Adds support for custom metadata for aws-elixir.

lib/aws_codegen/rest_service.ex

@@ -256,6 +256,9 @@ defmodule AWS.CodeGen.RestService do
       function_name = AWS.CodeGen.Name.to_snake_case(operation)
       request_header_parameters = collect_request_header_parameters(language, api_spec, operation)
 
+      request_headers_parameters =
+        collect_request_headers_parameters(language, api_spec, operation)
+
       is_required = fn param -> param.required end
       required_query_parameters = Enum.filter(query_parameters, is_required)
       required_request_header_parameters = Enum.filter(request_header_parameters, is_required)
@@ -266,7 +269,8 @@ defmodule AWS.CodeGen.RestService do
           "GET" ->
             case language do
               :elixir ->
-                2 + length(request_header_parameters) + length(query_parameters)
+                2 + length(request_header_parameters) + length(request_headers_parameters) +
+                  length(query_parameters)
 
               :erlang ->
                 4 + length(required_request_header_parameters) + length(required_query_parameters)
@@ -295,6 +299,7 @@ defmodule AWS.CodeGen.RestService do
         query_parameters: query_parameters,
         required_query_parameters: required_query_parameters,
         request_header_parameters: request_header_parameters,
+        request_headers_parameters: request_headers_parameters,
         required_request_header_parameters: required_request_header_parameters,
         response_header_parameters:
           collect_response_header_parameters(language, api_spec, operation),
@@ -338,6 +343,10 @@ defmodule AWS.CodeGen.RestService do
     collect_parameters(language, api_spec, operation, "input", "smithy.api#httpHeader")
   end
 
+  defp collect_request_headers_parameters(language, api_spec, operation) do
+    collect_parameters(language, api_spec, operation, "input", "smithy.api#httpPrefixHeaders")
+  end
+
   defp collect_response_header_parameters(language, api_spec, operation) do
     collect_parameters(language, api_spec, operation, "output", "smithy.api#httpHeader")
   end

priv/rest.ex.eex

@@ -123,7 +123,13 @@ def <%= action.function_name %>(%Client{} = client<%= AWS.CodeGen.RestService.fu
         {"<%= parameter.name %>", "<%= parameter.location_name %>"},<% end %>
       ]
       |> Request.build_params(input)<% else %>
-    headers = []<% end %><%= if length(action.query_parameters) > 0 do %>
+    headers = []<% end %><%= if length(action.request_headers_parameters) > 0 do %>
+    {custom_headers, input} =
+      [<%= for parameter <- action.request_headers_parameters do %>
+        {"<%= parameter.name %>", "<%= parameter.location_name %>"},<% end %>
+      ]
+      |> Request.build_params(input)<% else %>
+    custom_headers = []<% end %><%= if length(action.query_parameters) > 0 do %>
     {query_params, input} =
       [<%= for parameter <- action.query_parameters do %>
         {"<%= parameter.name %>", "<%= parameter.location_name %>"},<% end %>
@@ -166,6 +172,6 @@ def <%= action.function_name %>(%Client{} = client<%= AWS.CodeGen.RestService.fu
       meta = metadata()
     <% end %>
 
-    Request.request_rest(client, meta, <%= AWS.CodeGen.RestService.Action.method(action) %>, url_path, query_params, headers, input, options, <%= inspect(action.success_status_code) %>)<% end %>
+    Request.request_rest(client, meta, <%= AWS.CodeGen.RestService.Action.method(action) %>, url_path, query_params, custom_headers ++ headers, input, options, <%= inspect(action.success_status_code) %>)<% end %>
   end<% end %>
 end

test/aws_codegen_test.exs

@@ -14,6 +14,9 @@ defmodule AWS.CodeGenTest do
     }
   }
 
+  @service_spec_custom_headers_file "test/fixtures/apis_specs/dataexchange.json"
+  @service_spec_custom_headers_generated "test/fixtures/generated/data_exchange.ex"
+
   setup do
     service_specs =
       @service_spec_file
@@ -24,7 +27,7 @@ defmodule AWS.CodeGenTest do
   end
 
   describe "render/2" do
-    defp setup_context(language, specs, docs \\ nil) do
+    defp setup_context(language, specs, _docs \\ nil) do
       spec = %AWS.CodeGen.Spec{
         api: specs,
         module_name: "AWS.CloudTrailData",
@@ -37,6 +40,19 @@ defmodule AWS.CodeGenTest do
       RestService.load_context(language, spec, @endpoints_spec)
     end
 
+    defp setup_dataexchange_context(language, specs, _docs \\ nil) do
+      spec = %AWS.CodeGen.Spec{
+        api: specs,
+        module_name: "AWS.DataExchange",
+        filename: "data_exchange.ex",
+        protocol: :rest_json,
+        language: :elixir,
+        shape_name: "com.amazonaws.dataexchange#DataExchange"
+      }
+
+      RestService.load_context(language, spec, @endpoints_spec)
+    end
+
     test "renders the Elixir module with docs", %{specs: specs} do
       context = setup_context(:elixir, specs)
 
@@ -238,6 +254,7 @@ defmodule AWS.CodeGenTest do
                  def put_audit_events(%Client{} = client, input, options \\\\ []) do
                    url_path = \"/PutAuditEvents\"
                    headers = []
+                   custom_headers = []
 
                    {query_params, input} =
                      [
@@ -254,7 +271,7 @@ defmodule AWS.CodeGenTest do
                      :post,
                      url_path,
                      query_params,
-                     headers,
+                     custom_headers ++ headers,
                      input,
                      options,
                      200
@@ -717,6 +734,7 @@ defmodule AWS.CodeGenTest do
                  def put_audit_events(%Client{} = client, input, options \\\\ []) do
                    url_path = \"/PutAuditEvents\"
                    headers = []
+                   custom_headers = []
 
                    {query_params, input} =
                      [
@@ -733,7 +751,7 @@ defmodule AWS.CodeGenTest do
                      :post,
                      url_path,
                      query_params,
-                     headers,
+                     custom_headers ++ headers,
                      input,
                      options,
                      200
@@ -742,5 +760,22 @@ defmodule AWS.CodeGenTest do
                end
                """)
     end
+
+    test "renders the Elixir module with custom headers" do
+      specs_file =
+        @service_spec_custom_headers_file
+        |> File.read!()
+        |> Poison.decode!()
+
+      context = setup_dataexchange_context(:elixir, specs_file)
+
+      result =
+        context
+        |> AWS.CodeGen.render("priv/rest.ex.eex")
+        |> IO.iodata_to_binary()
+
+      generated = File.read!(@service_spec_custom_headers_generated)
+      assert result == generated
+    end
   end
 end