From 9cb8ee7e92d7563fe274fdc17536bdbd689ad4fa Mon Sep 17 00:00:00 2001
From: Luke Imhoff <luke.imhoff@dockyard.com>
Date: Tue, 8 May 2018 22:20:05 -0500
Subject: [PATCH] Happy-path tests for Explorer.Indexer.AddressFetcher

---
 .../lib/explorer/indexer/address_fetcher.ex   |  5 +-
 .../explorer/indexer/address_fetcher_test.exs | 85 +++++++++++++++++++
 coveralls.json                                |  2 +-
 3 files changed, 89 insertions(+), 3 deletions(-)
 create mode 100644 apps/explorer/test/explorer/indexer/address_fetcher_test.exs

diff --git a/apps/explorer/lib/explorer/indexer/address_fetcher.ex b/apps/explorer/lib/explorer/indexer/address_fetcher.ex
index b972f6c365..91f69cd9b6 100644
--- a/apps/explorer/lib/explorer/indexer/address_fetcher.ex
+++ b/apps/explorer/lib/explorer/indexer/address_fetcher.ex
@@ -31,7 +31,8 @@ defmodule Explorer.Indexer.AddressFetcher do
     state = %{
       debug_logs: Keyword.get(opts, :debug_logs, false),
       flush_timer: nil,
-      fetch_interval: @fetch_interval,
+      fetch_interval: Keyword.get(opts, :fetch_interval, @fetch_interval),
+      max_batch_size: Keyword.get(opts, :max_batch_size, @max_batch_size),
       buffer: :queue.new(),
       tasks: %{}
     }
@@ -90,7 +91,7 @@ defmodule Explorer.Indexer.AddressFetcher do
     |> Chain.stream_unfetched_addresses(fn %Address{hash: hash}, batch ->
       batch = :queue.in(Hash.to_string(hash), batch)
 
-      if :queue.len(batch) >= @max_batch_size do
+      if :queue.len(batch) >= state.max_batch_size do
         schedule_async_fetch(:queue.to_list(batch))
         :queue.new()
       else
diff --git a/apps/explorer/test/explorer/indexer/address_fetcher_test.exs b/apps/explorer/test/explorer/indexer/address_fetcher_test.exs
new file mode 100644
index 0000000000..7fafffc6fa
--- /dev/null
+++ b/apps/explorer/test/explorer/indexer/address_fetcher_test.exs
@@ -0,0 +1,85 @@
+defmodule Explorer.Indexer.AddressFetcherTest do
+  # MUST be `async: false` so that {:shared, pid} is set for connection to allow AddressFetcher's self-send to have
+  # connection allowed immediately.
+  use Explorer.DataCase, async: false
+
+  alias Explorer.Chain.Address
+  alias Explorer.JSONRPC
+  alias Explorer.Indexer.AddressFetcher
+
+  @hash %Explorer.Chain.Hash{
+    byte_count: 20,
+    bytes: <<139, 243, 141, 71, 100, 146, 144, 100, 242, 212, 211, 165, 101, 32, 167, 106, 179, 223, 65, 91>>
+  }
+
+  setup do
+    start_supervised!({JSONRPC, []})
+    start_supervised!({Task.Supervisor, name: Explorer.Indexer.TaskSupervisor})
+
+    :ok
+  end
+
+  describe "init/1" do
+    test "fetches unfetched addresses" do
+      unfetched_address = insert(:address, hash: @hash)
+
+      assert unfetched_address.fetched_balance == nil
+      assert unfetched_address.balance_fetched_at == nil
+
+      start_address_fetcher()
+
+      fetched_address =
+        wait(fn ->
+          Repo.one!(from(address in Address, where: address.hash == ^@hash and not is_nil(address.fetched_balance)))
+        end)
+
+      refute fetched_address.balance_fetched_at == nil
+    end
+
+    test "fetches unfetched addresses when less than max batch size" do
+      insert(:address, hash: @hash)
+
+      start_address_fetcher(max_batch_size: 2)
+
+      fetched_address =
+        wait(fn ->
+          Repo.one!(from(address in Address, where: address.hash == ^@hash and not is_nil(address.fetched_balance)))
+        end)
+
+      refute fetched_address.balance_fetched_at == nil
+    end
+  end
+
+  describe "async_fetch_balances/1" do
+    test "fetches balances for address_hashes" do
+      start_address_fetcher()
+
+      assert :ok = AddressFetcher.async_fetch_balances([@hash])
+
+      address =
+        wait(fn ->
+          Repo.get!(Address, @hash)
+        end)
+
+      refute address.fetched_balance == nil
+    end
+  end
+
+  defp start_address_fetcher(options \\ []) when is_list(options) do
+    start_supervised!(
+      {AddressFetcher,
+       Keyword.merge(
+         [debug_logs: false, fetch_interval: 1, max_batch_size: 1, max_concurrency: 1],
+         options
+       )}
+    )
+  end
+
+  defp wait(producer) do
+    producer.()
+  rescue
+    Ecto.NoResultsError ->
+      Process.sleep(100)
+      wait(producer)
+  end
+end
diff --git a/coveralls.json b/coveralls.json
index 252126b717..9e27d7c3ad 100644
--- a/coveralls.json
+++ b/coveralls.json
@@ -1,7 +1,7 @@
 {
   "coverage_options": {
     "treat_no_relevant_lines_as_covered": true,
-    "minimum_coverage": 85
+    "minimum_coverage": 87.2
   },
   "terminal_options": {
     "file_column_width": 120