fix(bridge-ui): set to null when chainID is not one of the two supported, so prevchain can be checked

packages/bridge-ui/src/utils/switchNetwork.ts

@@ -1,5 +1,43 @@
+import { get } from 'svelte/store';
 import { switchNetwork as wagmiSwitchNetwork } from 'wagmi/actions';
 
+import { srcChain } from '../store/chain';
+import { Deferred } from './Deferred';
+
 export async function switchNetwork(chainId: number) {
+  const prevChainId = get(srcChain)?.id;
+
+  if (prevChainId === chainId) return;
+
   await wagmiSwitchNetwork({ chainId });
+
+  // What are we doing here? we have a watcher waiting for network changes.
+  // When this happens this watcher is called and takes care of setting
+  // the signer and chains in the store. We are actually waiting here
+  // for these stores to change due to some race conditions in the UI.
+  // There will be a better design around this in alpha-4: fewer stores
+  // and '$:' tags. They're evil.
+  const deferred = new Deferred<void>();
+
+  // This will prevent an unlikely infinite loop
+  const starting = Date.now();
+  const timeout = 5000; // TODO: config?
+
+  const waitForNetworkChange = () => {
+    const srcChainId = get(srcChain)?.id;
+
+    if (srcChainId && srcChainId !== prevChainId) {
+      // We have finally set the chain in the store. We're done here.
+      deferred.resolve();
+    } else if (Date.now() > starting + timeout) {
+      // Wait, what???
+      deferred.reject(new Error('timeout switching network'));
+    } else {
+      setTimeout(waitForNetworkChange, 300); // TODO: config those 300?
+    }
+  };
+
+  waitForNetworkChange();
+
+  return deferred.promise;
 }

packages/bridge-ui/src/wagmi/watcher.ts

@@ -24,6 +24,8 @@ const setChain = (chainId: number) => {
 
     log(`Network switched to ${L2Chain.name}`);
   } else {
+    srcChain.set(null);
+    destChain.set(null);
     isSwitchChainModalOpen.set(true);
   }
 };