Enfornce rate limits on decrease_take

pallets/subtensor/src/staking.rs

@@ -155,8 +155,17 @@ impl<T: Config> Pallet<T> {
         let min_take = MinTake::<T>::get();
         ensure!(take >= min_take, Error::<T>::DelegateTakeTooLow);
 
-        // Set last block for rate limiting
+        // --- 5. Enforce the rate limit (independently on do_add_stake rate limits)
         let block: u64 = Self::get_current_block_as_u64();
+        ensure!(
+            !Self::exceeds_tx_delegate_take_rate_limit(
+                Self::get_last_tx_block_delegate_take(&coldkey),
+                block
+            ),
+            Error::<T>::DelegateTxRateLimitExceeded
+        );
+
+        // Set last block for rate limiting
         Self::set_last_tx_block_delegate_take(&coldkey, block);
 
         // --- 4. Set the new take value.

pallets/subtensor/tests/staking.rs

@@ -2824,6 +2824,9 @@ fn test_can_set_min_take_ok() {
             u16::MAX / 10
         ));
 
+        // Wait so that we can decrease take
+        step_block(1 + InitialTxDelegateTakeRateLimit::get() as u16);
+
         // Coldkey / hotkey 0 decreases take to min
         assert_ok!(SubtensorModule::do_decrease_take(
             <<Test as Config>::RuntimeOrigin>::signed(coldkey0),
@@ -3136,7 +3139,7 @@ fn test_rate_limits_enforced_on_increase_take() {
     });
 }
 
-// Test rate-limiting on increase_take
+// Test rate-limiting on decrease_take + increase_take
 #[test]
 fn test_rate_limits_enforced_on_increase_take_after_decrease() {
     new_test_ext(1).execute_with(|| {
@@ -3159,6 +3162,9 @@ fn test_rate_limits_enforced_on_increase_take_after_decrease() {
             pallet_subtensor::MaxTake::<Test>::get()
         ));
 
+        // Wait so that we can decrease take
+        step_block(1 + InitialTxDelegateTakeRateLimit::get() as u16);
+
         // Coldkey / hotkey 0 decreases take
         assert_ok!(SubtensorModule::do_decrease_take(
             <<Test as Config>::RuntimeOrigin>::signed(coldkey0),
@@ -3196,6 +3202,69 @@ fn test_rate_limits_enforced_on_increase_take_after_decrease() {
     });
 }
 
+// Test rate-limiting on decrease_take
+#[test]
+fn test_rate_limits_enforced_on_decrease_take() {
+    new_test_ext(1).execute_with(|| {
+        // Make account
+        let hotkey0 = U256::from(1);
+        let coldkey0 = U256::from(3);
+
+        // Add balance
+        SubtensorModule::add_balance_to_coldkey_account(&coldkey0, 100000);
+
+        // Register the neuron to a new network
+        let netuid = 1;
+        add_network(netuid, 0, 0);
+        register_ok_neuron(netuid, hotkey0, coldkey0, 124124);
+
+        // Coldkey / hotkey 0 become delegates with max take
+        assert_ok!(SubtensorModule::do_become_delegate(
+            <<Test as Config>::RuntimeOrigin>::signed(coldkey0),
+            hotkey0,
+            pallet_subtensor::MaxTake::<Test>::get()
+        ));
+
+        // Wait so that we can decrease take first time
+        step_block(1 + InitialTxDelegateTakeRateLimit::get() as u16);
+
+        // Coldkey / hotkey 0 decreases take
+        assert_ok!(SubtensorModule::do_decrease_take(
+            <<Test as Config>::RuntimeOrigin>::signed(coldkey0),
+            hotkey0,
+            SubtensorModule::get_min_take() + 1
+        ));
+
+        // Attempt to immediately decrease again fails due to rate limit
+        assert_eq!(
+            SubtensorModule::do_decrease_take(
+                <<Test as Config>::RuntimeOrigin>::signed(coldkey0),
+                hotkey0,
+                SubtensorModule::get_min_take()
+            ),
+            Err(Error::<Test>::DelegateTxRateLimitExceeded.into())
+        );
+        assert_eq!(
+            SubtensorModule::get_hotkey_take(&hotkey0),
+            SubtensorModule::get_min_take() + 1
+        );
+
+        // After number of blocks, take can be decreased
+        step_block(1 + InitialTxDelegateTakeRateLimit::get() as u16);
+
+        // Can increase after waiting
+        assert_ok!(SubtensorModule::do_decrease_take(
+            <<Test as Config>::RuntimeOrigin>::signed(coldkey0),
+            hotkey0,
+            SubtensorModule::get_min_take()
+        ));
+        assert_eq!(
+            SubtensorModule::get_hotkey_take(&hotkey0),
+            SubtensorModule::get_min_take()
+        );
+    });
+}
+
 // Helper function to set up a test environment
 fn setup_test_environment() -> (AccountId, AccountId, AccountId) {
     let current_coldkey = U256::from(1);