Add member: Always return 409 when a member exists

7 files changed, 487 insertions, 12 deletions

diff --git a/changelogs/unreleased/20732_member_exists_409.yml b/changelogs/unreleased/20732_member_exists_409.yml
new file mode 100644
index 00000000000..135647c7ac3
--- /dev/null
+++ b/changelogs/unreleased/20732_member_exists_409.yml
@@ -0,0 +1,4 @@
+---
+title: 'Add member: Always return 409 when a member exists'
+merge_request:
+author:
diff --git a/doc/api/v3_to_v4.md b/doc/api/v3_to_v4.md
index 707f0437b7e..7cb83a337f2 100644
--- a/doc/api/v3_to_v4.md
+++ b/doc/api/v3_to_v4.md
@@ -12,3 +12,4 @@ changes are in V4:
 - Endpoints under `projects/merge_request/:id` have been removed (use: `projects/merge_requests/:id`)
 - Project snippets do not return deprecated field `expires_at`
 - Endpoints under `projects/:id/keys` have been removed (use `projects/:id/deploy_keys`)
+- Status 409 returned for POST `project/:id/members` when a member already exists
diff --git a/lib/api/api.rb b/lib/api/api.rb
index eb9792680ff..7ec089b9c29 100644
--- a/lib/api/api.rb
+++ b/lib/api/api.rb
@@ -7,6 +7,7 @@ module API
     version 'v3', using: :path do
       mount ::API::V3::DeployKeys
       mount ::API::V3::Issues
+      mount ::API::V3::Members
       mount ::API::V3::MergeRequests
       mount ::API::V3::Projects
       mount ::API::V3::ProjectSnippets
diff --git a/lib/api/members.rb b/lib/api/members.rb
index d85f1f78cd6..d1d78775c6d 100644
--- a/lib/api/members.rb
+++ b/lib/api/members.rb
@@ -56,16 +56,9 @@ module API
 
           member = source.members.find_by(user_id: params[:user_id])
 
-          # We need this explicit check because `source.add_user` doesn't
-          # currently return the member created so it would return 201 even if
-          # the member already existed...
-          # The `source_type == 'group'` check is to ensure back-compatibility
-          # but 409 behavior should be used for both project and group members in 9.0!
-          conflict!('Member already exists') if source_type == 'group' && member
-
-          unless member
-            member = source.add_user(params[:user_id], params[:access_level], current_user: current_user, expires_at: params[:expires_at])
-          end
+          conflict!('Member already exists') if member
+
+          member = source.add_user(params[:user_id], params[:access_level], current_user: current_user, expires_at: params[:expires_at])
 
           if member.persisted? && member.valid?
             present member.user, with: Entities::Member, member: member
diff --git a/lib/api/v3/members.rb b/lib/api/v3/members.rb
new file mode 100644
index 00000000000..4e6cb2e3c52
--- /dev/null
+++ b/lib/api/v3/members.rb
@@ -0,0 +1,134 @@
+module API
+  module V3
+    class Members < Grape::API
+      include PaginationParams
+
+      before { authenticate! }
+
+      helpers ::API::Helpers::MembersHelpers
+
+      %w[group project].each do |source_type|
+        params do
+          requires :id, type: String, desc: "The #{source_type} ID"
+        end
+        resource source_type.pluralize do
+          desc 'Gets a list of group or project members viewable by the authenticated user.' do
+            success ::API::Entities::Member
+          end
+          params do
+            optional :query, type: String, desc: 'A query string to search for members'
+            use :pagination
+          end
+          get ":id/members" do
+            source = find_source(source_type, params[:id])
+
+            users = source.users
+            users = users.merge(User.search(params[:query])) if params[:query]
+
+            present paginate(users), with: ::API::Entities::Member, source: source
+          end
+
+          desc 'Gets a member of a group or project.' do
+            success ::API::Entities::Member
+          end
+          params do
+            requires :user_id, type: Integer, desc: 'The user ID of the member'
+          end
+          get ":id/members/:user_id" do
+            source = find_source(source_type, params[:id])
+
+            members = source.members
+            member = members.find_by!(user_id: params[:user_id])
+
+            present member.user, with: ::API::Entities::Member, member: member
+          end
+
+          desc 'Adds a member to a group or project.' do
+            success ::API::Entities::Member
+          end
+          params do
+            requires :user_id, type: Integer, desc: 'The user ID of the new member'
+            requires :access_level, type: Integer, desc: 'A valid access level (defaults: `30`, developer access level)'
+            optional :expires_at, type: DateTime, desc: 'Date string in the format YEAR-MONTH-DAY'
+          end
+          post ":id/members" do
+            source = find_source(source_type, params[:id])
+            authorize_admin_source!(source_type, source)
+
+            member = source.members.find_by(user_id: params[:user_id])
+
+            # We need this explicit check because `source.add_user` doesn't
+            # currently return the member created so it would return 201 even if
+            # the member already existed...
