various token instance fethcer fixes

1. Handle invalid json / uri
2. Do not fetch instance metadata for empty token id

apps/explorer/lib/explorer/chain.ex

@@ -2946,7 +2946,7 @@ defmodule Explorer.Chain do
         on: token.contract_address_hash == token_transfer.token_contract_address_hash,
         left_join: instance in Instance,
         on: token_transfer.token_id == instance.token_id,
-        where: token.type == ^"ERC-721" and is_nil(instance.token_id),
+        where: token.type == ^"ERC-721" and is_nil(instance.token_id) and not is_nil(token_transfer.token_id),
         distinct: [token_transfer.token_contract_address_hash, token_transfer.token_id],
         select: %{contract_address_hash: token_transfer.token_contract_address_hash, token_id: token_transfer.token_id}
       )

apps/explorer/lib/explorer/token/instance_metadata_retriever.ex

@@ -61,6 +61,11 @@ defmodule Explorer.Token.InstanceMetadataRetriever do
       {:error, %Error{reason: reason}} ->
         {:error, reason}
     end
+  rescue
+    e ->
+      Logger.error(fn -> ["Could not send request to token uri #{inspect(token_uri)}. error #{inspect(e)}"] end)
+
+      {:error, :request_error}
   end
 
   defp fetch_json(result) do

apps/explorer/test/explorer/chain_test.exs

@@ -3645,6 +3645,28 @@ defmodule Explorer.ChainTest do
       assert result.contract_address_hash == token_transfer.token_contract_address_hash
     end
 
+    test "does not fetch token transfers without token id" do
+      token_contract_address = insert(:contract_address)
+      token = insert(:token, contract_address: token_contract_address, type: "ERC-721")
+
+      transaction =
+        :transaction
+        |> insert()
+        |> with_block(insert(:block, number: 1))
+
+      insert(
+        :token_transfer,
+        block_number: 1000,
+        to_address: build(:address),
+        transaction: transaction,
+        token_contract_address: token_contract_address,
+        token: token,
+        token_id: nil
+      )
+
+      assert {:ok, []} = Chain.stream_unfetched_token_instances([], &[&1 | &2])
+    end
+
     test "do not fetch records with token instances" do
       token_contract_address = insert(:contract_address)
       token = insert(:token, contract_address: token_contract_address, type: "ERC-721")