From 20045ad6391470532a9e233ff48f5c291cb6dc78 Mon Sep 17 00:00:00 2001
From: Dan Cline <6798349+Rjected@users.noreply.github.com>
Date: Wed, 4 Jan 2023 15:54:14 -0500
Subject: [PATCH] feat(core): add ability to take geth stderr

 * makes the geth logs accessible by using take() on the GethInstance
   stderr
---
 ethers-core/src/utils/geth.rs | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/ethers-core/src/utils/geth.rs b/ethers-core/src/utils/geth.rs
index 8c13d1755..ce91d4920 100644
--- a/ethers-core/src/utils/geth.rs
+++ b/ethers-core/src/utils/geth.rs
@@ -5,7 +5,7 @@ use std::{
     fs::{create_dir, File},
     io::{BufRead, BufReader},
     path::PathBuf,
-    process::{Child, Command, Stdio},
+    process::{Child, ChildStderr, Command, Stdio},
     time::{Duration, Instant},
 };
 
@@ -76,7 +76,17 @@ impl GethInstance {
         &self.data_dir
     }
 
+    /// Takes the stderr contained in the child process.
+    ///
+    /// This leaves a `None` in its place, so calling methods that require a stderr to be present
+    /// will fail if called after this.
+    pub fn stderr(&mut self) -> Result<ChildStderr, GethInstanceError> {
+        self.pid.stderr.take().ok_or(GethInstanceError::NoStderr)
+    }
+
     /// Blocks until geth adds the specified peer, using 20s as the timeout.
+    ///
+    /// Requires the stderr to be present in the `GethInstance`.
     pub fn wait_to_add_peer(&mut self, id: H256) -> Result<(), GethInstanceError> {
         let mut stderr = self.pid.stderr.as_mut().ok_or(GethInstanceError::NoStderr)?;
         let mut err_reader = BufReader::new(&mut stderr);