+            # The `source_type == 'group'` check is to ensure back-compatibility
+            # but 409 behavior should be used for both project and group members in 9.0!
+            conflict!('Member already exists') if source_type == 'group' && member
+
+            unless member
+              member = source.add_user(params[:user_id], params[:access_level], current_user: current_user, expires_at: params[:expires_at])
+            end
+            if member.persisted? && member.valid?
+              present member.user, with: ::API::Entities::Member, member: member
+            else
+              # This is to ensure back-compatibility but 400 behavior should be used
+              # for all validation errors in 9.0!
+              render_api_error!('Access level is not known', 422) if member.errors.key?(:access_level)
+              render_validation_error!(member)
+            end
+          end
+
+          desc 'Updates a member of a group or project.' do
+            success ::API::Entities::Member
+          end
+          params do
+            requires :user_id, type: Integer, desc: 'The user ID of the new member'
+            requires :access_level, type: Integer, desc: 'A valid access level'
+            optional :expires_at, type: DateTime, desc: 'Date string in the format YEAR-MONTH-DAY'
+          end
+          put ":id/members/:user_id" do
+            source = find_source(source_type, params[:id])
+            authorize_admin_source!(source_type, source)
+
+            member = source.members.find_by!(user_id: params[:user_id])
+            attrs = attributes_for_keys [:access_level, :expires_at]
+
+            if member.update_attributes(attrs)
+              present member.user, with: ::API::Entities::Member, member: member
+            else
+              # This is to ensure back-compatibility but 400 behavior should be used
+              # for all validation errors in 9.0!
+              render_api_error!('Access level is not known', 422) if member.errors.key?(:access_level)
+              render_validation_error!(member)
+            end
+          end
+
+          desc 'Removes a user from a group or project.'
+          params do
+            requires :user_id, type: Integer, desc: 'The user ID of the member'
+          end
+          delete ":id/members/:user_id" do
+            source = find_source(source_type, params[:id])
+
+            # This is to ensure back-compatibility but find_by! should be used
+            # in that casse in 9.0!
+            member = source.members.find_by(user_id: params[:user_id])
+
+            # This is to ensure back-compatibility but this should be removed in
+            # favor of find_by! in 9.0!
+            not_found!("Member: user_id:#{params[:user_id]}") if source_type == 'group' && member.nil?
+
+            # This is to ensure back-compatibility but 204 behavior should be used
+            # for all DELETE endpoints in 9.0!
+            if member.nil?
