Directory Restructure (#1163)

* Move tests -> testing

* Directory restructure

* Update Cargo.toml during restructure

* Update Makefile during restructure

* Fix arbitrary path

consensus/state_processing/src/per_epoch_processing/process_slashings.rs

@@ -0,0 +1,35 @@
+use safe_arith::SafeArith;
+use types::{BeaconStateError as Error, *};
+
+/// Process slashings.
+///
+/// Spec v0.11.1
+pub fn process_slashings<T: EthSpec>(
+    state: &mut BeaconState<T>,
+    total_balance: u64,
+    spec: &ChainSpec,
+) -> Result<(), Error> {
+    let epoch = state.current_epoch();
+    let sum_slashings = state.get_all_slashings().iter().sum::<u64>();
+
+    for (index, validator) in state.validators.iter().enumerate() {
+        if validator.slashed
+            && epoch + T::EpochsPerSlashingsVector::to_u64().safe_div(2)?
+                == validator.withdrawable_epoch
+        {
+            let increment = spec.effective_balance_increment;
+            let penalty_numerator = validator
+                .effective_balance
+                .safe_div(increment)?
+                .safe_mul(std::cmp::min(sum_slashings.safe_mul(3)?, total_balance))?;
+            let penalty = penalty_numerator
+                .safe_div(total_balance)?
+                .safe_mul(increment)?;
+
+            // Equivalent to `decrease_balance(state, index, penalty)`, but avoids borrowing `state`.
+            state.balances[index] = state.balances[index].saturating_sub(penalty);
+        }
+    }
+
+    Ok(())
+}