Merge pull request #2616 from poanetwork/ab-remove-duplicates-from-coin-history

deduplicate coin history records by delta

CHANGELOG.md

@@ -8,6 +8,7 @@
 
 ### Fixes
 - [#2623](https://github.com/poanetwork/blockscout/pull/2623) - fix a blinking test
+- [#2616](https://github.com/poanetwork/blockscout/pull/2616) - deduplicate coin history records by delta
 - [#2613](https://github.com/poanetwork/blockscout/pull/2613) - fix getminedblocks rpc endpoint
 - [#2592](https://github.com/poanetwork/blockscout/pull/2592) - process new metadata format for whisper
 - [#2572](https://github.com/poanetwork/blockscout/pull/2572) - Ease non-critical css

apps/explorer/lib/explorer/chain.ex

@@ -2967,6 +2967,13 @@ defmodule Explorer.Chain do
     |> CoinBalance.fetch_coin_balances(paging_options)
     |> page_coin_balances(paging_options)
     |> Repo.all()
+    |> Enum.dedup_by(fn record ->
+      if record.delta == Decimal.new(0) do
+        :dup
+      else
+        System.unique_integer()
+      end
+    end)
   end
 
   def get_coin_balance(address_hash, block_number) do

apps/explorer/test/explorer/chain_test.exs

@@ -4159,4 +4159,30 @@ defmodule Explorer.ChainTest do
       assert Chain.staking_pools_count(:inactive) == 1
     end
   end
+
+  describe "address_to_coin_balances/2" do
+    test "deduplicates records by zero delta" do
+      address = insert(:address)
+
+      1..5
+      |> Enum.each(fn block_number ->
+        insert(:block, number: block_number)
+        insert(:fetched_balance, value: 1, block_number: block_number, address_hash: address.hash)
+      end)
+
+      insert(:block, number: 6)
+      insert(:fetched_balance, value: 2, block_number: 6, address_hash: address.hash)
+
+      assert [first, second, third] = Chain.address_to_coin_balances(address.hash, [])
+
+      assert first.block_number == 6
+      assert first.delta == Decimal.new(1)
+
+      assert second.block_number == 5
+      assert second.delta == Decimal.new(0)
+
+      assert third.block_number == 1
+      assert third.delta == Decimal.new(1)
+    end
+  end
 end