError::FailedConvertValue))?;
+        });
+    }
+
     let mut parse = quote! {
         let target = source.#source_ident;
     };
@@ -320,6 +333,7 @@ fn expand_parse_field(field: &ParseField) -> syn::Result<TokenStream> {
 
     // Source field for nested messages is always wrapped in `Option`
     let source_option = field.source_option
+        || is_option
         || (is_nested
             && (field.with.is_none() && field.parse_with.is_none())
             && !is_vec
@@ -423,7 +437,12 @@ fn expand_parse_field(field: &ParseField) -> syn::Result<TokenStream> {
 }
 
 fn expand_parse_resource_field(field: &ParseField) -> syn::Result<TokenStream> {
-    if field.source_option || field.enumeration || field.oneof || field.regex.is_some() {
+    if field.source_option
+        || field.enumeration
+        || field.oneof
+        || field.regex.is_some()
+        || field.source_try_from.is_some()
+    {
         return Err(syn::Error::new_spanned(
             &field.ident,
             "some of these options cannot be used alongside `resource`",

bomboni_request_derive/src/parse/message/write.rs

@@ -54,7 +54,7 @@ fn expand_write_field(field: &ParseField) -> TokenStream {
         ..
     } = get_proto_type_info(field_type);
 
-    let write_target = if field.with.is_some() || field.write_with.is_some() {
+    let mut write_target = if field.with.is_some() || field.write_with.is_some() {
         let write_with = if let Some(with) = field.with.as_ref() {
             quote! {
                 #with::write
@@ -127,6 +127,14 @@ fn expand_write_field(field: &ParseField) -> TokenStream {
         quote!()
     };
 
+    if let Some(source_try_from) = field.source_try_from.as_ref() {
+        let err_literal = format!("failed to convert `{source_ident}` to `{source_try_from}`");
+        write_target.extend(quote! {
+            let source: #source_try_from = source.try_into()
+                .expect(#err_literal);
+        });
+    }
+
     let mut write = quote! {
         let source = value.#target_ident;
     };
@@ -138,6 +146,7 @@ fn expand_write_field(field: &ParseField) -> TokenStream {
     };
 
     let source_option = field.source_option
+        || is_option
         || (is_nested
             && (field.with.is_none() && field.parse_with.is_none())
             && !is_vec

bomboni_request_derive/src/parse/mod.rs

@@ -49,6 +49,9 @@ pub struct ParseField {
     /// True if the source field should be dereferenced from a `Box` type.
     #[darling(default)]
     pub source_box: bool,
+    /// Type used to convert from and into the target type.
+    #[darling(default)]
+    pub source_try_from: Option<Ident>,
     /// Parses enum value from `i32`.
     #[darling(default)]
     pub enumeration: bool,
@@ -102,6 +105,9 @@ pub struct ParseVariant {
     /// True if the source is an empty unit variant.
     #[darling(default)]
     pub source_empty: bool,
+    /// Type used to convert from and into the target type.
+    #[darling(default)]
+    pub source_try_from: Option<Ident>,
     /// Parses enum value from `i32`.
     #[darling(default)]
     pub enumeration: bool,

bomboni_request_derive/src/parse/oneof/parse.rs

@@ -156,6 +156,12 @@ fn expand_parse_variant(variant: &ParseVariant) -> syn::Result<TokenStream> {
             "custom `parse_with` and `write_with` functions cannot be used alongside `with`",
         ));
     }
+    if variant.wrapper && variant.source_try_from.is_some() {
+        return Err(syn::Error::new_spanned(
+            &variant.ident,
+            "wrapper variants cannot be casted",
+        ));
+    }
 
     if variant.fields.len() != 1 {
         return Err(syn::Error::new_spanned(
@@ -180,7 +186,7 @@ fn expand_parse_variant(variant: &ParseVariant) -> syn::Result<TokenStream> {
         ));
     }
 
-    let parse_source = if variant.with.is_some() || variant.parse_with.is_some() {
+    let mut parse_source = if variant.with.is_some() || variant.parse_with.is_some() {
         let parse_with = if let Some(with) = variant.with.as_ref() {
             quote! {
                 #with::parse
@@ -235,6 +241,13 @@ fn expand_parse_variant(variant: &ParseVariant) -> syn::Result<TokenStream> {
         quote!()
     };
 
+    if variant.source_try_from.is_some() {
+        parse_source.extend(quote! {
+            let target = target.try_into()
+                .map_err(|_| RequestError::field(variant_name, CommonError::FailedConvertValue))?;
+        });
+    }
+
     let mut parse = quote! {
         let target = source;
     };
@@ -266,8 +279,10 @@ fn expand_parse_variant(variant: &ParseVariant) -> syn::Result<TokenStream> {
         quote! { Default::default() }
     };
 
+    let source_option = variant.source_option || is_option;
+
     if is_option {
-        if variant.source_option {
+        if source_option {
             if is_string {
                 parse.extend(quote! {
                     let target = if let Some(target) = target.filter(|target| !target.is_empty()) {
@@ -323,7 +338,7 @@ fn expand_parse_variant(variant: &ParseVariant) -> syn::Result<TokenStream> {
             });
         }
     } else {
-        if variant.source_option {
+        if source_option {
             if variant.default.is_some() {
                 parse.extend(quote! {
                     let target = target.unwrap_or_else(|| #default_expr);