Only require one parameter when updating a Wiki via the API

changelogs/unreleased/39676-wiki-api-problems-on-update-parameters-and-500-error.yml

+---
+title: 'API: Require only one parameter when updating a wiki'
+merge_request: 25191
+author: Robert Schilling
+type: fixed

lib/api/wikis.rb

@@ -11,9 +11,7 @@ module API
         }
       end
 
-      params :wiki_page_params do
-        requires :content, type: String, desc: 'Content of a wiki page'
-        requires :title, type: String, desc: 'Title of a wiki page'
+      params :common_wiki_page_params do
         optional :format,
           type: String,
           values: ProjectWiki::MARKUPS.values.map(&:to_s),
@@ -54,7 +52,9 @@ module API
         success Entities::WikiPage
       end
       params do
-        use :wiki_page_params
+        requires :title, type: String, desc: 'Title of a wiki page'
+        requires :content, type: String, desc: 'Content of a wiki page'
+        use :common_wiki_page_params
       end
       post ':id/wikis' do
         authorize! :create_wiki, user_project
@@ -72,7 +72,10 @@ module API
         success Entities::WikiPage
       end
       params do
-        use :wiki_page_params
+        optional :title, type: String, desc: 'Title of a wiki page'
+        optional :content, type: String, desc: 'Content of a wiki page'
+        use :common_wiki_page_params
+        at_least_one_of :content, :title, :format
       end
       put ':id/wikis/:slug' do
         authorize! :create_wiki, user_project

spec/requests/api/wikis_spec.rb

@@ -100,6 +100,8 @@ describe API::Wikis do
 
   shared_examples_for 'updates wiki page' do
     it 'updates the wiki page' do
+      put(api(url, user), params: payload)
+
       expect(response).to have_gitlab_http_status(200)
       expect(json_response.size).to eq(4)
       expect(json_response.keys).to match_array(expected_keys_with_content)
@@ -107,6 +109,16 @@ describe API::Wikis do
       expect(json_response['slug']).to eq(payload[:title].tr(' ', '-'))
       expect(json_response['title']).to eq(payload[:title])
     end
+
+    [:title, :content, :format].each do |part|
+      it "it updates with wiki with missing #{part}" do
+        payload.delete(part)
+
+        put(api(url, user), params: payload)
+
+        expect(response).to have_gitlab_http_status(200)
+      end
+    end
   end
 
   shared_examples_for '403 Forbidden' do
@@ -528,8 +540,6 @@ describe API::Wikis do
       context 'when user is developer' do
         before do
           project.add_developer(user)
-
-          put(api(url, user), params: payload)
         end
 
         include_examples 'updates wiki page'
@@ -537,6 +547,10 @@ describe API::Wikis do
         context 'when page is not existing' do
           let(:url) { "/projects/#{project.id}/wikis/unknown" }
 
+          before do
+            put(api(url, user), params: payload)
+          end
+
           include_examples '404 Wiki Page Not Found'
         end
       end
@@ -544,8 +558,6 @@ describe API::Wikis do
       context 'when user is maintainer' do
         before do
           project.add_maintainer(user)
-
-          put(api(url, user), params: payload)
         end
 
         include_examples 'updates wiki page'
@@ -553,6 +565,10 @@ describe API::Wikis do
         context 'when page is not existing' do
           let(:url) { "/projects/#{project.id}/wikis/unknown" }
 
+          before do
+            put(api(url, user), params: payload)
+          end
+
           include_examples '404 Wiki Page Not Found'
         end
       end
@@ -572,8 +588,6 @@ describe API::Wikis do
       context 'when user is developer' do
         before do
           project.add_developer(user)
-
-          put(api(url, user), params: payload)
         end
 
         include_examples 'updates wiki page'
@@ -581,6 +595,10 @@ describe API::Wikis do
         context 'when page is not existing' do
           let(:url) { "/projects/#{project.id}/wikis/unknown" }
 
+          before do
+            put(api(url, user), params: payload)
+          end
+
           include_examples '404 Wiki Page Not Found'
         end
       end
@@ -588,8 +606,6 @@ describe API::Wikis do
       context 'when user is maintainer' do
         before do
           project.add_maintainer(user)
-
-          put(api(url, user), params: payload)
         end
 
         include_examples 'updates wiki page'
@@ -597,6 +613,10 @@ describe API::Wikis do
         context 'when page is not existing' do
           let(:url) { "/projects/#{project.id}/wikis/unknown" }
 
+          before do
+            put(api(url, user), params: payload)
+          end
+
           include_examples '404 Wiki Page Not Found'
         end
       end
@@ -605,10 +625,6 @@ describe API::Wikis do
     context 'when wiki belongs to a group project' do
       let(:project) { create(:project, :wiki_repo, namespace: group) }
 
-      before do
-        put(api(url, user), params: payload)
-      end
-
       include_examples 'updates wiki page'
     end
   end