fix(BREAKING): return Option for txs/receipts/blocks (#64)

* fix(BREAKING): return Option for txs/receipts/blocks

Otherwise if a user asks for a transaction hash or block that does not exist yet they'll get an Error

* test: ensure that unmined txs return None receipts

* test: fix remaining tests

* chore: re-enable sparkpool gas oracle

* chore: fix celo tests

* fix: run the non-existing data against infura

* fix: fix etherscan gas oracle tests

ethers-contract/tests/contract.rs

@@ -53,8 +53,12 @@ mod eth_tests {
         let calldata = contract_call.calldata().unwrap();
         let gas_estimate = contract_call.estimate_gas().await.unwrap();
         let tx_hash = contract_call.send().await.unwrap();
-        let tx = client.get_transaction(tx_hash).await.unwrap();
-        let tx_receipt = client.get_transaction_receipt(tx_hash).await.unwrap();
+        let tx = client.get_transaction(tx_hash).await.unwrap().unwrap();
+        let tx_receipt = client
+            .get_transaction_receipt(tx_hash)
+            .await
+            .unwrap()
+            .unwrap();
         assert_eq!(last_sender.clone().call().await.unwrap(), client2.address());
         assert_eq!(get_value.clone().call().await.unwrap(), "hi");
         assert_eq!(tx.input, calldata);

ethers-providers/src/gas_oracle/etherscan.rs

@@ -33,10 +33,13 @@ struct EtherscanResponseInner {
     #[serde(deserialize_with = "deserialize_number_from_string")]
     #[serde(rename = "ProposeGasPrice")]
     propose_gas_price: u64,
+    #[serde(deserialize_with = "deserialize_number_from_string")]
+    #[serde(rename = "FastGasPrice")]
+    fast_gas_price: u64,
 }
 
 impl Etherscan {
-    pub fn new(api_key: Option<&'static str>) -> Self {
+    pub fn new(api_key: Option<&str>) -> Self {
         let url = match api_key {
             Some(key) => format!("{}&apikey={}", ETHERSCAN_URL_PREFIX, key),
             None => ETHERSCAN_URL_PREFIX.to_string(),
@@ -60,7 +63,7 @@ impl Etherscan {
 #[async_trait]
 impl GasOracle for Etherscan {
     async fn fetch(&self) -> Result<U256, GasOracleError> {
-        if matches!(self.gas_category, GasCategory::Fast | GasCategory::Fastest) {
+        if matches!(self.gas_category, GasCategory::Fastest) {
             return Err(GasOracleError::GasCategoryNotSupported);
         }
 
@@ -75,6 +78,7 @@ impl GasOracle for Etherscan {
         match self.gas_category {
             GasCategory::SafeLow => Ok(U256::from(res.result.safe_gas_price * GWEI_TO_WEI)),
             GasCategory::Standard => Ok(U256::from(res.result.propose_gas_price * GWEI_TO_WEI)),
+            GasCategory::Fast => Ok(U256::from(res.result.fast_gas_price * GWEI_TO_WEI)),
             _ => Err(GasOracleError::GasCategoryNotSupported),
         }
     }

ethers-providers/src/pending_transaction.rs

@@ -73,7 +73,11 @@ impl<'a, P: JsonRpcClient> Future for PendingTransaction<'a, P> {
             }
             PendingTxState::GettingReceipt(fut) => {
                 if let Ok(receipt) = futures_util::ready!(fut.as_mut().poll(ctx)) {
-                    *this.state = PendingTxState::CheckingReceipt(Box::new(receipt))
+                    if let Some(receipt) = receipt {
+                        *this.state = PendingTxState::CheckingReceipt(Box::new(receipt))
+                    } else {
+                        *this.state = PendingTxState::PausedGettingReceipt
+                    }
                 } else {
                     *this.state = PendingTxState::PausedGettingReceipt
                 }
@@ -173,7 +177,7 @@ enum PendingTxState<'a> {
     PausedGettingReceipt,
 
     /// Polling the blockchain for the receipt
-    GettingReceipt(PinBoxFut<'a, TransactionReceipt>),
+    GettingReceipt(PinBoxFut<'a, Option<TransactionReceipt>>),
 