+              { message: "Access revoked", id: params[:user_id].to_i }
+            else
+              ::Members::DestroyService.new(source, current_user, declared_params).execute
+
+              present member.user, with: ::API::Entities::Member, member: member
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/requests/api/members_spec.rb b/spec/requests/api/members_spec.rb
index 9892e014cb9..3e9bcfd1a60 100644
--- a/spec/requests/api/members_spec.rb
+++ b/spec/requests/api/members_spec.rb
@@ -145,11 +145,11 @@ describe API::Members, api: true  do
         end
       end
 
-      it "returns #{source_type == 'project' ? 201 : 409} if member already exists" do
+      it "returns 409 if member already exists" do
         post api("/#{source_type.pluralize}/#{source.id}/members", master),
              user_id: master.id, access_level: Member::MASTER
 
-        expect(response).to have_http_status(source_type == 'project' ? 201 : 409)
+        expect(response).to have_http_status(409)
       end
 
       it 'returns 400 when user_id is not given' do
diff --git a/spec/requests/api/v3/members_spec.rb b/spec/requests/api/v3/members_spec.rb
new file mode 100644
index 00000000000..28c3ca03960
--- /dev/null
+++ b/spec/requests/api/v3/members_spec.rb
@@ -0,0 +1,342 @@
+require 'spec_helper'
+
+describe API::Members, api: true  do
+  include ApiHelpers
+
+  let(:master) { create(:user) }
+  let(:developer) { create(:user) }
+  let(:access_requester) { create(:user) }
+  let(:stranger) { create(:user) }
+
+  let(:project) do
+    create(:empty_project, :public, :access_requestable, creator_id: master.id, namespace: master.namespace) do |project|
+      project.team << [developer, :developer]
+      project.team << [master, :master]
+      project.request_access(access_requester)
+    end
+  end
+
+  let!(:group) do
+    create(:group, :public, :access_requestable) do |group|
+      group.add_developer(developer)
+      group.add_owner(master)
+      group.request_access(access_requester)
+    end
+  end
+
+  shared_examples 'GET /:sources/:id/members' do |source_type|
+    context "with :sources == #{source_type.pluralize}" do
+      it_behaves_like 'a 404 response when source is private' do
+        let(:route) { get v3_api("/#{source_type.pluralize}/#{source.id}/members", stranger) }
+      end
+
+      %i[master developer access_requester stranger].each do |type|
+        context "when authenticated as a #{type}" do
+          it 'returns 200' do
+            user = public_send(type)
+            get v3_api("/#{source_type.pluralize}/#{source.id}/members", user)
+
+            expect(response).to have_http_status(200)
+            expect(json_response.size).to eq(2)
+            expect(json_response.map { |u| u['id'] }).to match_array [master.id, developer.id]
+          end
+        end
+      end
+
+      it 'does not return invitees' do
+        create(:"#{source_type}_member", invite_token: '123', invite_email: 'test@abc.com', source: source, user: nil)
+
+        get v3_api("/#{source_type.pluralize}/#{source.id}/members", developer)
+
+        expect(response).to have_http_status(200)
+        expect(json_response.size).to eq(2)
+        expect(json_response.map { |u| u['id'] }).to match_array [master.id, developer.id]
+      end
+
+      it 'finds members with query string' do
+        get v3_api("/#{source_type.pluralize}/#{source.id}/members", developer), query: master.username
+
+        expect(response).to have_http_status(200)
+        expect(json_response.count).to eq(1)
+        expect(json_response.first['username']).to eq(master.username)
+      end
+    end
+  end
+
+  shared_examples 'GET /:sources/:id/members/:user_id' do |source_type|
+    context "with :sources == #{source_type.pluralize}" do
+      it_behaves_like 'a 404 response when source is private' do
+        let(:route) { get v3_api("/#{source_type.pluralize}/#{source.id}/members/#{developer.id}", stranger) }
+      end
+
+      context 'when authenticated as a non-member' do
+        %i[access_requester stranger].each do |type|
+          context "as a #{type}" do
+            it 'returns 200' do
+              user = public_send(type)
+              get v3_api("/#{source_type.pluralize}/#{source.id}/members/#{developer.id}", user)
+
+              expect(response).to have_http_status(200)
+              # User attributes
+              expect(json_response['id']).to eq(developer.id)
