Refactor cataloged token query to Chain.Token

apps/explorer/lib/explorer/chain.ex

@@ -1950,15 +1950,8 @@ defmodule Explorer.Chain do
   def stream_cataloged_token_contract_address_hashes(initial_acc, reducer) when is_function(reducer, 2) do
     Repo.transaction(
       fn ->
-        query =
-          from(
-            token in Token,
-            select: token.contract_address_hash,
-            where: token.cataloged == true,
-            order_by: [asc: token.updated_at]
-          )
-
-        query
+        Chain.Token.cataloged_tokens()
+        |> Ecto.Query.order_by([asc: :updated_at])
         |> Repo.stream(timeout: :infinity)
         |> Enum.reduce(initial_acc, reducer)
       end,

apps/explorer/lib/explorer/chain/token.ex

@@ -94,4 +94,17 @@ defmodule Explorer.Chain.Token do
       on: tt.token_contract_address_hash == t.contract_address_hash
     )
   end
+
+  @doc """
+  Builds an `Ecto.Query` to fetch the cataloged tokens.
+
+  These are tokens with cataloged field set to true.
+  """
+  def cataloged_tokens() do
+    from(
+      token in __MODULE__,
+      select: token.contract_address_hash,
+      where: token.cataloged == true
+    )
+  end
 end

apps/explorer/test/explorer/chain/token_test.exs

@@ -0,0 +1,16 @@
+defmodule Explorer.Chain.TokenTest do
+  use Explorer.DataCase
+
+  import Explorer.Factory
+
+  alias Explorer.Chain
+
+  describe "cataloged_tokens/0" do
+    test "filters uncataloged tokens out" do
+      token = insert(:token, cataloged: true)
+      insert(:token, cataloged: false)
+
+      assert Repo.all(Chain.Token.cataloged_tokens()) == [token.contract_address_hash]
+    end
+  end
+end

apps/explorer/test/explorer/chain_test.exs

@@ -2756,12 +2756,29 @@ defmodule Explorer.ChainTest do
     assert Chain.stream_uncataloged_token_contract_address_hashes([], &[&1 | &2]) == {:ok, [uncatalog_address]}
   end
 
-  test "stream_cataloged_token_contract_address_hashes/2 reduces with given reducer and accumulator" do
+  describe "stream_cataloged_token_contract_address_hashes/2" do
+    test "reduces with given reducer and accumulator" do
       %Token{contract_address_hash: catalog_address} = insert(:token, cataloged: true)
       insert(:token, cataloged: false)
       assert Chain.stream_cataloged_token_contract_address_hashes([], &[&1 | &2]) == {:ok, [catalog_address]}
     end
 
+    test "sorts the tokens by updated_at in ascending order" do
+      today = DateTime.utc_now()
+      yesterday = Timex.shift(today, days: -1)
+
+      token1 = insert(:token, %{cataloged: true, updated_at: today})
+      token2 = insert(:token, %{cataloged: true, updated_at: yesterday})
+
+      expected_response =
+        [token1, token2]
+        |> Enum.sort(&(&1.updated_at < &2.updated_at))
+        |> Enum.map(&(&1.contract_address_hash))
+
+      assert Chain.stream_cataloged_token_contract_address_hashes([], &(&2 ++ [&1])) == {:ok, expected_response}
+    end
+  end
+
   describe "transaction_has_token_transfers?/1" do
     test "returns true if transaction has token transfers" do
       transaction = insert(:transaction)