Prefers the built-in JSON library from Elixir 1.18.x when it's available

lib/mix/tasks/openapi.spec.json.ex

@@ -36,21 +36,33 @@
     {opts, _, _} = OptionParser.parse(argv, strict: [start_app: :boolean])
 
     Keyword.get(opts, :start_app, true) |> maybe_start_app()
-    OpenApiSpex.ExportSpec.call(argv, &encode/2, @default_filename)
+    OpenApiSpex.ExportSpec.call(argv, &export!/2, @default_filename)
   end
 
   defp maybe_start_app(true), do: Mix.Task.run("app.start")
   defp maybe_start_app(_), do: Mix.Task.run("app.config", preload_modules: true)
 
-  defp encode(spec, %{pretty: pretty}) do
-    spec
-    |> OpenApiSpex.OpenApi.json_encoder().encode(pretty: pretty)
-    |> case do
+  defp export!(spec, %{pretty: pretty}) do
+    encoder = json_encoder()
+
+    case encode(encoder, spec, pretty) do
       {:ok, json} ->
         "#{json}\n"
 
       {:error, error} ->
         Mix.raise("could not encode #{inspect(spec)}, error: #{inspect(error)}.")
     end
   end
+
+  defp json_encoder(), do: Enum.find([Jason, Poison, JSON], &Code.ensure_loaded?/1)
+
+  # Unfortunately, the built-in JSON module in Elixir 1.18.x doesn't support the `pretty` option
+  # So we need to take Jason or Poison to be able to support this feature
+
+  defp encode(JSON, _spec, true),
+    do: {:error, "the default JSON encoder does not support the pretty option"}
+
+  defp encode(JSON, spec, _pretty), do: {:ok, JSON.encode!(spec)}
+
+  defp encode(encoder, spec, pretty), do: encoder.encode(spec, pretty: pretty)
 end

lib/open_api_spex.ex

@@ -181,7 +181,7 @@ defmodule OpenApiSpex do
    - ensures the schema is linked to the module by "x-struct" extension property
    - defines a struct with keys matching the schema properties
    - defines a @type `t` for the struct
-   - derives a `Jason.Encoder` and/or `Poison.Encoder` for the struct
+   - derives a `JSON.Encoder`, `Jason.Encoder` and/or `Poison.Encoder` for the struct
 
   See `OpenApiSpex.Schema` for additional examples and details.
 
@@ -238,8 +238,8 @@ defmodule OpenApiSpex do
   - `:struct?` (boolean) - When false, prevents the automatic generation
     of a struct definition for the schema module.
   - `:derive?` (boolean) When false, prevents the automatic generation
-    of a `@derive` call for either `Poison.Encoder`
-    or `Jason.Encoder`. Using this option can
+    of a `@derive` call for either `JSON.Encoder`
+    `Poison.Encoder` or `Jason.Encoder`. Using this option can
     prevent "... protocol has already been consolidated ..."
     compiler warnings.
   """
@@ -262,7 +262,7 @@ defmodule OpenApiSpex do
 
       if Map.get(@schema, :"x-struct") == __MODULE__ do
         if Keyword.get(unquote(opts), :derive?, true) do
-          @derive Enum.filter([Poison.Encoder, Jason.Encoder], &Code.ensure_loaded?/1)
+          @derive Enum.filter([JSON.Encoder, Poison.Encoder, Jason.Encoder], &Code.ensure_loaded?/1)
         end
 
         if Keyword.get(unquote(opts), :struct?, true) do

lib/open_api_spex/controller_specs.ex

@@ -386,7 +386,9 @@ defmodule OpenApiSpex.ControllerSpecs do
 
     extensions =
       spec
-      |> Enum.filter(fn {key, _val} -> is_atom(key) && String.starts_with?(to_string(key), "x-") end)
+      |> Enum.filter(fn {key, _val} ->
+        is_atom(key) && String.starts_with?(to_string(key), "x-")
+      end)
       |> Map.new(fn {key, value} -> {to_string(key), value} end)
 
     %Operation{

lib/open_api_spex/open_api.ex

@@ -70,7 +70,7 @@ defmodule OpenApiSpex.OpenApi do
   """
   @callback spec() :: t
 
-  @json_encoder Enum.find([Jason, Poison], &Code.ensure_loaded?/1)
+  @json_encoder Enum.find([JSON, Jason, Poison], &Code.ensure_loaded?/1)
   @yaml_encoder nil
   @vendor_extensions ~w(
     x-struct
@@ -80,7 +80,7 @@ defmodule OpenApiSpex.OpenApi do
 
   def json_encoder, do: @json_encoder
 
-  for encoder <- [Poison.Encoder, Jason.Encoder] do
+  for encoder <- [JSON.Encoder, Poison.Encoder, Jason.Encoder] do
     if Code.ensure_loaded?(encoder) do
       defimpl encoder do
         def encode(api_spec = %OpenApi{}, options) do

lib/open_api_spex/plug/render_spec.ex

@@ -25,7 +25,7 @@ defmodule OpenApiSpex.Plug.RenderSpec do
 
   @behaviour Plug
 
-  @json_encoder Enum.find([Jason, Poison], &Code.ensure_loaded?/1)
+  @json_encoder Enum.find([JSON, Jason, Poison], &Code.ensure_loaded?/1)
 
   @impl Plug
   def init(opts), do: opts