[Elixir] Adds workaround for httpc for post/put/patch requests (#5682)

* Ensures empty body is always present for post/put/patch

* Generate samples

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ElixirClientCodegen.java

@@ -818,6 +818,23 @@ private void buildTypespec(CodegenProperty property, StringBuilder sb) {
                 sb.append(".t");
             }
         }
+
+        private boolean getRequiresHttpcWorkaround() {
+            // Only POST/PATCH/PUT are affected from the httpc bug
+            if (!(this.httpMethod.equals("POST") || this.httpMethod.equals("PATCH") || this.httpMethod.equals("PUT"))) {
+                return false;
+            }
+
+            // If theres something required for the body, the workaround is not required
+            for (CodegenParameter requiredParam : this.requiredParams) {
+                if (requiredParam.isBodyParam || requiredParam.isFormParam) {
+                    return false;
+                }
+            }
+
+            // In case there is nothing for the body, the operation requires the workaround
+            return true;
+        }
     }
 
     class ExtendedCodegenModel extends CodegenModel {

modules/openapi-generator/src/main/resources/elixir/api.mustache

@@ -67,6 +67,9 @@ defmodule {{moduleName}}.Api.{{classname}} do
     |> add_optional_params(optional_params, opts)
 {{/-first}}
 {{/optionalParams}}
+{{#requiresHttpcWorkaround}}
+    |> ensure_body()
+{{/requiresHttpcWorkaround}}
     |> Enum.into([])
     |> (&Connection.request(connection, &1)).()
     |> evaluate_response({{#responses}}{{#-first}}[

modules/openapi-generator/src/main/resources/elixir/request_builder.ex.mustache

@@ -102,6 +102,28 @@ defmodule {{moduleName}}.RequestBuilder do
     Map.update(request, location, [{key, value}], &(&1 ++ [{key, value}]))
   end
 
+  @doc """
+  Due to a bug in httpc, POST, PATCH and PUT requests will fail, if the body is empty
+
+  This function will ensure, that the body param is always set
+
+  ## Parameters
+
+  - request (Map) - Collected request options
+
+  ## Returns
+
+  Map
+  """
+  @spec ensure_body(map()) :: map()
+  def ensure_body(%{body: nil} = request) do
+    %{request | body: ""}
+  end
+
+  def ensure_body(request) do
+    Map.put_new(request, :body, "")
+  end
+
   @doc """
   Handle the response for a Tesla request
 

samples/client/petstore/elixir/lib/openapi_petstore/api/fake.ex

@@ -60,6 +60,7 @@ defmodule OpenapiPetstore.Api.Fake do
     |> method(:post)
     |> url("/fake/outer/boolean")
     |> add_optional_params(optional_params, opts)
+    |> ensure_body()
     |> Enum.into([])
     |> (&Connection.request(connection, &1)).()
     |> evaluate_response([
@@ -89,6 +90,7 @@ defmodule OpenapiPetstore.Api.Fake do
     |> method(:post)
     |> url("/fake/outer/composite")
     |> add_optional_params(optional_params, opts)
+    |> ensure_body()
     |> Enum.into([])
     |> (&Connection.request(connection, &1)).()
     |> evaluate_response([
@@ -118,6 +120,7 @@ defmodule OpenapiPetstore.Api.Fake do
     |> method(:post)
     |> url("/fake/outer/number")
     |> add_optional_params(optional_params, opts)
+    |> ensure_body()
     |> Enum.into([])
     |> (&Connection.request(connection, &1)).()
     |> evaluate_response([
@@ -147,6 +150,7 @@ defmodule OpenapiPetstore.Api.Fake do
     |> method(:post)
     |> url("/fake/outer/string")
     |> add_optional_params(optional_params, opts)
+    |> ensure_body()
     |> Enum.into([])
     |> (&Connection.request(connection, &1)).()
     |> evaluate_response([
@@ -457,6 +461,7 @@ defmodule OpenapiPetstore.Api.Fake do
     |> add_param(:query, :"http", http)
     |> add_param(:query, :"url", url)
     |> add_param(:query, :"context", context)
+    |> ensure_body()
     |> Enum.into([])
     |> (&Connection.request(connection, &1)).()
     |> evaluate_response([

samples/client/petstore/elixir/lib/openapi_petstore/api/pet.ex

@@ -207,6 +207,7 @@ defmodule OpenapiPetstore.Api.Pet do
     |> method(:post)
     |> url("/pet/#{pet_id}")
     |> add_optional_params(optional_params, opts)
+    |> ensure_body()
     |> Enum.into([])
     |> (&Connection.request(connection, &1)).()
     |> evaluate_response([
@@ -239,6 +240,7 @@ defmodule OpenapiPetstore.Api.Pet do
     |> method(:post)
     |> url("/pet/#{pet_id}/uploadImage")
     |> add_optional_params(optional_params, opts)
+    |> ensure_body()
     |> Enum.into([])
     |> (&Connection.request(connection, &1)).()
     |> evaluate_response([

samples/client/petstore/elixir/lib/openapi_petstore/request_builder.ex

@@ -105,6 +105,28 @@ defmodule OpenapiPetstore.RequestBuilder do
     Map.update(request, location, [{key, value}], &(&1 ++ [{key, value}]))
   end
 
+  @doc """
+  Due to a bug in httpc, POST, PATCH and PUT requests will fail, if the body is empty
+
+  This function will ensure, that the body param is always set
+
+  ## Parameters
+
+  - request (Map) - Collected request options
+
+  ## Returns
+
+  Map
+  """
+  @spec ensure_body(map()) :: map()
+  def ensure_body(%{body: nil} = request) do
+    %{request | body: ""}
+  end
+
+  def ensure_body(request) do
+    Map.put_new(request, :body, "")
+  end
+
   @doc """
   Handle the response for a Tesla request