Merge pull request #79 from yihuang/optional-last-commit

Represent `last_commit` as `Option<Commit>`

tendermint/src/block.rs

@@ -9,15 +9,15 @@ pub mod parts;
 mod size;
 
 pub use self::{
-    commit::Commit,
-    header::Header,
+    commit::*,
+    header::{parse_non_empty_block_id, Header},
     height::*,
     id::{Id, ParseId},
     meta::Meta,
     size::Size,
 };
 use crate::{abci::transaction, evidence};
-use serde::{Deserialize, Serialize};
+use serde::{Deserialize, Deserializer, Serialize};
 
 /// Blocks consist of a header, transactions, votes (the commit), and a list of
 /// evidence of malfeasance (i.e. signing conflicting votes).
@@ -35,5 +35,28 @@ pub struct Block {
     pub evidence: evidence::Data,
 
     /// Last commit
-    pub last_commit: Commit,
+    #[serde(deserialize_with = "parse_non_empty_commit")]
+    pub last_commit: Option<Commit>,
+}
+
+pub(crate) fn parse_non_empty_commit<'de, D>(deserializer: D) -> Result<Option<Commit>, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    #[derive(Deserialize)]
+    struct TmpCommit {
+        #[serde(deserialize_with = "parse_non_empty_block_id")]
+        block_id: Option<Id>,
+        precommits: Option<Precommits>,
+    }
+
+    let commit = TmpCommit::deserialize(deserializer)?;
+    if commit.block_id.is_none() || commit.precommits.is_none() {
+        Ok(None)
+    } else {
+        Ok(Some(Commit {
+            block_id: commit.block_id.unwrap(),
+            precommits: commit.precommits.unwrap(),
+        }))
+    }
 }

tendermint/src/block/commit.rs

@@ -19,31 +19,31 @@ pub struct Commit {
 
 /// Precommits which certify that a block is valid
 #[derive(Serialize, Deserialize, Clone, Debug)]
-pub struct Precommits(Option<Vec<Option<Vote>>>);
+pub struct Precommits(Vec<Option<Vote>>);
 
 impl Precommits {
     /// Create a new precommit collection
     pub fn new<I>(into_precommits: I) -> Self
     where
         I: Into<Vec<Option<Vote>>>,
     {
-        Self(Some(into_precommits.into()))
+        Self(into_precommits.into())
     }
 
     /// Convert this collection of precommits into a vector
     pub fn into_vec(self) -> Vec<Option<Vote>> {
-        self.iter().cloned().collect()
+        self.0.clone()
     }
 
     /// Iterate over the precommits in the collection
     pub fn iter(&self) -> slice::Iter<'_, Option<Vote>> {
-        self.as_ref().iter()
+        self.0.iter()
     }
 }
 
 impl AsRef<[Option<Vote>]> for Precommits {
     fn as_ref(&self) -> &[Option<Vote>] {
-        self.0.as_ref().map(Vec::as_slice).unwrap_or_else(|| &[])
+        self.0.as_slice()
     }
 }
 

tendermint/src/block/header.rs

@@ -127,19 +127,18 @@ impl lite::Header for Header {
     }
 }
 
-pub(crate) fn parse_non_empty_block_id<'de, D>(
-    deserializer: D,
-) -> Result<Option<block::Id>, D::Error>
+/// Parse empty block id as None.
+pub fn parse_non_empty_block_id<'de, D>(deserializer: D) -> Result<Option<block::Id>, D::Error>
 where
     D: Deserializer<'de>,
 {
-    #[derive(Serialize, Deserialize)]
+    #[derive(Deserialize)]
     struct Parts {
         #[serde(deserialize_with = "serializers::parse_u64")]
         total: u64,
         hash: String,
     }
-    #[derive(Serialize, Deserialize)]
+    #[derive(Deserialize)]
     struct BlockId {
         hash: String,
         parts: Parts,

tendermint/tests/rpc.rs

@@ -51,9 +51,30 @@ mod endpoints {
 
         assert_eq!(data.iter().len(), 2);
         assert_eq!(evidence.iter().len(), 0);
-        assert_eq!(last_commit.precommits.len(), 65);
+        assert_eq!(last_commit.unwrap().precommits.len(), 65);
     }
 
