Update syn requirement from 2.0 to 3.0

juniper_codegen/CHANGELOG.md

@@ -18,6 +18,10 @@ All user visible changes to `juniper_codegen` crate will be documented in this f
         - Placing `#[graphql(deprecated)]` attribute on method arguments in `#[graphql_object]` and `#[graphql_interface]` macros.
 - Support of `#[graphql(rename_all = "snake_case")]` attribute. ([#1354])
 
+### Changed
+
+- Migrated to [3.0][syn-3.0] version of [`syn`] crate. ([#1389])
+
 ### Fixed
 
 - Memory leak caused by incorrect error handling in `#[graphql_subscription]` macro expansion. ([#1371])
@@ -29,9 +33,11 @@ All user visible changes to `juniper_codegen` crate will be documented in this f
 [#1348]: /../../pull/1348
 [#1354]: /../../pull/1354
 [#1371]: /../../pull/1371
+[#1389]: /../../pull/1389
 [graphql/graphql-spec#525]: https://github.com/graphql/graphql-spec/pull/525
 [graphql/graphql-spec#805]: https://github.com/graphql/graphql-spec/pull/805
 [graphql/graphql-spec#825]: https://github.com/graphql/graphql-spec/pull/825
+[syn-3.0]: https://github.com/dtolnay/syn/releases/tag/3.0.0
 
 
 
@@ -111,7 +117,7 @@ All user visible changes to `juniper_codegen` crate will be documented in this f
 
 ### Changed
 
-- Migrated to 2 version of `syn` crate. ([#1157])
+- Migrated to [2.0][syn-2.0] version of [`syn`] crate. ([#1157])
 
 ### Fixed
 
@@ -133,10 +139,12 @@ All user visible changes to `juniper_codegen` crate will be documented in this f
 [#1054]: /../../pull/1054
 [#1157]: /../../pull/1157
 [#1245]: /../../pull/1245
+[syn-2.0]: https://github.com/dtolnay/syn/releases/tag/2.0.0
 
 
 
 
+[`syn`]: https://docs.rs/syn
 [MSRV]: https://doc.rust-lang.org/cargo/reference/manifest.html#the-rust-version-field
 [orphan rules]: https://doc.rust-lang.org/reference/items/implementations.html#orphan-rules
 [Semantic Versioning 2.0.0]: https://semver.org

juniper_codegen/Cargo.toml

@@ -25,7 +25,7 @@ proc-macro = true
 derive_more = { version = "2.0", features = ["as_ref", "deref", "display"] }
 proc-macro2 = "1.0.4"
 quote = "1.0.9"
-syn = { version = "2.0", features = ["extra-traits", "full", "visit", "visit-mut"] }
+syn = { version = "3.0", features = ["extra-traits", "full", "visit", "visit-mut"] }
 url = "2.0"
 
 [dev-dependencies]

juniper_codegen/src/common/parse/downcaster.rs

@@ -22,7 +22,9 @@ pub(crate) fn output_type(ret_ty: &syn::ReturnType) -> Result<syn::Type, Span> {
     };
 
     let path = match ret_ty.unparenthesized() {
-        syn::Type::Path(syn::TypePath { qself: None, path }) => path,
+        syn::Type::Path(syn::TypePath {
+            qself: None, path, ..
+        }) => path,
         _ => return Err(ret_ty.span()),
     };
 
@@ -66,7 +68,8 @@ pub(crate) fn output_type(ret_ty: &syn::ReturnType) -> Result<syn::Type, Span> {
 pub(crate) fn context_ty(sig: &syn::Signature) -> Result<Option<syn::Type>, Span> {
     match sig.receiver() {
         Some(rcv) => {
-            if rcv.reference.is_none() || rcv.mutability.is_some() {
+            // Only `&self` is expected in method's signature.
+            if !matches!(rcv.kind, syn::ReceiverKind::Reference(_, _, None)) {
                 return Err(rcv.span());
             }
         }

juniper_codegen/src/common/parse/mod.rs

@@ -157,8 +157,8 @@ impl TypeExt for syn::Type {
                         }
                     }
                     syn::PathArguments::Parenthesized(args) => {
-                        for ty in args.inputs.iter_mut() {
-                            ty.lifetimes_iter_mut(func)
+                        for arg in args.inputs.iter_mut() {
+                            arg.ty.lifetimes_iter_mut(func)
                         }
                         if let syn::ReturnType::Type(_, ty) = &mut args.output {
                             (*ty).lifetimes_iter_mut(func)
@@ -213,7 +213,7 @@ impl TypeExt for syn::Type {
             T::Path(ty) => iter_path(&mut ty.path, func),
 
             // These types unlikely will be used as GraphQL types.
-            T::BareFn(_) | T::Infer(_) | T::Macro(_) | T::Never(_) | T::Verbatim(_) => {}
+            T::FnPtr(_) | T::Infer(_) | T::Macro(_) | T::Never(_) | T::Verbatim(_) => {}
 
             // Following the `syn` idiom for exhaustive matching on `Type`:
             // https://docs.rs/syn/2.0.38/src/syn/ty.rs.html#64-79

juniper_codegen/src/graphql_object/attr.rs

@@ -187,7 +187,7 @@ fn parse_field(
         if let Some(arg) = method.sig.inputs.first() {
             match arg {
                 syn::FnArg::Receiver(rcv) => {
-                    if rcv.reference.is_none() || rcv.mutability.is_some() {
+                    if !matches!(rcv.kind, syn::ReceiverKind::Reference(_, _, None)) {
                         return err_invalid_method_receiver(rcv);
                     }
                 }

juniper_codegen/src/scalar_value/mod.rs

@@ -429,7 +429,7 @@ impl TryFrom<syn::Fields> for Field {
     fn try_from(value: syn::Fields) -> Result<Self, Self::Error> {
         match value {
             syn::Fields::Named(mut f) if f.named.len() == 1 => {
-                Ok(Self::Named(Box::new(f.named.pop().unwrap().into_value())))
+                Ok(Self::Named(Box::new(f.named.pop().unwrap())))
             }
             syn::Fields::Unnamed(f) if f.unnamed.len() == 1 => Ok(Self::Unnamed),
             _ => Err(ERR.custom_error(value.span(), "expected exactly 1 field")),