+              expect(json_response['name']).to eq(developer.name)
+              expect(json_response['username']).to eq(developer.username)
+              expect(json_response['state']).to eq(developer.state)
+              expect(json_response['avatar_url']).to eq(developer.avatar_url)
+              expect(json_response['web_url']).to eq(Gitlab::Routing.url_helpers.user_url(developer))
+
+              # Member attributes
+              expect(json_response['access_level']).to eq(Member::DEVELOPER)
+            end
+          end
+        end
+      end
+    end
+  end
+
+  shared_examples 'POST /:sources/:id/members' do |source_type|
+    context "with :sources == #{source_type.pluralize}" do
+      it_behaves_like 'a 404 response when source is private' do
+        let(:route) do
+          post v3_api("/#{source_type.pluralize}/#{source.id}/members", stranger),
+               user_id: access_requester.id, access_level: Member::MASTER
+        end
+      end
+
+      context 'when authenticated as a non-member or member with insufficient rights' do
+        %i[access_requester stranger developer].each do |type|
+          context "as a #{type}" do
+            it 'returns 403' do
+              user = public_send(type)
+              post v3_api("/#{source_type.pluralize}/#{source.id}/members", user),
+                   user_id: access_requester.id, access_level: Member::MASTER
+
+              expect(response).to have_http_status(403)
+            end
+          end
+        end
+      end
+
+      context 'when authenticated as a master/owner' do
+        context 'and new member is already a requester' do
+          it 'transforms the requester into a proper member' do
+            expect do
+              post v3_api("/#{source_type.pluralize}/#{source.id}/members", master),
+                   user_id: access_requester.id, access_level: Member::MASTER
+
+              expect(response).to have_http_status(201)
+            end.to change { source.members.count }.by(1)
+            expect(source.requesters.count).to eq(0)
+            expect(json_response['id']).to eq(access_requester.id)
+            expect(json_response['access_level']).to eq(Member::MASTER)
+          end
+        end
+
+        it 'creates a new member' do
+          expect do
+            post v3_api("/#{source_type.pluralize}/#{source.id}/members", master),
+                 user_id: stranger.id, access_level: Member::DEVELOPER, expires_at: '2016-08-05'
+
+            expect(response).to have_http_status(201)
+          end.to change { source.members.count }.by(1)
+          expect(json_response['id']).to eq(stranger.id)
+          expect(json_response['access_level']).to eq(Member::DEVELOPER)
+          expect(json_response['expires_at']).to eq('2016-08-05')
+        end
+      end
+
+      it "returns #{source_type == 'project' ? 201 : 409} if member already exists" do
+        post v3_api("/#{source_type.pluralize}/#{source.id}/members", master),
+             user_id: master.id, access_level: Member::MASTER
+
+        expect(response).to have_http_status(source_type == 'project' ? 201 : 409)
+      end
+
+      it 'returns 400 when user_id is not given' do
+        post v3_api("/#{source_type.pluralize}/#{source.id}/members", master),
+             access_level: Member::MASTER
+
+        expect(response).to have_http_status(400)
+      end
+
+      it 'returns 400 when access_level is not given' do
+        post v3_api("/#{source_type.pluralize}/#{source.id}/members", master),
+             user_id: stranger.id
+
+        expect(response).to have_http_status(400)
+      end
+
+      it 'returns 422 when access_level is not valid' do
+        post v3_api("/#{source_type.pluralize}/#{source.id}/members", master),
+             user_id: stranger.id, access_level: 1234
+
+        expect(response).to have_http_status(422)
+      end
+    end
+  end
+
+  shared_examples 'PUT /:sources/:id/members/:user_id' do |source_type|
+    context "with :sources == #{source_type.pluralize}" do
+      it_behaves_like 'a 404 response when source is private' do
+        let(:route) do
+          put v3_api("/#{source_type.pluralize}/#{source.id}/members/#{developer.id}", stranger),
+              access_level: Member::MASTER
+        end
+      end
+
+      context 'when authenticated as a non-member or member with insufficient rights' do
+        %i[access_requester stranger developer].each do |type|
+          context "as a #{type}" do
