Cross-Program Invocation
How to test programs calling other programs
Complete Test
use litesvm::LiteSVM;
use solana_sdk::{
instruction::{AccountMeta, Instruction},
pubkey::Pubkey,
signature::{Keypair, Signer},
transaction::Transaction,
system_program,
};
#[test]
fn test_cross_program_invocation() {
let mut svm = LiteSVM::new();
// Deploy both programs
let caller_program = Pubkey::new_unique();
let callee_program = Pubkey::new_unique();
svm.add_program(
caller_program,
include_bytes!("../target/deploy/caller.so")
).unwrap();
svm.add_program(
callee_program,
include_bytes!("../target/deploy/callee.so")
).unwrap();
// Setup accounts
let payer = Keypair::new();
svm.airdrop(&payer.pubkey(), 10_000_000_000).unwrap();
// Create instruction that will trigger CPI
let instruction = Instruction {
program_id: caller_program,
accounts: vec![
AccountMeta::new(payer.pubkey(), true),
AccountMeta::new_readonly(callee_program, false),
AccountMeta::new_readonly(system_program::id(), false),
],
data: vec![1], // Instruction to trigger CPI
};
let tx = Transaction::new_signed_with_payer(
&[instruction],
Some(&payer.pubkey()),
&[&payer],
svm.latest_blockhash(),
);
let result = svm.send_transaction(tx).unwrap();
// Verify both programs were invoked
assert!(result.logs.iter().any(|log|
log.contains(&format!("Program {} invoke", caller_program))
));
assert!(result.logs.iter().any(|log|
log.contains(&format!("Program {} invoke", callee_program))
));
println!("CPI successful!");
println!("Logs showing both programs:");
for log in &result.logs {
if log.contains("invoke") {
println!(" {}", log);
}
}
}
Key Points
- Multiple Programs: Deploy all programs involved in the CPI chain
- Program IDs: Pass the callee program ID as an account in the instruction
- System Program: Often needed for CPI operations (transfers, account creation, etc.)
- Log Verification: Check logs to verify all programs in the call chain executed
For more detailed deployment information, read this section.
Understanding CPI Logs
When a CPI occurs, you'll see logs like:
Program A invoke [1]
Program B invoke [2]
Program B success
Program A success
The numbers in brackets indicate the call depth.