test: add get_stakers 100% power test (#34)

<!-- Reviewable:start -->
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/starkware-libs/starknet-staking/34)
<!-- Reviewable:end -->

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Adds a flow test asserting `get_stakers` returns 100% staking power with BTC delegation and exposes `STAKING_POWER_BASE_VALUE` for use.
> 
> - **Tests**:
>   - Add `get_stakers_staking_power_100_flow_test` in `src/flow_test/test.cairo` to verify staking power equals `STAKING_POWER_BASE_VALUE` when delegating BTC to a single staker.
> - **Utils**:
>   - Make `STAKING_POWER_BASE_VALUE` `pub(crate)` in `src/staking/utils.cairo` and import it in tests.
> 
> <sup>Written by [Cursor Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit 21f569c. This will update automatically on new commits. Configure [here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: arad-starkware

src/flow_test/test.cairo

@@ -10,7 +10,7 @@ use staking::pool::pool::Pool;
 use staking::pool::pool::Pool::STRK_CONFIG;
 use staking::pool::utils::compute_rewards_rounded_down;
 use staking::staking::interface::{IStakingConsensusDispatcherTrait, IStakingDispatcherTrait};
-use staking::staking::utils::{BTC_WEIGHT_FACTOR, STRK_WEIGHT_FACTOR};
+use staking::staking::utils::{BTC_WEIGHT_FACTOR, STAKING_POWER_BASE_VALUE, STRK_WEIGHT_FACTOR};
 use staking::test_utils::constants::{
     BTC_18D_CONFIG, BTC_5D_CONFIG, BTC_8D_CONFIG, PUBLIC_KEY, STRK_BASE_VALUE,
     TEST_MIN_BTC_FOR_REWARDS,
@@ -2585,3 +2585,37 @@ fn get_stakers_switch_delegation_flow_test() {
     assert!(stakers == expected_stakers);
 }
 
+/// Flow:
+/// Staker stake.
+/// Delegator delegate BTC.
+/// Test staking power in get_stakers is 100%.
+#[test]
+fn get_stakers_staking_power_100_flow_test() {
+    let cfg: StakingInitConfig = Default::default();
+    let mut system = SystemConfigTrait::basic_stake_flow_cfg(:cfg).deploy();
+    let stake_amount = system.staking.get_min_stake();
+    let btc_delegation_amount = TEST_MIN_BTC_FOR_REWARDS;
+    let staking_consensus = system.staking.consensus_dispatcher();
+    let staker = system.new_staker(amount: stake_amount);
+    system.stake(staker: staker, amount: stake_amount, pool_enabled: true, commission: 200);
+    let btc_pool = system
+        .set_open_for_delegation(
+            staker: staker, token_address: system.btc_token.contract_address(),
+        );
+    let delegator = system
+        .new_btc_delegator(amount: btc_delegation_amount, token: system.btc_token);
+    system
+        .delegate_btc(
+            delegator: delegator,
+            pool: btc_pool,
+            amount: btc_delegation_amount,
+            token: system.btc_token,
+        );
+    system.advance_k_epochs();
+
+    // Test get_stakers.
+    let stakers = staking_consensus.get_stakers(epoch_id: system.staking.get_current_epoch());
+    let expected_stakers = array![(staker.staker.address, STAKING_POWER_BASE_VALUE, Option::None)]
+        .span();
+    assert!(stakers == expected_stakers);
+}

src/staking/utils.cairo

@@ -23,7 +23,7 @@ use starkware_utils::storage::iterable_map::{
 };
 use starkware_utils::trace::trace::{Trace, TraceTrait};
 
-const STAKING_POWER_BASE_VALUE: u128 = 10_u128.pow(10);
+pub(crate) const STAKING_POWER_BASE_VALUE: u128 = 10_u128.pow(10);
 pub(crate) const STRK_WEIGHT_FACTOR: u128 = STAKING_POWER_BASE_VALUE
     * (ALPHA_DENOMINATOR - ALPHA)
     / ALPHA_DENOMINATOR;