feat: add stellar_asset! macro. Resolves a token client at compile (#…

…133)

Currently you need to hard code the contract ids of existing SAC contracts like "native". This allows this to be resolved at compile time. It does currently require that STELLAR_NETWORK be `local`, `testnet`, `futurenet` or `mainnet` and defaults to `local`.

Cargo.toml

@@ -14,8 +14,12 @@ loam-soroban-sdk = { path = "./crates/loam-soroban-sdk" }
 loam-sdk-macro = { path = "./crates/loam-sdk-macro" }
 loam-subcontract-ft = { path = "./crates/loam-subcontract-ft" }
 
+soroban-sdk = { version = "21.2.0" }
+stellar-strkey = "0.0.8"
+
 cargo_metadata = "0.18.1"
 thiserror = "1.0.38"
+sha2 = "0.10.7"
 
 [profile.contracts]
 inherits = "release"

crates/loam-cli/Cargo.toml

@@ -37,6 +37,9 @@ clap = { version = "4.1.8", features = [
 ] }
 
 cargo_metadata = { workspace = true }
+sha2 = { workspace = true }
+
+
 clap-cargo-extra = "0.3.0"
 
 thiserror = "1.0.31"
@@ -52,7 +55,6 @@ ignore = "0.4"
 strsim = "0.11.1"
 heck = "0.5.0"
 pathdiff = "0.2.1"
-sha2 = "0.10.7"
 hex = "0.4.3"
 shlex = "1.1.0"
 symlink = "0.1.0"

crates/loam-cli/examples/soroban/wallet/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "example-wallet"
+version = "0.0.0"
+authors = ["Stellar Development Foundation <[email protected]>"]
+license = "Apache-2.0"
+edition = "2021"
+publish = false
+
+[lib]
+crate-type = ["cdylib"]
+doctest = false
+
+[dependencies]
+loam-sdk = { workspace = true, features = ["loam-soroban-sdk"] }
+loam-subcontract-core = { workspace = true }
+
+
+[dev_dependencies]
+loam-sdk = { workspace = true, features = ["soroban-sdk-testutils"] }

crates/loam-cli/examples/soroban/wallet/src/error.rs

@@ -0,0 +1,9 @@
+use loam_sdk::soroban_sdk::{self, contracterror};
+
+#[contracterror]
+#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[repr(u32)]
+pub enum Error {
+    /// The operation results in an integer overflow
+    Overflow = 1,
+}

crates/loam-cli/examples/soroban/wallet/src/lib.rs

@@ -0,0 +1,11 @@
+#![no_std]
+use loam_subcontract_core::{admin::Admin, Core};
+
+pub mod error;
+pub mod subcontract;
+
+pub use error::Error;
+use subcontract::{Calculator, Token};
+
+#[loam_sdk::derive_contract(Core(Admin), Token(Calculator))]
+pub struct Contract;

crates/loam-cli/examples/soroban/wallet/src/subcontract.rs

@@ -0,0 +1,36 @@
+use loam_sdk::{
+    soroban_sdk::{env, token, Address, Lazy},
+    stellar_asset, subcontract,
+};
+
+#[derive(Lazy, Default)]
+pub struct Calculator;
+
+#[subcontract]
+pub trait IsToken {
+    /// Get contract's xlm balance
+    #[allow(clippy::missing_errors_doc)]
+    fn balance(&self) -> i128;
+
+    /// Puts two into into a vector
+    fn transfer(&self, to: loam_sdk::soroban_sdk::Address, amount: i128);
+
+    fn addr(&self) -> loam_sdk::soroban_sdk::Address;
+}
+
+fn native() -> token::Client<'static> {
+    stellar_asset!("native")
+}
+
+impl IsToken for Calculator {
+    fn balance(&self) -> i128 {
+        native().balance(&env().current_contract_address())
+    }
+
+    fn transfer(&self, to: Address, amount: i128) {
+        native().transfer(&env().current_contract_address(), &to, &amount);
+    }
+    fn addr(&self) -> loam_sdk::soroban_sdk::Address {
+        native().address
+    }
+}

crates/loam-cli/tests/it/build_clients/init_script.rs

@@ -85,7 +85,7 @@ STELLAR_ACCOUNT=bob mint --amount 2000000 --to bob
         assert!(String::from_utf8_lossy(&output.stderr).contains(
             "✅ Initialization script for \"soroban_token_contract\" completed successfully"
         ));
-    })
+    });
 }
 
