Feature/add sorter param

README.md

@@ -14,13 +14,13 @@ It works similar like [OJSON](https://hex.pm/packages/ojson) but can output a pr
 StableJason.encode(%{c: 3, b: 2, a: 1})
 {:ok, ~S|{"a":1,"b":2,"c":3}|}
 
-StableJason.encode(%{c: 3, b: 2, a: 1}, pretty: true)
+StableJason.encode(%{c: 3, b: 2, a: 1}, :asc, pretty: true)
 {:ok, "{\n  \"a\": 1,\n  \"b\": 2,\n  \"c\": 3\n}"}
 
 StableJason.encode!(%{c: 3, b: 2, a: 1})
 "{\"a\":1,\"b\":2,\"c\":3}"
 
-StableJason.encode!(%{c: 3, b: 2, a: 1}, pretty: true)
+StableJason.encode!(%{c: 3, b: 2, a: 1}, :asc, pretty: true)
 "{\n  \"a\": 1,\n  \"b\": 2,\n  \"c\": 3\n}"
 ```
 

lib/stable_jason.ex

@@ -15,6 +15,9 @@ defmodule StableJason do
       iex> StableJason.encode(%{c: 3, b: 2, a: 1})
       {:ok, ~S|{"a":1,"b":2,"c":3}|}
 
+      iex> StableJason.encode(%{c: 3, b: 2, a: 1}, sorter: :desc)
+      {:ok, ~S|{"c":3,"b":2,"a":1}|}
+
       iex> StableJason.encode(<<0::1>>)
       {:error,
         %Protocol.UndefinedError{
@@ -24,7 +27,8 @@ defmodule StableJason do
         }}
   """
   def encode(input, opts \\ []) do
-    case Encoder.encode(input) do
+    {sorter, opts} = Keyword.pop(opts, :sorter)
+    case Encoder.encode(input, sorter || :asc) do
       {:ok, result} -> Jason.encode(result, opts)
       {:error, error} -> {:error, error}
     end
@@ -41,12 +45,16 @@ defmodule StableJason do
       iex> StableJason.encode!(%{a: 1})
       ~S|{"a":1}|
 
+      iex> StableJason.encode!(%{a: 1, b: 3}, sorter: :desc)
+      ~S|{"b":3,"a":1}|
+
       iex> StableJason.encode!("\\xFF")
       ** (Jason.EncodeError) invalid byte 0xFF in <<255>>
 
   """
   def encode!(input, opts \\ []) do
-    case Encoder.encode(input) do
+    {sorter, opts} = Keyword.pop(opts, :sorter)
+    case Encoder.encode(input, sorter || :asc) do
       {:ok, result} -> Jason.encode!(result, opts)
       {:error, error} -> raise error
     end

lib/stable_jason/encoder.ex

@@ -19,32 +19,32 @@ defmodule StableJason.Encoder do
           description: "cannot encode a bitstring to JSON"
         }}
   """
-  def encode(input) do
+  def encode(input, sorter \\ :asc) do
     case Jason.encode(input) do
-      {:ok, result} -> {:ok, encode_stable(result)}
+      {:ok, result} -> {:ok, encode_stable(result, sorter)}
       {:error, error} -> {:error, error}
     end
   end
 
-  defp encode_stable(input) when is_binary(input) do
+  defp encode_stable(input, sorter) when is_binary(input) do
     input
     |> Jason.decode!(%{objects: :ordered_objects})
-    |> do_encode_stable()
+    |> do_encode_stable(sorter)
   end
 
-  defp do_encode_stable(%Jason.OrderedObject{} = ordered_object) do
+  defp do_encode_stable(%Jason.OrderedObject{} = ordered_object, sorter) do
     stable_values =
-      for {k, v} <- List.keysort(ordered_object.values, 0) do
-        {k, do_encode_stable(v)}
+      for {k, v} <- List.keysort(ordered_object.values, 0, sorter) do
+        {k, do_encode_stable(v, sorter)}
       end
 
     %Jason.OrderedObject{values: stable_values}
   end
 
-  defp do_encode_stable(input) when is_list(input) do
+  defp do_encode_stable(input, sorter) when is_list(input) do
     input
-    |> Enum.map(&do_encode_stable/1)
+    |> Enum.map(fn i -> do_encode_stable(i, sorter) end)
   end
 
-  defp do_encode_stable(input), do: input
+  defp do_encode_stable(input, _sorter), do: input
 end

mix.exs

@@ -1,14 +1,14 @@
 defmodule StableJason.MixProject do
   use Mix.Project
 
-  @version "1.0.0"
+  @version "2.0.0"
   @source_url "https://github.com/egze/stable_jason"
 
   def project do
     [
       app: :stable_jason,
       version: @version,
-      elixir: "~> 1.13",
+      elixir: "~> 1.14",
       start_permanent: Mix.env() == :prod,
       deps: deps(),
       description: description(),

test/stable_jason/encoder_test.exs

@@ -28,7 +28,7 @@ defmodule StableJason.EncoderTest do
     end
 
     test "nested map with more complex data types" do
-      input = %{c: 3, b: %{d: Date.utc_today(), a: 1.5}, a: 1}
+      input = %{c: 3, b: %{d: ~D[2024-01-18], a: 1.5}, a: 1}
 
       assert Encoder.encode(input) ==
                {:ok,
@@ -60,5 +60,25 @@ defmodule StableJason.EncoderTest do
                   1
                 ]}
     end
+
+    test "using a sorter atom" do
+      input = %{a: 5, aa: 4, b: 9, A: 12}
+
+      assert Encoder.encode(input, :desc) ==
+               {:ok, %Jason.OrderedObject{values: [{"b", 9}, {"aa", 4}, {"a", 5}, {"A", 12}]}}
+    end
+
+    test "using a sorter function" do
+      input = %{a: 5, aa: 4, b: 9, A: 12}
+
+      sorter = fn a, b ->
+        if String.length(inspect(a)) == String.length(inspect(b)),
+          do: a < b,
+          else: String.length(inspect(a)) < String.length(inspect(b))
+      end
+
+      assert Encoder.encode(input, sorter) ==
+               {:ok, %Jason.OrderedObject{values: [{"A", 12}, {"a", 5}, {"b", 9}, {"aa", 4}]}}
+    end
   end
 end