chore(clippy): Cleanup nightly clippy warnings from 2023-10-30 (#7868)

* Use first() rather than get(0)

* Remove unused imports and silence test-related warnings

* More clippy fixes

zebra-chain/src/orchard/tests/vectors.rs

@@ -4,6 +4,6 @@ mod sinsemilla;
 mod tree;
 
 pub use group_hash::GROUP_HASHES;
-pub use key_components::KEY_COMPONENTS;
+
 pub use sinsemilla::SINSEMILLA;
 pub use tree::{COMMITMENTS, EMPTY_ROOTS, ROOTS};

zebra-consensus/src/block/check.rs

@@ -33,7 +33,7 @@ pub fn coinbase_is_first(block: &Block) -> Result<Arc<transaction::Transaction>,
     // <https://zips.z.cash/protocol/protocol.pdf#blockheader>
     let first = block
         .transactions
-        .get(0)
+        .first()
         .ok_or(BlockError::NoTransactions)?;
     // > The first transaction in a block MUST be a coinbase transaction,
     // > and subsequent transactions MUST NOT be coinbase transactions.
@@ -142,7 +142,7 @@ pub fn equihash_solution_is_valid(header: &Header) -> Result<(), equihash::Error
 /// [3.9]: https://zips.z.cash/protocol/protocol.pdf#subsidyconcepts
 pub fn subsidy_is_valid(block: &Block, network: Network) -> Result<(), BlockError> {
     let height = block.coinbase_height().ok_or(SubsidyError::NoCoinbase)?;
-    let coinbase = block.transactions.get(0).ok_or(SubsidyError::NoCoinbase)?;
+    let coinbase = block.transactions.first().ok_or(SubsidyError::NoCoinbase)?;
 
     // Validate funding streams
     let Some(halving_div) = subsidy::general::halving_divisor(height, network) else {
@@ -211,7 +211,7 @@ pub fn miner_fees_are_valid(
     block_miner_fees: Amount<NonNegative>,
 ) -> Result<(), BlockError> {
     let height = block.coinbase_height().ok_or(SubsidyError::NoCoinbase)?;
-    let coinbase = block.transactions.get(0).ok_or(SubsidyError::NoCoinbase)?;
+    let coinbase = block.transactions.first().ok_or(SubsidyError::NoCoinbase)?;
 
     let transparent_value_balance: Amount = subsidy::general::output_amounts(coinbase)
         .iter()

zebra-consensus/src/block/tests.rs

@@ -103,7 +103,7 @@ static INVALID_COINBASE_TRANSCRIPT: Lazy<
     assert_eq!(block3.transactions.len(), 1);
 
     // Extract the coinbase transaction from the block
-    let coinbase_transaction = block3.transactions.get(0).unwrap().clone();
+    let coinbase_transaction = block3.transactions.first().unwrap().clone();
 
     // Add another coinbase transaction to block
     block3.transactions.push(coinbase_transaction);
@@ -373,7 +373,7 @@ fn coinbase_validation_failure() -> Result<(), Report> {
     block.transactions.push(
         block
             .transactions
-            .get(0)
+            .first()
             .expect("block has coinbase")
             .clone(),
     );
@@ -436,7 +436,7 @@ fn funding_stream_validation_failure() -> Result<(), Report> {
     // Build the new transaction with modified coinbase outputs
     let tx = block
         .transactions
-        .get(0)
+        .first()
         .map(|transaction| {
             let mut output = transaction.outputs()[0].clone();
             output.value = Amount::try_from(i32::MAX).unwrap();

zebra-consensus/src/transaction/tests.rs

@@ -2791,7 +2791,7 @@ fn coinbase_outputs_are_decryptable_for_historical_blocks_for_network(
                 .unwrap();
         let coinbase_tx = block
             .transactions
-            .get(0)
+            .first()
             .expect("must have coinbase transaction");
 
         // Check if the coinbase outputs are decryptable with an all-zero key.

zebra-state/src/service/check.rs

@@ -72,7 +72,7 @@ where
         .collect();
 
     let parent_block = relevant_chain
-        .get(0)
+        .first()
         .expect("state must contain parent block to do contextual validation");
     let parent_block = parent_block.borrow();
     let parent_height = parent_block

zebra-state/src/service/finalized_state/disk_format.rs

@@ -16,7 +16,7 @@ pub mod upgrade;
 #[cfg(test)]
 mod tests;
 
-pub use block::{TransactionIndex, TransactionLocation, MAX_ON_DISK_HEIGHT};
+pub use block::{TransactionLocation, MAX_ON_DISK_HEIGHT};
 pub use transparent::{OutputIndex, OutputLocation};
 
 /// Helper type for writing types to disk as raw bytes.

zebra-state/src/service/read.rs

@@ -28,21 +28,21 @@ mod tests;
 pub use address::{
     balance::transparent_balance,
     tx_id::transparent_tx_ids,
-    utxo::{address_utxos, AddressUtxos, ADDRESS_HEIGHTS_FULL_RANGE},
+    utxo::{address_utxos, AddressUtxos},
 };
 pub use block::{
     any_utxo, block, block_header, mined_transaction, transaction_hashes_for_block, unspent_utxo,
-    utxo,
 };
 pub use find::{
-    best_tip, block_locator, chain_contains_hash, depth, finalized_state_contains_block_hash,
-    find_chain_hashes, find_chain_headers, hash_by_height, height_by_hash, next_median_time_past,
+    best_tip, block_locator, depth, finalized_state_contains_block_hash, find_chain_hashes,
+    find_chain_headers, hash_by_height, height_by_hash, next_median_time_past,
     non_finalized_state_contains_block_hash, tip, tip_height,
 };
 pub use tree::{orchard_subtrees, orchard_tree, sapling_subtrees, sapling_tree};
 
-#[cfg(feature = "getblocktemplate-rpcs")]
-pub use difficulty::get_block_template_chain_info;
+#[cfg(any(test, feature = "proptest-impl"))]
+#[allow(unused_imports)]
+pub use address::utxo::ADDRESS_HEIGHTS_FULL_RANGE;
 
 /// If a finalized state query is interrupted by a new finalized block,
 /// retry this many times.

zebra-state/src/service/tests.rs

@@ -143,20 +143,20 @@ async fn test_populated_state_responds_correctly(
             transcript.push((
                 Request::FindBlockHashes {
                     known_blocks: known_hashes.iter().rev().cloned().collect(),
-                    stop: next_hashes.get(0).cloned(),
+                    stop: next_hashes.first().cloned(),
                 },
                 Ok(Response::BlockHashes(
-                    next_hashes.get(0).iter().cloned().cloned().collect(),
+                    next_hashes.first().iter().cloned().cloned().collect(),
                 )),
             ));
 
             transcript.push((
                 Request::FindBlockHeaders {
                     known_blocks: known_hashes.iter().rev().cloned().collect(),
-                    stop: next_hashes.get(0).cloned(),
+                    stop: next_hashes.first().cloned(),
                 },
                 Ok(Response::BlockHeaders(
-                    next_headers.get(0).iter().cloned().cloned().collect(),
+                    next_headers.first().iter().cloned().cloned().collect(),
                 )),
             ));