From 56f2482508f2ba71bd6b0295c70c6abca7101e57 Mon Sep 17 00:00:00 2001
From: Dmitry Blues <dmitri.blyus@gmail.com>
Date: Fri, 27 Sep 2024 20:00:19 +0200
Subject: [PATCH] Fix race condition in injected.ts (#4207)

* Fix race condition in injected.ts

It can hangs if "once" catches an event with unexpected chainId

* chore: tweaks

---------

Co-authored-by: Tom Meagher <tom@meagher.co>
---
 .changeset/hungry-colts-flow.md          |  6 ++++++
 packages/connectors/src/metaMask.ts      | 14 +++++++++-----
 packages/core/src/connectors/injected.ts | 14 +++++++++-----
 3 files changed, 24 insertions(+), 10 deletions(-)
 create mode 100644 .changeset/hungry-colts-flow.md

diff --git a/.changeset/hungry-colts-flow.md b/.changeset/hungry-colts-flow.md
new file mode 100644
index 0000000000..fd49674a1c
--- /dev/null
+++ b/.changeset/hungry-colts-flow.md
@@ -0,0 +1,6 @@
+---
+"@wagmi/connectors": patch
+"@wagmi/core": patch
+---
+
+Updated chain switch listener for `injected` and `metaMask` to be more robust.
diff --git a/packages/connectors/src/metaMask.ts b/packages/connectors/src/metaMask.ts
index 2331621f9b..e3b4f908cd 100644
--- a/packages/connectors/src/metaMask.ts
+++ b/packages/connectors/src/metaMask.ts
@@ -239,11 +239,15 @@ export function metaMask(parameters: MetaMaskParameters = {}) {
               if (currentChainId === chainId)
                 config.emitter.emit('change', { chainId })
             }),
-          new Promise<void>((resolve) =>
-            config.emitter.once('change', ({ chainId: currentChainId }) => {
-              if (currentChainId === chainId) resolve()
-            }),
-          ),
+          new Promise<void>((resolve) => {
+            const listener = ((data) => {
+              if ('chainId' in data && data.chainId === chainId) {
+                config.emitter.off('change', listener)
+                resolve()
+              }
+            }) satisfies Parameters<typeof config.emitter.on>[1]
+            config.emitter.on('change', listener)
+          }),
         ])
         return chain
       } catch (err) {
diff --git a/packages/core/src/connectors/injected.ts b/packages/core/src/connectors/injected.ts
index 84fdc06e8e..c242094d58 100644
--- a/packages/core/src/connectors/injected.ts
+++ b/packages/core/src/connectors/injected.ts
@@ -428,11 +428,15 @@ export function injected(parameters: InjectedParameters = {}) {
               if (currentChainId === chainId)
                 config.emitter.emit('change', { chainId })
             }),
-          new Promise<void>((resolve) =>
-            config.emitter.once('change', ({ chainId: currentChainId }) => {
-              if (currentChainId === chainId) resolve()
-            }),
-          ),
+          new Promise<void>((resolve) => {
+            const listener = ((data) => {
+              if ('chainId' in data && data.chainId === chainId) {
+                config.emitter.off('change', listener)
+                resolve()
+              }
+            }) satisfies Parameters<typeof config.emitter.on>[1]
+            config.emitter.on('change', listener)
+          }),
         ])
         return chain
       } catch (err) {