feat(contract): add helper to query events w/ metadata (block num + tx hash) (#33)

* feat(contract): add helper to query events w/ metadata (block num + tx hash)

ethers-contract/src/event.rs

@@ -4,13 +4,14 @@ use ethers_providers::{FilterStream, JsonRpcClient, Provider};
 
 use ethers_core::{
     abi::{Detokenize, Event as AbiEvent, RawLog},
-    types::{BlockNumber, Filter, Log, ValueOrArray, H256},
+    types::{BlockNumber, Filter, Log, TxHash, ValueOrArray, H256, U64},
 };
 
 use futures::stream::{Stream, StreamExt};
-use std::{collections::HashMap, marker::PhantomData};
+use std::marker::PhantomData;
 
 /// Helper for managing the event filter before querying or streaming its logs
+#[derive(Debug)]
 #[must_use = "event filters do nothing unless you `query` or `stream` them"]
 pub struct Event<'a: 'b, 'b, P, D> {
     /// The event filter's state
@@ -93,16 +94,16 @@ where
         Ok(events)
     }
 
-    /// Queries the blockchain for the selected filter and returns a hashmap of
-    /// txhash -> logs
-    pub async fn query_with_hashes(&self) -> Result<HashMap<H256, D>, ContractError> {
+    /// Queries the blockchain for the selected filter and returns a vector of logs
+    /// along with their metadata
+    pub async fn query_with_meta(&self) -> Result<Vec<(D, LogMeta)>, ContractError> {
         let logs = self.provider.get_logs(&self.filter).await?;
         let events = logs
             .into_iter()
             .map(|log| {
-                let tx_hash = log.transaction_hash.expect("should have tx hash");
+                let meta = LogMeta::from(&log);
                 let event = self.parse_log(log)?;
-                Ok((tx_hash, event))
+                Ok((event, meta))
             })
             .collect::<Result<_, ContractError>>()?;
         Ok(events)
@@ -125,3 +126,22 @@ where
         Ok(D::from_tokens(tokens)?)
     }
 }
+
+/// Metadata inside a log
+#[derive(Clone, Debug, PartialEq)]
+pub struct LogMeta {
+    /// The block in which the log was emitted
+    pub block_number: U64,
+
+    /// The transaction hash in which the log was emitted
+    pub transaction_hash: TxHash,
+}
+
+impl From<&Log> for LogMeta {
+    fn from(src: &Log) -> Self {
+        LogMeta {
+            block_number: src.block_number.expect("should have a block number"),
+            transaction_hash: src.transaction_hash.expect("should have a tx hash"),
+        }
+    }
+}

ethers-contract/src/factory.rs

@@ -2,7 +2,7 @@ use crate::{Contract, ContractError};
 
 use ethers_core::{
     abi::{Abi, Tokenize},
-    types::{Bytes, TransactionRequest},
+    types::{BlockNumber, Bytes, TransactionRequest},
 };
 use ethers_providers::JsonRpcClient;
 use ethers_signers::{Client, Signer};
@@ -15,6 +15,7 @@ pub struct Deployer<'a, P, S> {
     abi: Abi,
     client: &'a Client<P, S>,
     confs: usize,
+    block: BlockNumber,
 }
 
 impl<'a, P, S> Deployer<'a, P, S>
@@ -28,11 +29,19 @@ where
         self
     }
 
+    pub fn block<T: Into<BlockNumber>>(mut self, block: T) -> Self {
+        self.block = block.into();
+        self
+    }
+
     /// Broadcasts the contract deployment transaction and after waiting for it to
     /// be sufficiently confirmed (default: 1), it returns a [`Contract`](crate::Contract)
     /// struct at the deployed contract's address.
     pub async fn send(self) -> Result<Contract<'a, P, S>, ContractError> {
-        let pending_tx = self.client.send_transaction(self.tx, None).await?;
+        let pending_tx = self
+            .client
+            .send_transaction(self.tx, Some(self.block))
+            .await?;
 
         let receipt = pending_tx.confirmations(self.confs).await?;
 
@@ -159,6 +168,7 @@ where
             abi: self.abi,
             tx,
             confs: 1,
+            block: BlockNumber::Latest,
         })
     }
 }

ethers-contract/tests/contract.rs

@@ -176,6 +176,7 @@ mod celo_tests {
     use ethers::{
         providers::{Http, Provider},
         signers::Wallet,
+        types::BlockNumber,
     };
     use std::convert::TryFrom;
 
@@ -195,7 +196,7 @@ mod celo_tests {
 
         let factory = ContractFactory::new(abi, bytecode, &client);
         let deployer = factory.deploy("initial value".to_string()).unwrap();
-        let contract = deployer.send().await.unwrap();
+        let contract = deployer.block(BlockNumber::Pending).send().await.unwrap();
 
         let value: String = contract
             .method("getValue", ())