feat(cast): implement cast receipt (gakonst#535)

* feat(cast): implement `cast receipt`

This commit implements `cast receipt`. If the receipt is not
found, it will poll until it is found. Similar to `seth`,
an optional field can be passed to only print a particular
field on the receipt response. Unlike `seth`, there is a
`--json/-j` flag that will render the receipt as JSON.

Example usage:

```bash
cast receipt --rpc-url https://mainnet.optimism.io \
    0xa9fc1761ecad57693d7000b7bd8aea8ae5c3c34a1fcf966097778068c82c86cc
```

* fix: use PendingTx to poll for a tx's receipt

Co-authored-by: Georgios Konstantopoulos <[email protected]>

cast/README.md

@@ -50,7 +50,7 @@
 - [x] `namehash`
 - [x] `nonce`
 - [x] `publish`
-- [ ] `receipt`
+- [x] `receipt`
 - [x] `resolve-name`
 - [ ] `run-tx`
 - [x] `send` (partial)

cast/src/lib.rs

@@ -522,6 +522,66 @@ where
             if to_json { serde_json::to_string(&transaction)? } else { to_table(transaction) };
         Ok(transaction)
     }
+
+    /// ```no_run
+    /// use cast::Cast;
+    /// use ethers_providers::{Provider, Http};
+    /// use std::convert::TryFrom;
+    ///
+    /// # async fn foo() -> eyre::Result<()> {
+    /// let provider = Provider::<Http>::try_from("http://localhost:8545")?;
+    /// let cast = Cast::new(provider);
+    /// let tx_hash = "0xf8d1713ea15a81482958fb7ddf884baee8d3bcc478c5f2f604e008dc788ee4fc";
+    /// let receipt = cast.receipt(tx_hash.to_string(), None, 1, false, false).await?;
+    /// println!("{}", receipt);
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub async fn receipt(
+        &self,
+        tx_hash: String,
+        field: Option<String>,
+        confs: usize,
+        cast_async: bool,
+        to_json: bool,
+    ) -> Result<String> {
+        let tx_hash = H256::from_str(&tx_hash)?;
+
+        // try to get the receipt
+        let receipt = self.provider.get_transaction_receipt(tx_hash).await?;
+
+        // if the async flag is provided, immediately exit if no tx is found,
+        // otherwise try to poll for it
+        let receipt = if cast_async {
+            match receipt {
+                Some(inner) => inner,
+                None => return Ok("receipt not found".to_string()),
+            }
+        } else {
+            match receipt {
+                Some(inner) => inner,
+                None => {
+                    let tx = PendingTransaction::new(tx_hash, self.provider.provider());
+                    match tx.confirmations(confs).await? {
+                        Some(inner) => inner,
+                        None => return Ok("receipt not found when polling pending tx. was the transaction dropped from the mempool?".to_string())
+                    }
+                }
+            }
+        };
+
+        let receipt = if let Some(ref field) = field {
+            serde_json::to_value(&receipt)?
+                .get(field)
+                .cloned()
+                .ok_or_else(|| eyre::eyre!("field {} not found", field))?
+        } else {
+            serde_json::to_value(&receipt)?
+        };
+
+        let receipt = if to_json { serde_json::to_string(&receipt)? } else { to_table(receipt) };
+        Ok(receipt)
+    }
 }
 
 pub struct InterfaceSource {

cli/src/cast.rs

@@ -418,6 +418,15 @@ async fn main() -> eyre::Result<()> {
             let value = provider.get_storage_at(address, slot, block).await?;
             println!("{:?}", value);
         }
+        Subcommands::Receipt { hash, field, to_json, rpc_url, cast_async, confirmations } => {
+            let provider = Provider::try_from(rpc_url)?;
+            println!(
+                "{}",
+                Cast::new(provider)
+                    .receipt(hash, field, confirmations, cast_async, to_json)
+                    .await?
+            );
+        }
         Subcommands::Nonce { block, who, rpc_url } => {
             let provider = Provider::try_from(rpc_url)?;
             println!("{}", Cast::new(provider).nonce(who, block).await?);

cli/src/opts/cast.rs

@@ -59,8 +59,8 @@ pub enum Subcommands {
     ToUint256 { value: Option<String> },
     #[clap(name = "--to-unit")]
     #[clap(
-        about = r#"convert an ETH amount into a specified unit: ether, gwei or wei (default: wei). 
-    Usage: 
+        about = r#"convert an ETH amount into a specified unit: ether, gwei or wei (default: wei).
+    Usage:
       - 1ether wei     | converts 1 ether to wei
       - "1 ether" wei  | converts 1 ether to wei
       - 1ether         | converts 1 ether to wei
@@ -151,6 +151,25 @@ pub enum Subcommands {
         #[clap(long, env = "ETH_RPC_URL")]
         rpc_url: String,
     },
+    #[clap(name = "receipt")]
+    #[clap(about = "Print information about the transaction receipt for <tx-hash>")]
+    Receipt {
+        hash: String,
+        field: Option<String>,
+        #[clap(
+            short,
+            long,
+            help = "the number of confirmations until the receipt is fetched",
+            default_value = "1"
+        )]
+        confirmations: usize,
+        #[clap(long, env = "CAST_ASYNC")]
+        cast_async: bool,
+        #[clap(long = "json", short = 'j')]
+        to_json: bool,
+        #[clap(long, env = "ETH_RPC_URL")]
+        rpc_url: String,
+    },
     #[clap(name = "send")]
     #[clap(about = "Publish a transaction signed by <from> to call <to> with <data>")]
     SendTx {