Add test for serializer

test/exq_scheduler/serializer_test.exs

@@ -0,0 +1,20 @@
+defmodule ExqScheduler.SerializerTest do
+  use ExUnit.Case
+  import ExqScheduler.Serializer
+
+  test "encode" do
+    assert stable_encode!(%{"a" => 1}) == ~S({"a":1})
+    assert stable_encode!(%{"b" => 1, "a" => 1}) == ~S({"a":1,"b":1})
+
+    size = 100
+
+    map =
+      for n <- 1..size, do: {"element_#{String.pad_leading(to_string(n), 3, "0")}", n}, into: %{}
+
+    json =
+      for n <- 1..size,
+          do: ~s("element_#{String.pad_leading(to_string(n), 3, "0")}":#{n})
+
+    assert stable_encode!(map) == "{" <> Enum.join(json, ",") <> "}"
+  end
+end