     /// Waiting for interval to elapse before calling API again
     PausedGettingBlockNumber(Box<TransactionReceipt>),

ethers-providers/src/provider.rs

@@ -92,7 +92,7 @@ impl<P: JsonRpcClient> Provider<P> {
     pub async fn get_block(
         &self,
         block_hash_or_number: impl Into<BlockId>,
-    ) -> Result<Block<TxHash>, ProviderError> {
+    ) -> Result<Option<Block<TxHash>>, ProviderError> {
         Ok(self
             .get_block_gen(block_hash_or_number.into(), false)
             .await?)
@@ -102,7 +102,7 @@ impl<P: JsonRpcClient> Provider<P> {
     pub async fn get_block_with_txs(
         &self,
         block_hash_or_number: impl Into<BlockId>,
-    ) -> Result<Block<Transaction>, ProviderError> {
+    ) -> Result<Option<Block<Transaction>>, ProviderError> {
         Ok(self
             .get_block_gen(block_hash_or_number.into(), true)
             .await?)
@@ -112,7 +112,7 @@ impl<P: JsonRpcClient> Provider<P> {
         &self,
         id: BlockId,
         include_txs: bool,
-    ) -> Result<Block<Tx>, ProviderError> {
+    ) -> Result<Option<Block<Tx>>, ProviderError> {
         let include_txs = utils::serialize(&include_txs);
 
         Ok(match id {
@@ -137,7 +137,7 @@ impl<P: JsonRpcClient> Provider<P> {
     pub async fn get_transaction<T: Send + Sync + Into<TxHash>>(
         &self,
         transaction_hash: T,
-    ) -> Result<Transaction, ProviderError> {
+    ) -> Result<Option<Transaction>, ProviderError> {
         let hash = transaction_hash.into();
         Ok(self
             .0
@@ -150,7 +150,7 @@ impl<P: JsonRpcClient> Provider<P> {
     pub async fn get_transaction_receipt<T: Send + Sync + Into<TxHash>>(
         &self,
         transaction_hash: T,
-    ) -> Result<TransactionReceipt, ProviderError> {
+    ) -> Result<Option<TransactionReceipt>, ProviderError> {
         let hash = transaction_hash.into();
         Ok(self
             .0
@@ -614,6 +614,7 @@ mod ens_tests {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::Http;
     use ethers_core::types::H256;
     use futures_util::StreamExt;
 
@@ -636,6 +637,7 @@ mod tests {
             let block = provider
                 .get_block(start_block + i as u64 + 1)
                 .await
+                .unwrap()
                 .unwrap();
             assert_eq!(*hash, block.hash.unwrap());
         }
@@ -673,4 +675,33 @@ mod tests {
         let hashes: Vec<H256> = stream.take(num_txs).collect::<Vec<H256>>().await;
         assert_eq!(tx_hashes, hashes);
     }
+
+    #[tokio::test]
+    async fn receipt_on_unmined_tx() {
+        use ethers_core::{
+            types::TransactionRequest,
+            utils::{parse_ether, Ganache},
+        };
+        let ganache = Ganache::new().block_time(2u64).spawn();
+        let provider = Provider::<Http>::try_from(ganache.endpoint()).unwrap();
+
+        let accounts = provider.get_accounts().await.unwrap();
+        let tx = TransactionRequest::pay(accounts[0], parse_ether(1u64).unwrap()).from(accounts[0]);
+        let tx_hash = provider.send_transaction(tx).await.unwrap();
+
+        assert!(provider
+            .get_transaction_receipt(tx_hash)
+            .await
+            .unwrap()
+            .is_none());
+
+        // couple of seconds pass
+        std::thread::sleep(std::time::Duration::new(3, 0));
+
+        assert!(provider
+            .get_transaction_receipt(tx_hash)
+            .await
+            .unwrap()
+            .is_some());
+    }
 }

ethers-providers/tests/provider.rs

@@ -10,10 +10,39 @@ mod eth_tests {
     use super::*;
     use ethers::{
         providers::JsonRpcClient,
-        types::TransactionRequest,
+        types::{BlockId, TransactionRequest, H256},
         utils::{parse_ether, Ganache},
     };
 
