From 550431d41b6d786a33110b49f780f7e1a67fc26f Mon Sep 17 00:00:00 2001
From: Maxime OUAIRY <maxime.ouairy-ext@consensys.net>
Date: Fri, 5 Jun 2026 07:22:10 +0200
Subject: [PATCH] feat: deduplicate USDC token on ARC mainnet

---
 .../src/AssetsController.test.ts              |  6 ++----
 packages/assets-controller/src/defaults.ts    | 19 +++++++++++++++++++
 packages/controller-utils/src/constants.ts    |  1 +
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/packages/assets-controller/src/AssetsController.test.ts b/packages/assets-controller/src/AssetsController.test.ts
index dc87406633..9865f69dbc 100644
--- a/packages/assets-controller/src/AssetsController.test.ts
+++ b/packages/assets-controller/src/AssetsController.test.ts
@@ -28,7 +28,7 @@ import type {
   DataResponse,
   FungibleAssetMetadata,
 } from './types';
-import { formatExchangeRatesForBridge } from './utils';
+import { formatExchangeRatesForBridge, normalizeAssetId } from './utils';
 
 jest.mock('./utils', () => {
   const actual = jest.requireActual<typeof import('./utils')>('./utils');
@@ -269,12 +269,10 @@ describe('AssetsController', () => {
       const defaultState = getDefaultAssetsControllerState();
       const assetIds = Object.keys(defaultState.assetsInfo);
       expect(assetIds.length).toBeGreaterThan(0);
-      // Every erc20 asset ID must contain at least one uppercase hex letter
-      // (EIP-55 checksum property) so that keys match normalizeAssetId output.
       const erc20Ids = assetIds.filter((id) => id.includes('/erc20:'));
       expect(erc20Ids.length).toBeGreaterThan(0);
       for (const id of erc20Ids) {
-        expect(id).toMatch(/\/erc20:0x[0-9a-fA-F]*[A-F][0-9a-fA-F]*/u);
+        expect(id).toBe(normalizeAssetId(id as Caip19AssetId));
       }
     });
   });
diff --git a/packages/assets-controller/src/defaults.ts b/packages/assets-controller/src/defaults.ts
index edb5be687b..576fe588ba 100644
--- a/packages/assets-controller/src/defaults.ts
+++ b/packages/assets-controller/src/defaults.ts
@@ -31,6 +31,23 @@ const MUSD_METADATA: FungibleAssetMetadata = {
   decimals: 6,
 };
 
+/**
+ * Harcoded metadata for USDC on Arc (5042/0x13b2).
+ * USDC exists as both native (18 decimals) and ERC20 (6 decimals).
+ * We choose to force-hide the native version to avoid double listing using
+ * `CHAIN_IDS_WITH_NO_NATIVE_TOKEN`.
+ * In the meantime, the code below force-shows USDC the ERC20 token.
+ */
+const USDC_ON_ARC_ASSET_ID =
+  'eip155:5042/erc20:0x3600000000000000000000000000000000000000';
+
+const USDC_ON_ARC_METADATA: FungibleAssetMetadata = {
+  type: 'erc20',
+  symbol: 'USDC',
+  name: 'USDC',
+  decimals: 6,
+};
+
 /**
  * Build the CAIP-19 asset ID for the mUSD ERC-20 token on a given EVM
  * chain.
@@ -59,6 +76,7 @@ export const DEFAULT_TRACKED_ASSETS_BY_CHAIN: ReadonlyMap<
   ['eip155:1' as ChainId, [musdAssetId('eip155:1' as ChainId)]],
   ['eip155:59144' as ChainId, [musdAssetId('eip155:59144' as ChainId)]],
   ['eip155:143' as ChainId, [musdAssetId('eip155:143' as ChainId)]],
+  ['eip155:5042' as ChainId, [USDC_ON_ARC_ASSET_ID]],
 ]);
 
 /**
@@ -79,6 +97,7 @@ export const DEFAULT_ASSET_METADATA: ReadonlyMap<string, AssetMetadata> =
     [musdAssetId('eip155:1' as ChainId), MUSD_METADATA],
     [musdAssetId('eip155:59144' as ChainId), MUSD_METADATA],
     [musdAssetId('eip155:143' as ChainId), MUSD_METADATA],
+    [USDC_ON_ARC_ASSET_ID, USDC_ON_ARC_METADATA],
   ]);
 
 /**
diff --git a/packages/controller-utils/src/constants.ts b/packages/controller-utils/src/constants.ts
index 99f23aa72d..b8a1d16894 100644
--- a/packages/controller-utils/src/constants.ts
+++ b/packages/controller-utils/src/constants.ts
@@ -336,4 +336,5 @@ export const DAYS = DAY;
 export const CHAIN_IDS_WITH_NO_NATIVE_TOKEN = [
   'eip155:42431', // Tempo Testnet
   'eip155:4217', // Tempo Mainnet
+  'eip155:5042', // Arc Mainnet
 ] as const;