From 2aec1f4c9fd4187e54bac63dfc443f2a93665192 Mon Sep 17 00:00:00 2001
From: pasqu4le <pasqu4le@gmail.com>
Date: Fri, 14 Jun 2019 17:57:30 +0200
Subject: [PATCH] Removes duplicate entries from Indexer.Fetcher.UncleBlock

---
 CHANGELOG.md                                  |  1 +
 .../lib/indexer/fetcher/uncle_block.ex        | 10 ++++---
 .../test/indexer/fetcher/uncle_block_test.exs | 30 +++++++++++++++++++
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f77cb5439a..39596363b2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -27,6 +27,7 @@
 - [#2119](https://github.com/poanetwork/blockscout/pull/2119) - fix map logging
 - [#2130](https://github.com/poanetwork/blockscout/pull/2130) - fix navigation
 - [#2149](https://github.com/poanetwork/blockscout/pull/2149) - remove pending transaction count
+- [#2177](https://github.com/poanetwork/blockscout/pull/2177) - remove duplicate entries from UncleBlock's Fetcher
 
 ### Chore
 - [#2127](https://github.com/poanetwork/blockscout/pull/2127) - use previouse chromedriver version
diff --git a/apps/indexer/lib/indexer/fetcher/uncle_block.ex b/apps/indexer/lib/indexer/fetcher/uncle_block.ex
index 213604a73e..e9300d1e39 100644
--- a/apps/indexer/lib/indexer/fetcher/uncle_block.ex
+++ b/apps/indexer/lib/indexer/fetcher/uncle_block.ex
@@ -71,17 +71,19 @@ defmodule Indexer.Fetcher.UncleBlock do
   @impl BufferedTask
   @decorate trace(name: "fetch", resource: "Indexer.Fetcher.UncleBlock.run/2", service: :indexer, tracer: Tracer)
   def run(entries, %Block.Fetcher{json_rpc_named_arguments: json_rpc_named_arguments} = block_fetcher) do
-    entry_count = Enum.count(entries)
+    unique_entries = Enum.uniq(entries)
+
+    entry_count = Enum.count(unique_entries)
     Logger.metadata(count: entry_count)
 
     Logger.debug("fetching")
 
-    entries
+    unique_entries
     |> Enum.map(&entry_to_params/1)
     |> EthereumJSONRPC.fetch_uncle_blocks(json_rpc_named_arguments)
     |> case do
       {:ok, blocks} ->
-        run_blocks(blocks, block_fetcher, entries)
+        run_blocks(blocks, block_fetcher, unique_entries)
 
       {:error, reason} ->
         Logger.error(
@@ -91,7 +93,7 @@ defmodule Indexer.Fetcher.UncleBlock do
           error_count: entry_count
         )
 
-        {:retry, entries}
+        {:retry, unique_entries}
     end
   end
 
diff --git a/apps/indexer/test/indexer/fetcher/uncle_block_test.exs b/apps/indexer/test/indexer/fetcher/uncle_block_test.exs
index f3350b8de7..93a11b0b64 100644
--- a/apps/indexer/test/indexer/fetcher/uncle_block_test.exs
+++ b/apps/indexer/test/indexer/fetcher/uncle_block_test.exs
@@ -169,6 +169,36 @@ defmodule Indexer.Fetcher.UncleBlockTest do
       assert {:retry, ^entries} =
                UncleBlock.run(entries, %Block.Fetcher{json_rpc_named_arguments: json_rpc_named_arguments})
     end
+
+    test "retries only unique uncles on failed request", %{json_rpc_named_arguments: json_rpc_named_arguments} do
+      %Hash{bytes: block_hash_bytes} = block_hash()
+      entry = {block_hash_bytes, 0}
+      entries = [entry, entry]
+
+      EthereumJSONRPC.Mox
+      |> expect(:json_rpc, fn [
+                                %{
+                                  id: id,
+                                  method: "eth_getUncleByBlockHashAndIndex"
+                                }
+                              ],
+                              _ ->
+        {:ok,
+         [
+           %{
+             id: id,
+             error: %{
+               code: 404,
+               data: %{index: 0, nephew_hash: "0xa0814f0478fe90c82852f812fd74c96df148654c326d2600d836e6908ebb62b4"},
+               message: "Not Found"
+             }
+           }
+         ]}
+      end)
+
+      assert {:retry, [entry]} =
+               UncleBlock.run(entries, %Block.Fetcher{json_rpc_named_arguments: json_rpc_named_arguments})
+    end
   end
 
   describe "run_blocks/2" do