+    #[tokio::test]
+    async fn non_existing_data_works() {
+        let provider = Provider::<Http>::try_from(
+            "https://rinkeby.infura.io/v3/c60b0bb42f8a4c6481ecd229eddaca27",
+        )
+        .unwrap();
+
+        assert!(provider
+            .get_transaction(H256::zero())
+            .await
+            .unwrap()
+            .is_none());
+        assert!(provider
+            .get_transaction_receipt(H256::zero())
+            .await
+            .unwrap()
+            .is_none());
+        assert!(provider
+            .get_block(BlockId::Hash(H256::zero()))
+            .await
+            .unwrap()
+            .is_none());
+        assert!(provider
+            .get_block_with_txs(BlockId::Hash(H256::zero()))
+            .await
+            .unwrap()
+            .is_none());
+    }
+
     // Without TLS this would error with "TLS Support not compiled in"
     #[test]
     #[cfg(any(feature = "async-std-tls", feature = "tokio-tls"))]
@@ -83,14 +112,17 @@ mod eth_tests {
         let data_1 = eth_gas_station_oracle.fetch().await;
         assert!(data_1.is_ok());
 
+        let api_key = std::env::var("ETHERSCAN_API_KEY").unwrap();
+        let api_key = Some(api_key.as_str());
+
         // initialize and fetch gas estimates from Etherscan
         // since etherscan does not support `fastest` category, we expect an error
-        let etherscan_oracle = Etherscan::new(None).category(GasCategory::Fastest);
+        let etherscan_oracle = Etherscan::new(api_key).category(GasCategory::Fastest);
         let data_2 = etherscan_oracle.fetch().await;
         assert!(data_2.is_err());
 
         // but fetching the `standard` gas price should work fine
-        let etherscan_oracle_2 = Etherscan::new(None).category(GasCategory::SafeLow);
+        let etherscan_oracle_2 = Etherscan::new(api_key).category(GasCategory::SafeLow);
 
         let data_3 = etherscan_oracle_2.fetch().await;
         assert!(data_3.is_ok());
@@ -100,12 +132,10 @@ mod eth_tests {
         let data_4 = etherchain_oracle.fetch().await;
         assert!(data_4.is_ok());
 
-        // TODO: Temporarily disabled SparkPool's GasOracle while the API is still
-        // evolving.
-        // // initialize and fetch gas estimates from SparkPool
-        // let gas_now_oracle = GasNow::new().category(GasCategory::Fastest);
-        // let data_5 = gas_now_oracle.fetch().await;
-        // assert!(data_5.is_ok());
+        // initialize and fetch gas estimates from SparkPool
+        let gas_now_oracle = GasNow::new().category(GasCategory::Fastest);
+        let data_5 = gas_now_oracle.fetch().await;
+        assert!(data_5.is_ok());
     }
 
     async fn generic_pending_txs_test<P: JsonRpcClient>(provider: Provider<P>) {
@@ -140,7 +170,7 @@ mod celo_tests {
         let tx_hash = "c8496681d0ade783322980cce00c89419fce4b484635d9e09c79787a0f75d450"
             .parse::<H256>()
             .unwrap();
-        let tx = provider.get_transaction(tx_hash).await.unwrap();
+        let tx = provider.get_transaction(tx_hash).await.unwrap().unwrap();
         assert!(tx.gateway_fee_recipient.is_none());
         assert_eq!(tx.gateway_fee.unwrap(), 0.into());
         assert_eq!(tx.hash, tx_hash);
@@ -152,7 +182,7 @@ mod celo_tests {
         let provider =
             Provider::<Http>::try_from("https://alfajores-forno.celo-testnet.org").unwrap();
 
-        let block = provider.get_block(447254).await.unwrap();
+        let block = provider.get_block(447254).await.unwrap().unwrap();
         assert_eq!(
             block.randomness,
             Randomness {

ethers-signers/tests/signer.rs

@@ -114,6 +114,7 @@ mod eth_tests {
                     .get_transaction(tx_hash)
                     .await
                     .unwrap()
+                    .unwrap()
                     .nonce
                     .as_u64(),
             );
@@ -148,7 +149,7 @@ mod eth_tests {
         let tx = TransactionRequest::new().to(wallet2.address()).value(10000);
         let tx_hash = client.send_transaction(tx, None).await.unwrap();
 
-        let tx = client.get_transaction(tx_hash).await.unwrap();
+        let tx = client.get_transaction(tx_hash).await.unwrap().unwrap();
         assert_eq!(tx.gas_price, expected_gas_price);
     }
 }