Separate macro and implement trait directly in the macro

Author: dani-garcia

crates/bitwarden-error-macro/src/lib.rs

@@ -5,7 +5,6 @@ mod attribute;
 mod basic;
 mod flat;
 mod full;
-mod wasm_ipc;
 
 /// A procedural macro for generating error types with customizable serialization behavior.
 ///
@@ -121,14 +120,3 @@ pub fn bitwarden_error(
 ) -> proc_macro::TokenStream {
     attribute::bitwarden_error(args, item)
 }
-
-#[proc_macro_attribute]
-pub fn bitwarden_wasm_ipc_channel(
-    args: proc_macro::TokenStream,
-    item: proc_macro::TokenStream,
-) -> proc_macro::TokenStream {
-    match wasm_ipc::bitwarden_wasm_ipc_channel_internal(args, item) {
-        Ok(v) => v,
-        Err(e) => proc_macro::TokenStream::from(e.to_compile_error()),
-    }
-}

crates/bitwarden-ffi-macros/Cargo.toml

@@ -0,0 +1,37 @@
+[package]
+name = "bitwarden-ffi-macros"
+description = """
+Internal crate for the bitwarden crate. Do not use.
+"""
+
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+readme.workspace = true
+homepage.workspace = true
+repository.workspace = true
+license-file.workspace = true
+keywords.workspace = true
+
+[features]
+wasm = []
+
+[dependencies]
+darling = "0.20.10"
+proc-macro2 = "1.0.89"
+quote = "1.0.37"
+syn = "2.0.87"
+
+[lints]
+workspace = true
+
+[lib]
+proc-macro = true
+
+[dev-dependencies]
+js-sys.workspace = true
+serde.workspace = true
+thiserror.workspace = true
+tsify-next.workspace = true
+wasm-bindgen.workspace = true

crates/bitwarden-ffi-macros/README.md

@@ -0,0 +1,3 @@
+# Bitwarden WASM Macros
+
+Provides utility macros for simplifying FFI with WebAssembly and UniFFI.

crates/bitwarden-ffi-macros/src/lib.rs

@@ -0,0 +1,14 @@
+#![doc = include_str!("../README.md")]
+
+mod wasm_ipc;
+
+#[proc_macro_attribute]
+pub fn bitwarden_wasm_ipc_channel(
+    args: proc_macro::TokenStream,
+    item: proc_macro::TokenStream,
+) -> proc_macro::TokenStream {
+    match wasm_ipc::bitwarden_wasm_ipc_channel_internal(args, item) {
+        Ok(v) => v,
+        Err(e) => proc_macro::TokenStream::from(e.to_compile_error()),
+    }
+}

crates/bitwarden-error-macro/src/wasm_ipc.rs renamed to crates/bitwarden-ffi-macros/src/wasm_ipc.rs

@@ -1,5 +1,6 @@
+use darling::{ast::NestedMeta, FromMeta};
 use proc_macro::TokenStream;
-use quote::ToTokens;
+use quote::{quote, ToTokens};
 use syn::{
     parse_quote, spanned::Spanned, Attribute, Error, FnArg, ForeignItem, ForeignItemFn, Ident,
     ItemForeignMod, Pat, ReturnType, Type,
@@ -59,11 +60,20 @@ impl Func {
     }
 }
 
+#[derive(FromMeta)]
+struct WasmIpcArgs {
+    trait_impl: Option<syn::TypePath>,
+    #[darling(default)]
+    async_trait: bool,
+}
+
 pub(crate) fn bitwarden_wasm_ipc_channel_internal(
-    _args: TokenStream,
+    attr: TokenStream,
     item: TokenStream,
 ) -> Result<TokenStream, Error> {
     let mut input = syn::parse::<ItemForeignMod>(item)?;
+    let attr_args = NestedMeta::parse_meta_list(attr.into())?;
+    let attr_args = WasmIpcArgs::from_list(&attr_args)?;
 
     // Validate the ABI
     match input.abi.name {
@@ -148,9 +158,13 @@ pub(crate) fn bitwarden_wasm_ipc_channel_internal(
             quote::quote! { #ident }
         });
 
+        let vis = attr_args.trait_impl.is_none().then(|| {
+            quote::quote! { pub }
+        });
+
         quote::quote! {
             // TODO: Should these return a result?
-            pub async fn #name(&self, #( #args ),*) -> #ret {
+            #vis async fn #name(&self, #( #args ),*) -> #ret {
                 let (tx, rx) = ::tokio::sync::oneshot::channel();
                 self.sender.send(#channel_command_ident::#name {
                     _internal_respond_to: tx,
@@ -161,6 +175,27 @@ pub(crate) fn bitwarden_wasm_ipc_channel_internal(
         }
     });
 
+    let channel_impl = if let Some(trait_impl) = &attr_args.trait_impl {
+        let async_trait = attr_args.async_trait.then(|| {
+            quote::quote! {
+                #[async_trait::async_trait]
+            }
+        });
+
+        quote! {
+            #async_trait
+            impl #trait_impl for #channel_ident {
+                #( #impls )*
+            }
+        }
+    } else {
+        quote! {
+            impl #channel_ident {
+                #( #impls )*
+            }
+        }
+    };
+
     let matches = functions.iter().map(|f| {
         let name = &f.name;
         let args: Vec<_> = f.args.iter().map(|(ident, _)| {
@@ -216,9 +251,7 @@ pub(crate) fn bitwarden_wasm_ipc_channel_internal(
             }
         }
 
-        impl #channel_ident {
-            #( #impls )*
-        }
+    #channel_impl
     }
     .into())
 }

crates/bitwarden-wasm-internal/Cargo.toml

@@ -20,6 +20,7 @@ async-trait = ">=0.1.80, <0.2"
 bitwarden-core = { workspace = true, features = ["wasm", "internal"] }
 bitwarden-crypto = { workspace = true, features = ["wasm"] }
 bitwarden-error = { workspace = true }
+bitwarden-ffi-macros = { workspace = true }
 bitwarden-ipc = { workspace = true, features = ["wasm"] }
 bitwarden-ssh = { workspace = true, features = ["wasm"] }
 bitwarden-vault = { workspace = true, features = ["wasm"] }

crates/bitwarden-wasm-internal/src/client.rs

@@ -84,7 +84,10 @@ export interface CipherStore {
 }
 "#;
 
-#[bitwarden_error::bitwarden_wasm_ipc_channel]
+#[bitwarden_ffi_macros::bitwarden_wasm_ipc_channel(
+    trait_impl = "DataStore<Cipher>",
+    async_trait = true
+)]
 #[wasm_bindgen]
 extern "C" {
     #[wasm_bindgen(js_name = CipherStore, typescript_type = "CipherStore")]
@@ -103,6 +106,7 @@ extern "C" {
     async fn remove(this: &JSCipherStore, id: String);
 }
 
+/*
 #[async_trait::async_trait]
 impl DataStore<Cipher> for ChannelJSCipherStore {
     async fn get(&self, id: String) -> Option<Cipher> {
@@ -120,7 +124,7 @@ impl DataStore<Cipher> for ChannelJSCipherStore {
     async fn remove(&self, id: String) {
         ChannelJSCipherStore::remove(self, id).await;
     }
-}
+}*/
 
 #[wasm_bindgen]
 impl StoreClient {