Fix: duplicated chain ids (#554)

Fixes #551

change/@starknet-react-core-7ad8aa4e-d8ed-46e8-9231-bd5a5313e78a.json

@@ -0,0 +1,7 @@
+{
+  "type": "patch",
+  "comment": "core: fail if there is duplicated chain ids",
+  "packageName": "@starknet-react/core",
+  "email": "[email protected]",
+  "dependentChangeType": "patch"
+}

packages/core/src/context/starknet.test.tsx

@@ -4,7 +4,8 @@ import { accounts, defaultConnector } from "../../test/devnet";
 import { act, renderHook } from "../../test/react";
 import type { MockConnector } from "../connectors";
 
-import { useStarknet } from "./starknet";
+import { jsonRpcProvider } from "../providers";
+import { StarknetProvider, useStarknet } from "./starknet";
 
 describe("StarknetProvider", () => {
   it("defaults to the first chain", async () => {
@@ -82,4 +83,18 @@ describe("StarknetProvider", () => {
     expect(await result.current.connector?.chainId()).toEqual(mainnet.id);
     expect(result.current.chain.id).toEqual(mainnet.id);
   });
+
+  it("fails if there is duplicated chain ids", async () => {
+    const chains = [devnet, devnet];
+    function rpc() {
+      return {
+        nodeUrl: devnet.rpcUrls.public.http[0],
+      };
+    }
+    const provider = jsonRpcProvider({ rpc });
+
+    expect(() => StarknetProvider({ provider, chains })).toThrowError(
+      "Duplicated chain id found",
+    );
+  });
 });

packages/core/src/context/starknet.tsx

@@ -122,6 +122,16 @@ function useStarknetManager({
     throw new Error("Must provide at least one chain.");
   }
 
+  // check for duplicated ids in the chains list
+  const seen = new Set<bigint>();
+
+  for (const chain of chains) {
+    if (seen.has(chain.id)) {
+      throw new Error(`Duplicated chain id found: ${chain.id}`);
+    }
+    seen.add(chain.id);
+  }
+
   const { chain: _, provider: defaultProvider } = providerForChain(
     defaultChain,
     provider,