From 58f8713292b7886a46f13bcf3f910d8d852d8757 Mon Sep 17 00:00:00 2001
From: Justin Starry <justin@solana.com>
Date: Wed, 29 Sep 2021 15:50:27 -0400
Subject: [PATCH] explorer: Display confirmed block's child slot (#20322)

---
 explorer/src/components/block/BlockOverviewCard.tsx | 8 ++++++++
 explorer/src/providers/block.tsx                    | 8 +++++---
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/explorer/src/components/block/BlockOverviewCard.tsx b/explorer/src/components/block/BlockOverviewCard.tsx
index 514f1d72f..162f3f58f 100644
--- a/explorer/src/components/block/BlockOverviewCard.tsx
+++ b/explorer/src/components/block/BlockOverviewCard.tsx
@@ -98,6 +98,14 @@ export function BlockOverviewCard({
               <span>{block.previousBlockhash}</span>
             </td>
           </tr>
+          {confirmedBlock.data.child && (
+            <tr>
+              <td className="w-100">Child Slot</td>
+              <td className="text-lg-right text-monospace">
+                <Slot slot={confirmedBlock.data.child} link />
+              </td>
+            </tr>
+          )}
           <tr>
             <td className="w-100">Processed Transactions</td>
             <td className="text-lg-right text-monospace">
diff --git a/explorer/src/providers/block.tsx b/explorer/src/providers/block.tsx
index facf9102f..724132bb2 100644
--- a/explorer/src/providers/block.tsx
+++ b/explorer/src/providers/block.tsx
@@ -17,6 +17,7 @@ export enum ActionType {
 
 type Block = {
   block?: BlockResponse;
+  child?: number;
 };
 
 type State = Cache.State<Block>;
@@ -71,13 +72,14 @@ export async function fetchBlock(
   let data: Block | undefined = undefined;
 
   try {
-    const connection = new Connection(url, "finalized");
-    const block = await connection.getBlock(Number(key));
+    const connection = new Connection(url, "confirmed");
+    const block = await connection.getBlock(key);
+    const child = (await connection.getBlocks(key + 1, key + 100)).shift();
     if (block === null) {
       data = {};
       status = FetchStatus.Fetched;
     } else {
-      data = { block };
+      data = { block, child };
       status = FetchStatus.Fetched;
     }
   } catch (err) {