From f62fffb4ebac83cb681ce3f21463bb206bd2512f Mon Sep 17 00:00:00 2001
From: Andrea Simeoni <andreasimeoni84@gmail.com>
Date: Mon, 7 Nov 2022 21:21:24 +0100
Subject: [PATCH] Examples event streams (#1839)

* Example to subscribe events from an abigen compiled contract

* Example to subscribe events from an abigen compiled contract including `LogMeta`

* Added typo to help users run Ws examples

* cargo +nightly fmt

* Fix examples docs

Co-authored-by: Andrea Simeoni <>
---
 examples/subscribe_contract_events.rs         | 38 +++++++++++++
 .../subscribe_contract_events_with_meta.rs    | 53 +++++++++++++++++++
 examples/subscribe_logs.rs                    |  2 +
 3 files changed, 93 insertions(+)
 create mode 100644 examples/subscribe_contract_events.rs
 create mode 100644 examples/subscribe_contract_events_with_meta.rs

diff --git a/examples/subscribe_contract_events.rs b/examples/subscribe_contract_events.rs
new file mode 100644
index 00000000..a6f769f9
--- /dev/null
+++ b/examples/subscribe_contract_events.rs
@@ -0,0 +1,38 @@
+use ethers::prelude::*;
+use eyre::Result;
+use std::sync::Arc;
+
+// Generate the type-safe contract bindings by providing the ABI
+// definition in human readable format
+abigen!(
+    ERC20,
+    r#"[
+        event  Transfer(address indexed src, address indexed dst, uint wad)
+    ]"#,
+);
+
+// In order to run this example you need to include Ws and TLS features
+// Run this example with
+// `cargo run -p ethers --example subscribe_contract_events --features="ws","rustls"`
+#[tokio::main]
+async fn main() -> Result<()> {
+    let client =
+        Provider::<Ws>::connect("wss://mainnet.infura.io/ws/v3/c60b0bb42f8a4c6481ecd229eddaca27")
+            .await?;
+
+    let client = Arc::new(client);
+
+    // WETH Token
+    let address = "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2".parse::<Address>()?;
+    let weth = ERC20::new(address, Arc::clone(&client));
+
+    // Subscribe Transfer events
+    let events = weth.events();
+    let mut stream = events.stream().await?;
+
+    while let Some(Ok(event)) = stream.next().await {
+        println!("src: {:?}, dst: {:?}, wad: {:?}", event.src, event.dst, event.wad);
+    }
+
+    Ok(())
+}
diff --git a/examples/subscribe_contract_events_with_meta.rs b/examples/subscribe_contract_events_with_meta.rs
new file mode 100644
index 00000000..c81b4da8
--- /dev/null
+++ b/examples/subscribe_contract_events_with_meta.rs
@@ -0,0 +1,53 @@
+use ethers::prelude::*;
+use eyre::Result;
+use std::sync::Arc;
+
+// Generate the type-safe contract bindings by providing the ABI
+// definition in human readable format
+abigen!(
+    ERC20,
+    r#"[
+        event  Transfer(address indexed src, address indexed dst, uint wad)
+    ]"#,
+);
+
+// In order to run this example you need to include Ws and TLS features
+// Run this example with
+// `cargo run -p ethers --example subscribe_contract_events_with_meta --features="ws","rustls"`
+#[tokio::main]
+async fn main() -> Result<()> {
+    let client =
+        Provider::<Ws>::connect("wss://mainnet.infura.io/ws/v3/c60b0bb42f8a4c6481ecd229eddaca27")
+            .await?;
+
+    let client = Arc::new(client);
+
+    // WETH Token
+    let address = "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2".parse::<Address>()?;
+    let weth = ERC20::new(address, Arc::clone(&client));
+
+    // Subscribe Transfer events
+    let events = weth.events();
+    let mut stream = events.stream().await?.with_meta();
+    while let Some(Ok((event, meta))) = stream.next().await {
+        println!("src: {:?}, dst: {:?}, wad: {:?}", event.src, event.dst, event.wad);
+
+        println!(
+            r#"address: {:?}, 
+               block_number: {:?}, 
+               block_hash: {:?}, 
+               transaction_hash: {:?}, 
+               transaction_index: {:?}, 
+               log_index: {:?}
+            "#,
+            meta.address,
+            meta.block_number,
+            meta.block_hash,
+            meta.transaction_hash,
+            meta.transaction_index,
+            meta.log_index
+        );
+    }
+
+    Ok(())
+}
diff --git a/examples/subscribe_logs.rs b/examples/subscribe_logs.rs
index 18216db9..0c74f78f 100644
--- a/examples/subscribe_logs.rs
+++ b/examples/subscribe_logs.rs
@@ -2,6 +2,8 @@ use ethers::{abi::AbiDecode, prelude::*, utils::keccak256};
 use eyre::Result;
 use std::sync::Arc;
 
+// In order to run this example you need to include Ws and TLS features
+// Run this example with `cargo run -p ethers --example subscribe_logs --features="ws","rustls"`
 #[tokio::main]
 async fn main() -> Result<()> {
     let client =