Add tests and modify as_vec implementation (#3715)

* Add tests and modify as_vec implementation

* Address feedback

* fix typo in test

polkadot/node/network/availability-distribution/src/requester/fetch_task/mod.rs

@@ -363,7 +363,7 @@ impl RunningTask {
 
 	fn validate_chunk(&self, validator: &AuthorityDiscoveryId, chunk: &ErasureChunk) -> bool {
 		let anticipated_hash =
-			match branch_hash(&self.erasure_root, &chunk.proof_as_vec(), chunk.index.0 as usize) {
+			match branch_hash(&self.erasure_root, chunk.proof(), chunk.index.0 as usize) {
 				Ok(hash) => hash,
 				Err(e) => {
 					tracing::warn!(

polkadot/node/network/availability-recovery/src/lib.rs

@@ -363,11 +363,9 @@ impl RequestChunksPhase {
 
 					let validator_index = chunk.index;
 
-					if let Ok(anticipated_hash) = branch_hash(
-						&params.erasure_root,
-						&chunk.proof_as_vec(),
-						chunk.index.0 as usize,
-					) {
+					if let Ok(anticipated_hash) =
+						branch_hash(&params.erasure_root, chunk.proof(), chunk.index.0 as usize)
+					{
 						let erasure_chunk_hash = BlakeTwo256::hash(&chunk.chunk);
 
 						if erasure_chunk_hash != anticipated_hash {

polkadot/node/primitives/Cargo.toml

@@ -23,3 +23,6 @@ serde = { version = "1.0.130", features = ["derive"] }
 
 [target.'cfg(not(target_os = "unknown"))'.dependencies]
 zstd = "0.6.0"
+
+[dev-dependencies]
+polkadot-erasure-coding = { path = "../../erasure-coding" }

polkadot/node/primitives/src/lib.rs

@@ -301,8 +301,8 @@ pub struct Proof(BoundedVec<BoundedVec<u8, 1, MERKLE_NODE_MAX_SIZE>, 1, MERKLE_P
 
 impl Proof {
 	/// This function allows to convert back to the standard nested Vec format
-	pub fn as_vec(&self) -> Vec<Vec<u8>> {
-		self.0.as_vec().iter().map(|v| v.as_vec().clone()).collect()
+	pub fn iter(&self) -> impl Iterator<Item = &[u8]> {
+		self.0.iter().map(|v| v.as_slice())
 	}
 
 	/// Construct an invalid dummy proof
@@ -365,7 +365,7 @@ impl Encode for Proof {
 	}
 
 	fn using_encoded<R, F: FnOnce(&[u8]) -> R>(&self, f: F) -> R {
-		let temp = self.as_vec();
+		let temp = self.0.iter().map(|v| v.as_vec()).collect::<Vec<_>>();
 		temp.using_encoded(f)
 	}
 }
@@ -404,8 +404,8 @@ pub struct ErasureChunk {
 
 impl ErasureChunk {
 	/// Convert bounded Vec Proof to regular Vec<Vec<u8>>
-	pub fn proof_as_vec(&self) -> Vec<Vec<u8>> {
-		self.proof.as_vec()
+	pub fn proof(&self) -> &Proof {
+		&self.proof
 	}
 }