fix httpx adapter issues

treating DNS resolution errors as ConnectionFailed; removing multipart header set by the openapi-generated code, as it does not contain boundary, and interferes with the generation from httpx, which appropriately deals with mime-types already

modules/openapi-generator/src/main/resources/ruby-client/api_client_httpx_partial.mustache

@@ -19,7 +19,7 @@
                 Net::HTTP::STATUS_CODES.fetch(response.status, "HTTP Error (#{response.status})")
       rescue HTTPX::TimeoutError
         fail ApiError.new('Connection timed out')
-      rescue HTTPX::ConnectionError
+      rescue HTTPX::ConnectionError, HTTPX::ResolveError
         fail ApiError.new('Connection failed')
       end
 
@@ -73,14 +73,11 @@
       # http form
       if header_params['Content-Type'] == 'application/x-www-form-urlencoded' ||
          header_params['Content-Type'] == 'multipart/form-data'
-        data = { form: form_params }
+        header_params.delete('Content-Type') # httpx takes care of this
+        { form: form_params }
       elsif body
-
-        data = body.is_a?(String) ? { body: body } : { json: body }
-      else
-        data = nil
+        body.is_a?(String) ? { body: body } : { json: body }
       end
-      data
     end
 
     def session

samples/client/echo_api/ruby-httpx/lib/openapi_client/api_client.rb

@@ -65,7 +65,7 @@ def call_api(http_method, path, opts = {})
                 Net::HTTP::STATUS_CODES.fetch(response.status, "HTTP Error (#{response.status})")
       rescue HTTPX::TimeoutError
         fail ApiError.new('Connection timed out')
-      rescue HTTPX::ConnectionError
+      rescue HTTPX::ConnectionError, HTTPX::ResolveError
         fail ApiError.new('Connection failed')
       end
 
@@ -100,13 +100,11 @@ def build_request(http_method, path, opts = {})
         if config.debugging
           config.logger.debug "HTTP request body param ~BEGIN~\n#{req_body}\n~END~\n"
         end
-      else
-        body_params = {}
       end
       req_opts = {
-        :headers => HTTPX::Headers.new(header_params),
-        **body_params
+        :headers => HTTPX::Headers.new(header_params)
       }
+      req_opts.merge!(body_params) if body_params
       req_opts[:params] = query_params if query_params && !query_params.empty?
       session.request(http_method, url, **req_opts)
     end
@@ -121,14 +119,11 @@ def build_request_body(header_params, form_params, body)
       # http form
       if header_params['Content-Type'] == 'application/x-www-form-urlencoded' ||
          header_params['Content-Type'] == 'multipart/form-data'
-        data = { form: form_params }
+        header_params.delete('Content-Type') # httpx takes care of this
+        { form: form_params }
       elsif body
-
-        data = body.is_a?(String) ? { body: body } : { json: body }
-      else
-        data = nil
+        body.is_a?(String) ? { body: body } : { json: body }
       end
-      data
     end
 
     def session

samples/client/petstore/ruby-httpx/lib/petstore/api_client.rb

@@ -65,7 +65,7 @@ def call_api(http_method, path, opts = {})
                 Net::HTTP::STATUS_CODES.fetch(response.status, "HTTP Error (#{response.status})")
       rescue HTTPX::TimeoutError
         fail ApiError.new('Connection timed out')
-      rescue HTTPX::ConnectionError
+      rescue HTTPX::ConnectionError, HTTPX::ResolveError
         fail ApiError.new('Connection failed')
       end
 
@@ -119,14 +119,11 @@ def build_request_body(header_params, form_params, body)
       # http form
       if header_params['Content-Type'] == 'application/x-www-form-urlencoded' ||
          header_params['Content-Type'] == 'multipart/form-data'
-        data = { form: form_params }
+        header_params.delete('Content-Type') # httpx takes care of this
+        { form: form_params }
       elsif body
-
-        data = body.is_a?(String) ? { body: body } : { json: body }
-      else
-        data = nil
+        body.is_a?(String) ? { body: body } : { json: body }
       end
-      data
     end
 
     def session

samples/client/petstore/ruby-httpx/spec/custom/pet_spec.rb

@@ -106,7 +106,7 @@
     it "should fetch a pet object with http info" do
       pet, status_code, headers = @pet_api.get_pet_by_id_with_http_info(@pet_id)
       expect(status_code).to eq(200)
-      expect(headers['Content-Type']).to eq('application/json')
+      expect(headers['content-type']).to eq('application/json')
       expect(pet).to be_a(Petstore::Pet)
       expect(pet.id).to eq(@pet_id)
       expect(pet.name).to eq("RUBY UNIT TESTING")
@@ -123,8 +123,8 @@
         # skip the check as the response contains a timestamp that changes on every response
         # expect(e.message).to eq("Error message: the server returns an error\nHTTP status code: 404\nResponse headers: {\"Date\"=>\"Tue, 26 Feb 2019 04:35:40 GMT\", \"Access-Control-Allow-Origin\"=>\"*\", \"Access-Control-Allow-Methods\"=>\"GET, POST, DELETE, PUT\", \"Access-Control-Allow-Headers\"=>\"Content-Type, api_key, Authorization\", \"Content-Type\"=>\"application/json\", \"Connection\"=>\"close\", \"Server\"=>\"Jetty(9.2.9.v20150224)\"}\nResponse body: {\"code\":1,\"type\":\"error\",\"message\":\"Pet not found\"}")
         expect(e.response_body).to eq('{"code":1,"type":"error","message":"Pet not found"}')
-        expect(e.response_headers).to include('Content-Type')
-        expect(e.response_headers['Content-Type']).to eq('application/json')
+        expect(e.response_headers).to include('content-type')
+        expect(e.response_headers['content-type']).to eq('application/json')
       end
     end