 #[test]

crates/loam-sdk-macro/Cargo.toml

@@ -12,6 +12,11 @@ proc-macro = true
 
 [dependencies]
 loam-build = { path = "../loam-build", version = "0.7.3" }
+
+soroban-sdk = { workspace = true, features = ["testutils"] }
+stellar-strkey = { workspace = true }
+
+sha2 = { workspace = true }
 proc-macro2 = "1.0"
 syn = { version = "2", features = ["full", "fold", "extra-traits", "visit"] }
 quote = "1.0"
@@ -20,7 +25,8 @@ thiserror = { workspace = true }
 syn-file-expand = "0.3.0"
 cargo_metadata = { workspace = true }
 darling = "0.20.8"
-itertools = "0.12.1"
+itertools = "0.13.0"
+regex = "1.10.5"
 
 [dev-dependencies]
 assert_fs = "1.0.13"

crates/loam-sdk-macro/src/lib.rs

@@ -108,3 +108,20 @@ pub fn derive_contract(args: TokenStream, item: TokenStream) -> TokenStream {
     let parsed: Item = syn::parse(item.clone()).expect("failed to parse Item");
     derive_contract_impl(proc_macro2::TokenStream::from(args), parsed).into()
 }
+
+/// Generates a contract Client for a given asset.
+/// It is expected that the name of an asset, e.g. "native" or "USDC:G1...."
+///
+/// # Panics
+///
+
+#[proc_macro]
+pub fn stellar_asset(input: TokenStream) -> TokenStream {
+    // Parse the input as a string literal
+    let input_str = syn::parse_macro_input!(input as syn::LitStr);
+    let network = std::env::var("STELLAR_NETWORK").unwrap_or_else(|_| "local".to_owned());
+    let asset = util::parse_asset_literal(&input_str, &network);
+
+    // Return the generated code as a TokenStream
+    asset.into()
+}

crates/loam-sdk-macro/src/subcontract.rs

@@ -250,37 +250,8 @@ fn group_to_ident(g: &Group) -> Ident {
 #[cfg(test)]
 mod tests {
 
-    use std::io::{Read, Write};
-
-    /// Format the given snippet. The snippet is expected to be *complete* code.
-    /// When we cannot parse the given snippet, this function returns `None`.
-    fn format_snippet(snippet: &str) -> String {
-        let mut child = std::process::Command::new("rustfmt")
-            .stdin(std::process::Stdio::piped())
-            .stdout(std::process::Stdio::piped())
-            .spawn()
-            .unwrap();
-        child
-            .stdin
-            .as_mut()
-            .unwrap()
-            .write_all(snippet.as_bytes())
-            .map_err(p_e)
-            .unwrap();
-        child.wait().unwrap();
-        let mut buf = String::new();
-        child.stdout.unwrap().read_to_string(&mut buf).unwrap();
-        println!("\n\n\n{buf}\n\n\n");
-        buf
-    }
     use super::*;
-
-    fn equal_tokens(expected: &TokenStream, actual: &TokenStream) {
-        assert_eq!(
-            format_snippet(&expected.to_string()),
-            format_snippet(&actual.to_string())
-        );
-    }
+    use crate::util::*;
 
     #[test]
     fn first() {
@@ -375,8 +346,4 @@ mod tests {
         // let impl_ = syn::parse_str::<ItemImpl>(result.as_str()).unwrap();
         // println!("{impl_:#?}");
     }
-    fn p_e(e: std::io::Error) -> std::io::Error {
-        eprintln!("{e:#?}");
-        e
-    }
 }