From 325029b3d4b0ed3eaf6a264ad40cc16254ee70d0 Mon Sep 17 00:00:00 2001
From: Brian Bergeron <brian.e.bergeron@gmail.com>
Date: Thu, 19 Dec 2024 09:17:34 -0800
Subject: [PATCH] handle multicall revert

---
 .../assets-controllers/src/multicall.test.ts  | 46 +++++++++++++++++++
 packages/assets-controllers/src/multicall.ts  | 26 +++++++++--
 2 files changed, 69 insertions(+), 3 deletions(-)

diff --git a/packages/assets-controllers/src/multicall.test.ts b/packages/assets-controllers/src/multicall.test.ts
index e8692ac5c3..8fbbea8911 100644
--- a/packages/assets-controllers/src/multicall.test.ts
+++ b/packages/assets-controllers/src/multicall.test.ts
@@ -122,4 +122,50 @@ describe('multicall', () => {
       ]);
     });
   });
+
+  describe('error handling of reverts', () => {
+    const call = {
+      contract: new Contract(
+        '0x0000000000000000000000000000000000000001',
+        abiERC20,
+        provider,
+      ),
+      functionSignature: 'balanceOf(address)',
+      arguments: ['0x0000000000000000000000000000000000000000'],
+    };
+
+    it('should fall back to parallel calls when multicall reverts', async () => {
+      jest.spyOn(provider, 'call').mockImplementationOnce(() => {
+        const error = { code: 'CALL_EXCEPTION' };
+        return Promise.reject(error);
+      });
+
+      jest
+        .spyOn(provider, 'call')
+        .mockImplementationOnce(() =>
+          Promise.resolve(defaultAbiCoder.encode(['uint256'], [1])),
+        );
+
+      const results = await multicallOrFallback([call], '0x1', provider);
+
+      expect(results).toMatchObject([
+        {
+          success: true,
+          // eslint-disable-next-line @typescript-eslint/naming-convention
+          value: { _hex: '0x01' },
+        },
+      ]);
+    });
+
+    it('should throw rpc errors other than revert', async () => {
+      const error = { code: 'network error' };
+      jest.spyOn(provider, 'call').mockImplementationOnce(() => {
+        return Promise.reject(error);
+      });
+
+      await expect(
+        multicallOrFallback([call], '0x1', provider),
+      ).rejects.toMatchObject(error);
+    });
+  });
 });
diff --git a/packages/assets-controllers/src/multicall.ts b/packages/assets-controllers/src/multicall.ts
index e5be69f09d..7f47952e42 100644
--- a/packages/assets-controllers/src/multicall.ts
+++ b/packages/assets-controllers/src/multicall.ts
@@ -392,7 +392,27 @@ export const multicallOrFallback = async (
   }
 
   const multicallAddress = MULTICALL_CONTRACT_BY_CHAINID[chainId];
-  return await (multicallAddress
-    ? multicall(calls, multicallAddress, provider, maxCallsPerMulticall)
-    : fallback(calls, maxCallsParallel));
+  if (multicallAddress) {
+    try {
+      return await multicall(
+        calls,
+        multicallAddress,
+        provider,
+        maxCallsPerMulticall,
+      );
+    } catch (error: unknown) {
+      // Fallback only on revert
+      // https://docs.ethers.org/v5/troubleshooting/errors/#help-CALL_EXCEPTION
+      if (
+        !error ||
+        typeof error !== 'object' ||
+        !('code' in error) ||
+        error.code !== 'CALL_EXCEPTION'
+      ) {
+        throw error;
+      }
+    }
+  }
+
+  return await fallback(calls, maxCallsParallel);
 };