fix(stores-eth): trigger batch rebuild on EVM RPC endpoint change

Previously the rebuild reaction tracked only the refcount set, so a
runtime endpoint change (Keplr custom RPC configuration) left
batchQueries bound to the stale URL until the contract set happened
to change again. Include the current RPC URL in the reaction key and
in waitFreshResponse's match predicate, and check refcount.size for
the empty-contracts branch instead of relying on the key string.

Author: piatoss3612

packages/stores-eth/src/queries/erc20-balance-batch.ts

@@ -36,7 +36,12 @@ export class ObservableQueryEthereumERC20BalancesBatchParent {
     makeObservable(this);
 
     reaction(
-      () => Array.from(this.refcount.keys()).sort().join(","),
+      () => {
+        const keys = Array.from(this.refcount.keys()).sort().join(",");
+        // Include the RPC URL so a runtime endpoint change (user-configured
+        // custom RPC) triggers a rebuild against the new endpoint.
+        return `${this.getRpcUrl()}::${keys}`;
+      },
       (key) => this.rebuildBatchQueries(key),
       { fireImmediately: true, delay: REBUILD_DEBOUNCE_MS }
     );
@@ -98,19 +103,21 @@ export class ObservableQueryEthereumERC20BalancesBatchParent {
     return undefined;
   }
 
+  protected currentKey(): string {
+    const keys = Array.from(this.refcount.keys()).sort().join(",");
+    return `${this.getRpcUrl()}::${keys}`;
+  }
+
   async waitFreshResponse(): Promise<void> {
     // The reaction that rebuilds batchQueries is debounced, so refcount can
     // change without batchQueries catching up. Wait until the built key
-    // matches the current refcount keys.
-    await when(
-      () =>
-        Array.from(this.refcount.keys()).sort().join(",") === this.lastBuiltKey
-    );
+    // matches the current (refcount + rpc) snapshot.
+    await when(() => this.currentKey() === this.lastBuiltKey);
     await Promise.all(this.batchQueries.map((q) => q.waitFreshResponse()));
   }
 
   protected rebuildBatchQueries(key: string): void {
-    if (key === "") {
+    if (this.refcount.size === 0) {
       runInAction(() => {
         this.batchQueries = [];
         this.lastBuiltKey = key;