Remove optional_issue_params method

- move issue_type into whitelisted params

app/services/issues/build_service.rb

@@ -65,7 +65,7 @@ module Issues
     private
 
     def whitelisted_issue_params
-      base_params = [:title, :description, :confidential]
+      base_params = [:title, :description, :confidential, :issue_type]
       admin_params = [:milestone_id]
 
       if can?(current_user, :admin_issue, project)
@@ -75,16 +75,9 @@ module Issues
       end
     end
 
-    def optional_issue_params
-      optional_params = [:issue_type]
-
-      params.slice(*optional_params).reject { |_, v| v.nil? }
-    end
-
     def build_issue_params
       { author: current_user }.merge(issue_params_with_info_from_discussions)
         .merge(whitelisted_issue_params)
-        .merge(optional_issue_params)
     end
   end
 end

spec/services/issues/build_service_spec.rb

@@ -148,15 +148,15 @@ RSpec.describe Issues::BuildService do
       expect(issue.milestone).to be_nil
     end
 
-    context 'with optional params' do
+    context 'setting issue type' do
       it 'sets the issue_type on the issue' do
         issue = build_issue(issue_type: 'incident')
 
         expect(issue.issue_type).to eq('incident')
       end
 
-      it 'defaults to issue if issue_type nil' do
-        issue = build_issue(issue_type: nil)
+      it 'defaults to issue if issue_type not given' do
+        issue = build_issue
 
         expect(issue.issue_type).to eq('issue')
       end