+    #[test]
+    fn first_block() {
+        let response =
+            endpoint::block::Response::from_json(&read_json_fixture("first_block")).unwrap();
+
+        let tendermint::Block {
+            header,
+            data,
+            evidence,
+            last_commit,
+        } = response.block;
+
+        assert_eq!(header.version.block, 10);
+        assert_eq!(header.chain_id.as_str(), EXAMPLE_CHAIN);
+        assert_eq!(header.height.value(), 1);
+        assert!(header.last_block_id.is_none());
+
+        assert_eq!(data.iter().len(), 0);
+        assert_eq!(evidence.iter().len(), 0);
+        assert!(last_commit.is_none());
+    }
     #[test]
     fn block_results() {
         let response =

tendermint/tests/support/rpc/first_block.json

@@ -0,0 +1,87 @@
+{
+  "jsonrpc": "2.0",
+  "id": "",
+  "result": {
+    "block_meta": {
+      "block_id": {
+        "hash": "2638F126FC7ABCBCA071B3EFD7207CB11B8F0518D5209717A31115AA9B1F6A68",
+        "parts": {
+          "total": "1",
+          "hash": "E1ACF6037E216A2C455DBBAE23C266ECA07C7F5540CAE9383146D7B20E5CA24D"
+        }
+      },
+      "header": {
+        "version": {
+          "block": "10",
+          "app": "0"
+        },
+        "chain_id": "cosmoshub-1",
+        "height": "1",
+        "time": "2019-11-20T08:56:48.618137Z",
+        "num_txs": "0",
+        "total_txs": "0",
+        "last_block_id": {
+          "hash": "",
+          "parts": {
+            "total": "0",
+            "hash": ""
+          }
+        },
+        "last_commit_hash": "",
+        "data_hash": "",
+        "validators_hash": "2ADC39A2BA237647FD3D6524739F0952F7AC8BBC895F120403DD4EAA8DCF248A",
+        "next_validators_hash": "2ADC39A2BA237647FD3D6524739F0952F7AC8BBC895F120403DD4EAA8DCF248A",
+        "consensus_hash": "048091BC7DDC283F77BFBF91D73C44DA58C3DF8A9CBC867405D8B7F3DAADA22F",
+        "app_hash": "E0ADD6C9D9C3520D5D5242E2B33FA259FB75B7E2F59C0A2E40FF2493F6C72050",
+        "last_results_hash": "",
+        "evidence_hash": "",
+        "proposer_address": "B84241A54F45F970C173811AF184803264140906"
+      }
+    },
+    "block": {
+      "header": {
+        "version": {
+          "block": "10",
+          "app": "0"
+        },
+        "chain_id": "cosmoshub-1",
+        "height": "1",
+        "time": "2019-11-20T08:56:48.618137Z",
+        "num_txs": "0",
+        "total_txs": "0",
+        "last_block_id": {
+          "hash": "",
+          "parts": {
+            "total": "0",
+            "hash": ""
+          }
+        },
+        "last_commit_hash": "",
+        "data_hash": "",
+        "validators_hash": "2ADC39A2BA237647FD3D6524739F0952F7AC8BBC895F120403DD4EAA8DCF248A",
+        "next_validators_hash": "2ADC39A2BA237647FD3D6524739F0952F7AC8BBC895F120403DD4EAA8DCF248A",
+        "consensus_hash": "048091BC7DDC283F77BFBF91D73C44DA58C3DF8A9CBC867405D8B7F3DAADA22F",
+        "app_hash": "E0ADD6C9D9C3520D5D5242E2B33FA259FB75B7E2F59C0A2E40FF2493F6C72050",
+        "last_results_hash": "",
+        "evidence_hash": "",
+        "proposer_address": "B84241A54F45F970C173811AF184803264140906"
+      },
+      "data": {
+        "txs": null
+      },
+      "evidence": {
+        "evidence": null
+      },
+      "last_commit": {
+        "block_id": {
+          "hash": "",
+          "parts": {
+            "total": "0",
+            "hash": ""
+          }
+        },
+        "precommits": null
+      }
+    }
+  }
+}