add tests and fix mechanism

test_program_methods/guest/Cargo.toml

@@ -11,6 +11,7 @@ workspace = true
 nssa_core.workspace = true
 authenticated_transfer_core.workspace = true
 clock_core.workspace = true
+faucet_core.workspace = true
 
 risc0-zkvm.workspace = true
 serde = { workspace = true, default-features = false }

test_program_methods/guest/src/bin/faucet_chain_caller.rs

@@ -0,0 +1,50 @@
+use nssa_core::{
+    account::AccountId,
+    program::{AccountPostState, ChainedCall, ProgramId, ProgramInput, ProgramOutput, read_nssa_inputs},
+};
+use risc0_zkvm::serde::to_vec;
+
+type Instruction = (ProgramId, ProgramId, AccountId, u128);
+// (faucet_program_id, vault_program_id, recipient_id, amount)
+
+fn main() {
+    let (
+        ProgramInput {
+            self_program_id,
+            caller_program_id,
+            pre_states,
+            instruction: (faucet_program_id, vault_program_id, recipient_id, amount),
+        },
+        instruction_words,
+    ) = read_nssa_inputs::<Instruction>();
+
+    let post_states: Vec<_> = pre_states
+        .iter()
+        .map(|pre| AccountPostState::new(pre.account.clone()))
+        .collect();
+
+    assert_eq!(pre_states.len(), 2);
+    let [faucet_pre, vault_pda_pre] = [pre_states[0].clone(), pre_states[1].clone()];
+
+    let chained_calls = vec![ChainedCall {
+        program_id: faucet_program_id,
+        instruction_data: to_vec(&faucet_core::Instruction::Transfer {
+            vault_program_id,
+            recipient_id,
+            amount,
+        })
+        .unwrap(),
+        pre_states: vec![faucet_pre, vault_pda_pre],
+        pda_seeds: vec![],
+    }];
+
+    ProgramOutput::new(
+        self_program_id,
+        caller_program_id,
+        instruction_words,
+        pre_states,
+        post_states,
+    )
+    .with_chained_calls(chained_calls)
+    .write();
+}