Test epoch rewards sysvar in program test (#32293)

* Add epoch rewards sysvar test to program test

* Add a test to check epoch rewards sysvar inside/outisde reward interval

---------

Co-authored-by: HaoranYi <haoran.yi@solana.com>

program-test/src/lib.rs

@@ -362,6 +362,13 @@ impl solana_sdk::program_stubs::SyscallStubs for SyscallStubs {
         )
     }
 
+    fn sol_get_epoch_rewards_sysvar(&self, var_addr: *mut u8) -> u64 {
+        get_sysvar(
+            get_invoke_context().get_sysvar_cache().get_epoch_rewards(),
+            var_addr,
+        )
+    }
+
     #[allow(deprecated)]
     fn sol_get_fees_sysvar(&self, var_addr: *mut u8) -> u64 {
         get_sysvar(get_invoke_context().get_sysvar_cache().get_fees(), var_addr)

program-test/tests/sysvar.rs

@@ -2,8 +2,8 @@ use {
     solana_program_test::{processor, ProgramTest},
     solana_sdk::{
         account_info::AccountInfo, clock::Clock, entrypoint::ProgramResult,
-        epoch_schedule::EpochSchedule, instruction::Instruction, msg, pubkey::Pubkey, rent::Rent,
+        epoch_rewards::EpochRewards, epoch_schedule::EpochSchedule, instruction::Instruction, msg,
-        signature::Signer, sysvar::Sysvar, transaction::Transaction,
+        pubkey::Pubkey, rent::Rent, signature::Signer, sysvar::Sysvar, transaction::Transaction,
     },
 };
 
@@ -53,3 +53,77 @@ async fn get_sysvar() {
         .await
         .unwrap();
 }
+
+fn epoch_reward_sysvar_getter_process_instruction(
+    _program_id: &Pubkey,
+    _accounts: &[AccountInfo],
+    input: &[u8],
+) -> ProgramResult {
+    msg!("epoch_reward_sysvar_getter");
+
+    // input[0] == 0 indicates the bank is not in reward period.
+    // input[0] == 1 indicates the bank is in reward period.
+    if input[0] == 0 {
+        // epoch rewards sysvar should not exist for banks that are not in reward period
+        let epoch_rewards = EpochRewards::get();
+        assert!(epoch_rewards.is_err());
+    } else {
+        let _epoch_rewards = EpochRewards::get()?;
+    }
+
+    Ok(())
+}
+
+#[tokio::test]
+async fn get_epoch_rewards_sysvar() {
+    let program_id = Pubkey::new_unique();
+    let program_test = ProgramTest::new(
+        "epoch_reward_sysvar_getter",
+        program_id,
+        processor!(epoch_reward_sysvar_getter_process_instruction),
+    );
+
+    let mut context = program_test.start_with_context().await;
+
+    // wrap to 1st slot before next epoch (outside reward interval)
+    let first_normal_slot = context.genesis_config().epoch_schedule.first_normal_slot;
+    let slots_per_epoch = context.genesis_config().epoch_schedule.slots_per_epoch;
+    let last_slot_before_new_epoch = first_normal_slot
+        .saturating_add(slots_per_epoch)
+        .saturating_sub(1);
+    context.warp_to_slot(last_slot_before_new_epoch).unwrap();
+
+    // outside of reward interval, set input[0] == 0, so that the program assert that epoch_rewards sysvar doesn't exist.
+    let instructions = vec![Instruction::new_with_bincode(program_id, &[0u8], vec![])];
+    let transaction = Transaction::new_signed_with_payer(
+        &instructions,
+        Some(&context.payer.pubkey()),
+        &[&context.payer],
+        context.last_blockhash,
+    );
+
+    context
+        .banks_client
+        .process_transaction(transaction)
+        .await
+        .unwrap();
+
+    // wrap to 1st slot of next epoch (inside reward interval)
+    let first_slot_in_new_epoch = first_normal_slot.saturating_add(slots_per_epoch);
+    context.warp_to_slot(first_slot_in_new_epoch).unwrap();
+
+    // inside of reward interval, set input[0] == 1, so that the program assert that epoch_rewards sysvar exist.
+    let instructions = vec![Instruction::new_with_bincode(program_id, &[1u8], vec![])];
+    let transaction = Transaction::new_signed_with_payer(
+        &instructions,
+        Some(&context.payer.pubkey()),
+        &[&context.payer],
+        context.last_blockhash,
+    );
+
+    context
+        .banks_client
+        .process_transaction(transaction)
+        .await
+        .unwrap();
+}

sdk/src/lib.rs

@@ -46,9 +46,9 @@ pub use solana_program::{
     account_info, address_lookup_table_account, alt_bn128, big_mod_exp, blake3, borsh, bpf_loader,
     bpf_loader_deprecated, bpf_loader_upgradeable, clock, config, custom_heap_default,
     custom_panic_default, debug_account_data, declare_deprecated_sysvar_id, declare_sysvar_id,
-    decode_error, ed25519_program, epoch_schedule, fee_calculator, impl_sysvar_get, incinerator,
+    decode_error, ed25519_program, epoch_rewards, epoch_schedule, fee_calculator, impl_sysvar_get,
-    instruction, keccak, lamports, loader_instruction, loader_upgradeable_instruction, loader_v4,
+    incinerator, instruction, keccak, lamports, loader_instruction, loader_upgradeable_instruction,
-    loader_v4_instruction, message, msg, native_token, nonce, program, program_error,
+    loader_v4, loader_v4_instruction, message, msg, native_token, nonce, program, program_error,
     program_memory, program_option, program_pack, rent, sanitize, sdk_ids, secp256k1_program,
     secp256k1_recover, serde_varint, serialize_utils, short_vec, slot_hashes, slot_history,
     stable_layout, stake, stake_history, syscalls, system_instruction, system_program, sysvar,