feat: have users preview transaction before signing

cmd/soroban-cli/src/commands/contract/invoke.rs

@@ -28,6 +28,7 @@ use super::super::{
     config::{self, locator},
     events,
 };
+use crate::rpc::preview_txn;
 use crate::commands::NetworkRunnable;
 use crate::{commands::global, rpc, Pwd};
 use soroban_spec_tools::{contract, Spec};
@@ -336,6 +337,7 @@ impl NetworkRunnable for Cmd {
         )?;
         let txn = client.create_assembled_transaction(&tx).await?;
         let txn = self.fee.apply_to_assembled_txn(txn);
+        println!("TXN:\n{}", preview_txn(txn.transaction()));
         let (return_value, events) = if self.is_view() {
             (
                 txn.sim_response().results()?[0].xdr.clone(),

cmd/soroban-cli/src/lib.rs

@@ -3,13 +3,14 @@
     clippy::must_use_candidate,
     clippy::missing_panics_doc
 )]
-pub(crate) use soroban_rpc as rpc;
+
 use std::path::Path;
 
 pub mod commands;
 pub mod fee;
 pub mod key;
 pub mod log;
+pub mod rpc;
 pub mod toid;
 pub mod utils;
 pub mod wasm;

cmd/soroban-cli/src/rpc.rs

@@ -0,0 +1,132 @@
+pub(crate) use soroban_rpc::*;
+use soroban_sdk::xdr;
+
+pub(crate) fn preview_txn(txn: &xdr::Transaction) -> String {
+    let source_account = txn.source_account.to_string();
+    let fee = txn.fee;
+    let operations = txn
+        .operations
+        .iter()
+        .map(preview_operation)
+        .collect::<Vec<_>>()
+        .join("\n");
+    format!("source_account: {source_account}\nfee: {fee}\noperations:\n{operations}")
+}
+
+pub(crate) fn preview_operation(op: &xdr::Operation) -> String {
+    use soroban_sdk::xdr::OperationBody;
+    let _source_account = op.source_account.as_ref().map(ToString::to_string);
+
+    match &op.body {
+        OperationBody::CreateAccount(_) => todo!(),
+        OperationBody::Payment(_) => todo!(),
+        OperationBody::PathPaymentStrictReceive(_) => todo!(),
+        OperationBody::ManageSellOffer(_) => todo!(),
+        OperationBody::CreatePassiveSellOffer(_) => todo!(),
+        OperationBody::SetOptions(_) => todo!(),
+        OperationBody::ChangeTrust(_) => todo!(),
+        OperationBody::AllowTrust(_) => todo!(),
+        OperationBody::AccountMerge(_) => todo!(),
+        OperationBody::Inflation => todo!(),
+        OperationBody::ManageData(_) => todo!(),
+        OperationBody::BumpSequence(_) => todo!(),
+        OperationBody::ManageBuyOffer(_) => todo!(),
+        OperationBody::PathPaymentStrictSend(_) => todo!(),
+        OperationBody::CreateClaimableBalance(_) => todo!(),
+        OperationBody::ClaimClaimableBalance(_) => todo!(),
+        OperationBody::BeginSponsoringFutureReserves(_) => todo!(),
+        OperationBody::EndSponsoringFutureReserves => todo!(),
+        OperationBody::RevokeSponsorship(_) => todo!(),
+        OperationBody::Clawback(_) => todo!(),
+        OperationBody::ClawbackClaimableBalance(_) => todo!(),
+        OperationBody::SetTrustLineFlags(_) => todo!(),
+        OperationBody::LiquidityPoolDeposit(_) => todo!(),
+        OperationBody::LiquidityPoolWithdraw(_) => todo!(),
+        OperationBody::InvokeHostFunction(op) => preview_invoke(op),
+        OperationBody::ExtendFootprintTtl(_) => todo!(),
+        OperationBody::RestoreFootprint(_) => todo!(),
+    }
+}
+
+fn preview_invoke(invoke: &xdr::InvokeHostFunctionOp) -> String {
+    let host_function = preview_host_function(&invoke.host_function);
+    let auth = invoke
+        .auth
+        .iter()
+        .map(preview_auth_entry)
+        .collect::<Vec<_>>()
+        .join("\n");
+    format!("host_function:\n{host_function}\nauth:\n{auth}")
+}
+
+fn preview_host_function(host_function: &xdr::HostFunction) -> String {
+    match host_function {
+        xdr::HostFunction::InvokeContract(args) => preview_invoke_contract_args(args, 1),
+        xdr::HostFunction::CreateContract(_) => todo!(),
+        xdr::HostFunction::UploadContractWasm(_) => todo!(),
+    }
+}
+
+fn preview_invoke_contract_args(args: &xdr::InvokeContractArgs, indention: u8) -> String {
+    let xdr::InvokeContractArgs {
+        contract_address,
+        function_name,
+        args,
+    } = args;
+    let contract_id = match contract_address {
+        xdr::ScAddress::Account(_) => todo!(),
+        xdr::ScAddress::Contract(_) => strkey_from_sc_address(contract_address),
+    };
+    let function_name = function_name.to_string();
+    let args = args.iter().map(|x| format!("{x:?}")).collect::<Vec<_>>();
+    let indent = " ".repeat(indention as usize);
+    format!("{indent}contract_id: {contract_id}\n{indent}function_name: {function_name}\n{indent}args:\n{indent}{args:?}")
+}
+
+fn preview_auth_entry(entry: &xdr::SorobanAuthorizationEntry) -> String {
+    let xdr::SorobanAuthorizationEntry {
+        credentials,
+        root_invocation,
+    } = entry;
+    let function = preview_authorized_function(root_invocation, 1);
+    let account_id = if let xdr::SorobanCredentials::Address(account_id) = &credentials {
+        strkey_from_sc_address(&account_id.address)
+    } else {
+        "SourceAccount".to_string()
+    };
+
+    format!("credentials: {account_id}\n root_invocation:\n{function}")
+}
+
+fn preview_authorized_function(
+    function: &xdr::SorobanAuthorizedInvocation,
+    indention: u8,
+) -> String {
+    let contract_args = match &function.function {
+        xdr::SorobanAuthorizedFunction::ContractFn(args) => {
+            preview_invoke_contract_args(args, indention)
+        }
+        xdr::SorobanAuthorizedFunction::CreateContractHostFn(_) => todo!(),
+    };
+    let mut sub_invocations = String::new();
+    let preview_authorized_function = |x| preview_authorized_function(x, indention + 2);
+    if !function.sub_invocations.is_empty() {
+        sub_invocations = function
+            .sub_invocations
+            .iter()
+            .map(preview_authorized_function)
+            .collect::<Vec<_>>()
+            .join("\n");
+    }
+    let indent = " ".repeat(indention as usize);
+    format!("{indent}contract_args: {contract_args}\n{indent}sub_invocations:\n{sub_invocations}")
+}
+
+fn strkey_from_sc_address(addr: &xdr::ScAddress) -> String {
+    match addr {
+        xdr::ScAddress::Account(xdr::AccountId(xdr::PublicKey::PublicKeyTypeEd25519(
+            xdr::Uint256(bytes),
+        ))) => stellar_strkey::ed25519::PublicKey(*bytes).to_string(),
+        xdr::ScAddress::Contract(contract) => stellar_strkey::Contract(contract.0).to_string(),
+    }
+}