Merge pull request #5019 from blockscout/vb-fetch_last_token_balance-error-fix

Fix fetch_last_token_balance function termination

CHANGELOG.md

@@ -8,6 +8,7 @@
 - [#4931](https://github.com/blockscout/blockscout/pull/4931) - Web3 modal with Wallet Connect for Write contract page and Staking Dapp
 
 ### Fixes
+- [#5019](https://github.com/blockscout/blockscout/pull/5019) - Fix fetch_last_token_balance function termination
 - [#5011](https://github.com/blockscout/blockscout/pull/5011) - Fix `0x0` implementation address
 - [#5008](https://github.com/blockscout/blockscout/pull/5008) - Extend decimals cap in format_according_to_decimals up to 24
 - [#5005](https://github.com/blockscout/blockscout/pull/5005) - Fix falsy appearance `Connection Lost` warning on reload/switch page

apps/explorer/lib/explorer/chain.ex

@@ -5654,16 +5654,22 @@ defmodule Explorer.Chain do
 
   @spec fetch_last_token_balance(Hash.Address.t(), Hash.Address.t()) :: Decimal.t()
   def fetch_last_token_balance(address_hash, token_contract_address_hash) do
-    address_hash
-    |> CurrentTokenBalance.last_token_balance(token_contract_address_hash)
-    |> Repo.one() || Decimal.new(0)
+    if address_hash !== %{} do
+      address_hash
+      |> CurrentTokenBalance.last_token_balance(token_contract_address_hash) || Decimal.new(0)
+    else
+      Decimal.new(0)
+    end
   end
 
   # @spec fetch_last_token_balance_1155(Hash.Address.t(), Hash.Address.t()) :: Decimal.t()
   def fetch_last_token_balance_1155(address_hash, token_contract_address_hash, token_id) do
-    address_hash
-    |> CurrentTokenBalance.last_token_balance_1155(token_contract_address_hash, token_id)
-    |> Repo.one() || Decimal.new(0)
+    if address_hash !== %{} do
+      address_hash
+      |> CurrentTokenBalance.last_token_balance_1155(token_contract_address_hash, token_id) || Decimal.new(0)
+    else
+      Decimal.new(0)
+    end
   end
 
   @spec address_to_coin_balances(Hash.Address.t(), [paging_options]) :: []

apps/explorer/lib/explorer/chain/address/current_token_balance.ex

@@ -11,7 +11,7 @@ defmodule Explorer.Chain.Address.CurrentTokenBalance do
   import Ecto.Changeset
   import Ecto.Query, only: [from: 2, limit: 2, offset: 2, order_by: 3, preload: 2]
 
-  alias Explorer.{Chain, PagingOptions}
+  alias Explorer.{Chain, PagingOptions, Repo}
   alias Explorer.Chain.{Address, Block, BridgedToken, Hash, Token}
 
   @default_paging_options %PagingOptions{page_size: 50}
@@ -188,25 +188,33 @@ defmodule Explorer.Chain.Address.CurrentTokenBalance do
   Builds an `t:Ecto.Query.t/0` to fetch the current balance of the given address for the given token.
   """
   def last_token_balance(address_hash, token_contract_address_hash) do
-    from(
-      tb in __MODULE__,
-      where: tb.token_contract_address_hash == ^token_contract_address_hash,
-      where: tb.address_hash == ^address_hash,
-      select: tb.value
-    )
+    query =
+      from(
+        tb in __MODULE__,
+        where: tb.token_contract_address_hash == ^token_contract_address_hash,
+        where: tb.address_hash == ^address_hash,
+        select: tb.value
+      )
+
+    query
+    |> Repo.one()
   end
 
   @doc """
   Builds an `t:Ecto.Query.t/0` to fetch the current balance of the given address for the given token and token_id
   """
   def last_token_balance_1155(address_hash, token_contract_address_hash, token_id) do
-    from(
-      ctb in __MODULE__,
-      where: ctb.token_contract_address_hash == ^token_contract_address_hash,
-      where: ctb.address_hash == ^address_hash,
-      where: ctb.token_id == ^token_id,
-      select: ctb.value
-    )
+    query =
+      from(
+        ctb in __MODULE__,
+        where: ctb.token_contract_address_hash == ^token_contract_address_hash,
+        where: ctb.address_hash == ^address_hash,
+        where: ctb.token_id == ^token_id,
+        select: ctb.value
+      )
+
+    query
+    |> Repo.one()
   end
 
   @doc """