Fixed #96

.travis.yml

@@ -2,8 +2,8 @@ dist: bionic
 sudo: required
 language: elixir
 
-elixir: 1.12.1
-otp_release: 24.0
+elixir: 1.10.2
+otp_release: 22.0
 
 addons:
   apt:

lib/mongo/ordered_bulk.ex

@@ -76,6 +76,16 @@ defmodule Mongo.OrderedBulk do
     %OrderedBulk{coll: coll}
   end
 
+  @doc """
+  Returns true, if the bulk is empty, that means it contains no inserts, updates or deletes operations
+  """
+  def empty?(%OrderedBulk{ops: []}) do
+    true
+  end
+  def empty?(_other) do
+    false
+  end
+
   @doc """
   Appends a bulk operation to the ordered bulk.
   """
@@ -207,8 +217,14 @@ defmodule Mongo.OrderedBulk do
         op, {bulk, l} -> {:cont, {push(op, bulk), l - 1}}
       end,
       fn
-        {bulk, 0} -> {:cont, bulk}
-        {bulk, _} -> {:cont, BulkWrite.write(top, bulk, opts), {new(coll), limit - 1}}
+        {bulk, _} ->
+          case empty?(bulk) do
+            true ->
+              {:cont, bulk}
+
+            false ->
+              {:cont, BulkWrite.write(top, bulk, opts), {new(coll), limit - 1}}
+          end
       end)
   end
   def write(_enum, _top, _coll, limit, _opts) when limit < 1 do

lib/mongo/unordered_bulk.ex

@@ -77,6 +77,16 @@ defmodule Mongo.UnorderedBulk do
     %UnorderedBulk{coll: coll}
   end
 
+  @doc """
+  Returns true, if the bulk is empty, that means it contains no inserts, updates or deletes operations
+  """
+  def empty?(%UnorderedBulk{inserts: [], updates: [], deletes: []}) do
+    true
+  end
+  def empty?(_other) do
+    false
+  end
+
   @doc """
   Adds the two unordered bulks together.
   """
@@ -243,8 +253,14 @@ defmodule Mongo.UnorderedBulk do
         op, {bulk, l} -> {:cont, {push(op, bulk), l - 1}}
       end,
       fn
-        {bulk, 0} -> {:cont, bulk}
-        {bulk, _} -> {:cont, BulkWrite.write(top, bulk, opts), {new(coll), limit - 1}}
+        {bulk, _} ->
+          case empty?(bulk) do
+            true ->
+              {:cont, bulk}
+
+            false ->
+              {:cont, BulkWrite.write(top, bulk, opts), {new(coll), limit - 1}}
+          end
     end)
   end
   def write(_enum, _top, _coll, limit, _opts) when limit < 1 do

test/mongo/bulk_writes_test.exs

@@ -30,6 +30,31 @@ defmodule Mongo.BulkWritesTest do
 
   end
 
+  test "check unordered bulk with limit", top do
+    coll = unique_collection()
+
+    [batch_1, batch_2] = 1..49
+                         |> Stream.map(fn i -> Mongo.BulkOps.get_insert_one(%{number: i}) end)
+                         |> Mongo.UnorderedBulk.write(top.pid, coll, 25)
+                         |> Enum.map(& &1)
+
+    assert %{:inserted_count => 25} ==  Map.take(batch_1, [:inserted_count])
+    assert %{:inserted_count => 24} ==  Map.take(batch_2, [:inserted_count])
+  end
+
+  test "check ordered bulk with limit", top do
+    coll = unique_collection()
+
+    [batch_1, batch_2] = 1..49
+                         |> Stream.map(fn i -> Mongo.BulkOps.get_insert_one(%{number: i}) end)
+                         |> Mongo.OrderedBulk.write(top.pid, coll, 25)
+                         |> Enum.map(& &1)
+
+    assert %{:inserted_count => 25} ==  Map.take(batch_1, [:inserted_count])
+    assert %{:inserted_count => 24} ==  Map.take(batch_2, [:inserted_count])
+  end
+
+
   test "check ordered bulk", top do
     coll = unique_collection()