From c8a35e60f77ace0c167232149e6c1fdd14b29ed2 Mon Sep 17 00:00:00 2001
From: arya2 <aryasolhi@gmail.com>
Date: Tue, 10 Jan 2023 12:57:41 -0500
Subject: [PATCH] Applies cleanup suggestions from code review

---
 .../methods/get_block_template_rpcs/constants.rs |  5 +++++
 zebra-state/src/service.rs                       | 16 ++++++++--------
 zebra-state/src/service/check.rs                 |  4 ++--
 zebra-state/src/service/write.rs                 |  4 +---
 4 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/zebra-rpc/src/methods/get_block_template_rpcs/constants.rs b/zebra-rpc/src/methods/get_block_template_rpcs/constants.rs
index 2c0e7814e44..712be0066e8 100644
--- a/zebra-rpc/src/methods/get_block_template_rpcs/constants.rs
+++ b/zebra-rpc/src/methods/get_block_template_rpcs/constants.rs
@@ -26,6 +26,11 @@ pub const GET_BLOCK_TEMPLATE_MUTABLE_FIELD: &[&str] = &[
 ];
 
 /// A hardcoded list of Zebra's getblocktemplate RPC capabilities.
+///
+/// See:
+/// - <https://en.bitcoin.it/wiki/BIP_0023#Mutations>
+/// - <https://en.bitcoin.it/wiki/BIP_0023#Block_Proposal>
+/// - <https://zips.z.cash/protocol/protocol.pdf#blockheader>
 pub const GET_BLOCK_TEMPLATE_CAPABILITIES_FIELD: &[&str] = &["proposal"];
 
 /// The max estimated distance to the chain tip for the getblocktemplate method.
diff --git a/zebra-state/src/service.rs b/zebra-state/src/service.rs
index 5ed7f1e9d34..b8638520dec 100644
--- a/zebra-state/src/service.rs
+++ b/zebra-state/src/service.rs
@@ -1718,14 +1718,14 @@ impl Service<ReadRequest> for ReadStateService {
                         tracing::info!("attempting to validate and commit block proposal onto a cloned non-finalized state");
                         let mut latest_non_finalized_state = state.latest_non_finalized_state();
 
-                       // The previous block of a valid proposal must be on the best chain tip.
-                       let Some((_best_tip_height, best_tip_hash) = read::best_tip(&latest_non_finalized_state, &state.db) {
-                           if prepared.block.header.previous_block_hash !=  best_tip_hash {
-                               return Err("proposal is not based on the current best chain tip: previous block hash must be the best chain tip".into());
-                           }
-                       } else {
-                           return Err("state is empty: wait for Zebra to sync before submitting a proposal".into());
-                       }
+                        // The previous block of a valid proposal must be on the best chain tip.
+                        let Some((_best_tip_height, best_tip_hash)) = read::best_tip(&latest_non_finalized_state, &state.db) else {
+                            return Err("state is empty: wait for Zebra to sync before submitting a proposal".into());
+                        };
+
+                        if prepared.block.header.previous_block_hash != best_tip_hash {
+                            return Err("proposal is not based on the current best chain tip: previous block hash must be the best chain tip".into());
+                        }
 
                         // This clone of the non-finalized state is dropped when this closure returns.
                         // The non-finalized state that's used in the rest of the state (including finalizing
diff --git a/zebra-state/src/service/check.rs b/zebra-state/src/service/check.rs
index 603eb4f3e8d..0b3600ad89b 100644
--- a/zebra-state/src/service/check.rs
+++ b/zebra-state/src/service/check.rs
@@ -14,13 +14,13 @@ use zebra_chain::{
 use crate::{
     service::{
         block_iter::any_ancestor_blocks, check::difficulty::POW_ADJUSTMENT_BLOCK_SPAN,
-        non_finalized_state::NonFinalizedState,
+        finalized_state::ZebraDb, non_finalized_state::NonFinalizedState,
     },
     BoxError, PreparedBlock, ValidateContextError,
 };
 
 // use self as check
-use super::{check, finalized_state::ZebraDb};
+use super::check;
 
 // These types are used in doc links
 #[allow(unused_imports)]
diff --git a/zebra-state/src/service/write.rs b/zebra-state/src/service/write.rs
index 7b91c09227c..8f33af7b6d1 100644
--- a/zebra-state/src/service/write.rs
+++ b/zebra-state/src/service/write.rs
@@ -12,7 +12,7 @@ use crate::{
     constants::MAX_BLOCK_REORG_HEIGHT,
     service::{
         check,
-        finalized_state::FinalizedState,
+        finalized_state::{FinalizedState, ZebraDb},
         non_finalized_state::NonFinalizedState,
         queued_blocks::{QueuedFinalized, QueuedNonFinalized},
         BoxError, ChainTipBlock, ChainTipSender, CloneError,
@@ -27,8 +27,6 @@ use crate::service::{
     non_finalized_state::Chain,
 };
 
-use super::finalized_state::ZebraDb;
-
 /// The maximum size of the parent error map.
 ///
 /// We allow enough space for multiple concurrent chain forks with errors.