WIP: Add generic async support

.github/workflows/rust.yml

@@ -20,7 +20,7 @@ jobs:
   tests:
     strategy:
       matrix:
-        rust_version: [1.67, stable]
+        rust_version: [1.75.0, stable]
     runs-on: ubuntu-20.04
 
     steps:

Cargo.toml

@@ -1,7 +1,9 @@
 [workspace]
+resolver = "2"
 members = ["borsh", "borsh-derive", "fuzz/fuzz-run", "benchmarks"]
 
 [workspace.package]
 # shared version of all public crates in the workspace
 version = "1.5.5"
-rust-version = "1.67.0"
+edition = "2021"
+rust-version = "1.75.0"

benchmarks/Cargo.toml

@@ -3,7 +3,7 @@ name = "benchmarks"
 version.workspace = true
 rust-version.workspace = true
 authors = ["Near Inc <[email protected]>"]
-edition = "2018"
+edition.workspace = true
 publish = false
 
 # This is somehow needed for command line arguments to work: https://github.com/bheisler/criterion.rs/issues/193#issuecomment-415740713

borsh-derive/Cargo.toml

@@ -3,7 +3,7 @@ name = "borsh-derive"
 version.workspace = true
 rust-version.workspace = true
 authors = ["Near Inc <[email protected]>"]
-edition = "2018"
+edition.workspace = true
 license = "Apache-2.0"
 readme = "README.md"
 categories = ["encoding", "network-programming"]
@@ -18,14 +18,14 @@ exclude = ["*.snap"]
 proc-macro = true
 
 [dependencies]
-syn = { version = "2.0.81", features = ["full", "fold"] }
+syn = { version = "2.0.96", features = ["full", "fold"] }
 proc-macro-crate = "3"
-proc-macro2 = "1"
-quote = "1"
+proc-macro2 = "1.0"
+quote = "1.0"
 once_cell = "1.18.0"
 
 [dev-dependencies]
-syn = { version = "2.0.81", features = ["full", "fold", "parsing"] }
+syn = { version = "2.0.96", features = ["parsing"] }
 prettyplease = "0.2.9"
 insta = "1.29.0"
 

borsh-derive/src/lib.rs

@@ -52,10 +52,7 @@ pub fn borsh_serialize(input: TokenStream) -> TokenStream {
         // Derive macros can only be defined on structs, enums, and unions.
         unreachable!()
     };
-    TokenStream::from(match res {
-        Ok(res) => res,
-        Err(err) => err.to_compile_error(),
-    })
+    TokenStream::from(res.unwrap_or_else(|err| err.to_compile_error()))
 }
 
 /// ---
@@ -80,10 +77,7 @@ pub fn borsh_deserialize(input: TokenStream) -> TokenStream {
         // Derive macros can only be defined on structs, enums, and unions.
         unreachable!()
     };
-    TokenStream::from(match res {
-        Ok(res) => res,
-        Err(err) => err.to_compile_error(),
-    })
+    TokenStream::from(res.unwrap_or_else(|err| err.to_compile_error()))
 }
 
 /// ---
@@ -104,16 +98,13 @@ pub fn borsh_schema(input: TokenStream) -> TokenStream {
     } else if let Ok(input) = syn::parse::<ItemEnum>(input.clone()) {
         schema::enums::process(&input, cratename)
     } else if syn::parse::<ItemUnion>(input).is_ok() {
-        Err(syn::Error::new(
+        Err(Error::new(
             Span::call_site(),
             "Borsh schema does not support unions yet.",
         ))
     } else {
         // Derive macros can only be defined on structs, enums, and unions.
         unreachable!()
     };
-    TokenStream::from(match res {
-        Ok(res) => res,
-        Err(err) => err.to_compile_error(),
-    })
+    TokenStream::from(res.unwrap_or_else(|err| err.to_compile_error()))
 }

borsh/Cargo.toml

@@ -3,7 +3,7 @@ name = "borsh"
 version.workspace = true
 rust-version.workspace = true
 authors = ["Near Inc <[email protected]>"]
-edition = "2018"
+edition.workspace = true
 license = "MIT OR Apache-2.0"
 readme = "README.md"
 categories = ["encoding", "network-programming"]
@@ -41,7 +41,12 @@ hashbrown = { version = ">=0.11,<0.16.0", optional = true }
 bytes = { version = "1", optional = true }
 bson = { version = "2", optional = true }
 
+async-generic = { git = "https://github.com/DanikVitek/async-generic.git", rev = "392e8ef432c9bf4ca381262f56e192a27136e04f" }
+tokio = { version = "1", default-features = false, features = ["io-util"], optional = true }
+async-std = { version = "1", default-features = false, features = ["std"], optional = true }
+
 [dev-dependencies]
+tokio-test = "0.4.4"
 insta = "1.29.0"
 serde_json = { version = "1" }
 
@@ -52,6 +57,9 @@ targets = ["x86_64-unknown-linux-gnu"]
 [features]
 default = ["std"]
 derive = ["borsh-derive"]
+async = []
+tokio = ["async", "dep:tokio"]
+async-std = ["async", "dep:async-std"]
 unstable__schema = ["derive", "borsh-derive/schema"]
 std = []
 # Opt into impls for Rc<T> and Arc<T>. Serializing and deserializing these types

borsh/examples/serde_json_value.rs

@@ -3,14 +3,18 @@ use std::collections::HashMap;
 use borsh::{BorshDeserialize, BorshSerialize};
 
 mod serde_json_value {
+    #[allow(unused_imports)] // used in attribute
     pub use de::deserialize_value;
+    #[allow(unused_imports)] // used in attribute
     pub use ser::serialize_value;
+
     mod ser {
+        use core::convert::TryFrom;
+
         use borsh::{
             io::{ErrorKind, Result, Write},
             BorshSerialize,
         };
-        use core::convert::TryFrom;
 
         /// this is mutually recursive with `serialize_array` and `serialize_map`
         pub fn serialize_value<W: Write>(value: &serde_json::Value, writer: &mut W) -> Result<()> {