+            it 'returns 403' do
+              user = public_send(type)
+              put v3_api("/#{source_type.pluralize}/#{source.id}/members/#{developer.id}", user),
+                  access_level: Member::MASTER
+
+              expect(response).to have_http_status(403)
+            end
+          end
+        end
+      end
+
+      context 'when authenticated as a master/owner' do
+        it 'updates the member' do
+          put v3_api("/#{source_type.pluralize}/#{source.id}/members/#{developer.id}", master),
+              access_level: Member::MASTER, expires_at: '2016-08-05'
+
+          expect(response).to have_http_status(200)
+          expect(json_response['id']).to eq(developer.id)
+          expect(json_response['access_level']).to eq(Member::MASTER)
+          expect(json_response['expires_at']).to eq('2016-08-05')
+        end
+      end
+
+      it 'returns 409 if member does not exist' do
+        put v3_api("/#{source_type.pluralize}/#{source.id}/members/123", master),
+            access_level: Member::MASTER
+
+        expect(response).to have_http_status(404)
+      end
+
+      it 'returns 400 when access_level is not given' do
+        put v3_api("/#{source_type.pluralize}/#{source.id}/members/#{developer.id}", master)
+
+        expect(response).to have_http_status(400)
+      end
+
+      it 'returns 422 when access level is not valid' do
+        put v3_api("/#{source_type.pluralize}/#{source.id}/members/#{developer.id}", master),
+            access_level: 1234
+
+        expect(response).to have_http_status(422)
+      end
+    end
+  end
+
+  shared_examples 'DELETE /:sources/:id/members/:user_id' do |source_type|
+    context "with :sources == #{source_type.pluralize}" do
+      it_behaves_like 'a 404 response when source is private' do
+        let(:route) { delete v3_api("/#{source_type.pluralize}/#{source.id}/members/#{developer.id}", stranger) }
+      end
+
+      context 'when authenticated as a non-member or member with insufficient rights' do
+        %i[access_requester stranger].each do |type|
+          context "as a #{type}" do
+            it 'returns 403' do
+              user = public_send(type)
+              delete v3_api("/#{source_type.pluralize}/#{source.id}/members/#{developer.id}", user)
+
+              expect(response).to have_http_status(403)
+            end
+          end
+        end
+      end
+
+      context 'when authenticated as a member and deleting themself' do
+        it 'deletes the member' do
+          expect do
+            delete v3_api("/#{source_type.pluralize}/#{source.id}/members/#{developer.id}", developer)
+
+            expect(response).to have_http_status(200)
+          end.to change { source.members.count }.by(-1)
+        end
+      end
+
+      context 'when authenticated as a master/owner' do
+        context 'and member is a requester' do
+          it "returns #{source_type == 'project' ? 200 : 404}" do
+            expect do
+              delete v3_api("/#{source_type.pluralize}/#{source.id}/members/#{access_requester.id}", master)
+
+              expect(response).to have_http_status(source_type == 'project' ? 200 : 404)
+            end.not_to change { source.requesters.count }
+          end
+        end
+
+        it 'deletes the member' do
+          expect do
+            delete v3_api("/#{source_type.pluralize}/#{source.id}/members/#{developer.id}", master)
+
+            expect(response).to have_http_status(200)
+          end.to change { source.members.count }.by(-1)
+        end
+      end
+
+      it "returns #{source_type == 'project' ? 200 : 404} if member does not exist" do
+        delete v3_api("/#{source_type.pluralize}/#{source.id}/members/123", master)
+
+        expect(response).to have_http_status(source_type == 'project' ? 200 : 404)
+      end
+    end
+  end
+
+  it_behaves_like 'GET /:sources/:id/members', 'project' do
+    let(:source) { project }
+  end
+
+  it_behaves_like 'GET /:sources/:id/members', 'group' do
+    let(:source) { group }
+  end
+
+  it_behaves_like 'GET /:sources/:id/members/:user_id', 'project' do
+    let(:source) { project }
+  end
+
+  it_behaves_like 'GET /:sources/:id/members/:user_id', 'group' do
+    let(:source) { group }
+  end
+
+  it_behaves_like 'POST /:sources/:id/members', 'project' do
+    let(:source) { project }
+  end
+
+  it_behaves_like 'POST /:sources/:id/members', 'group' do
+    let(:source) { group }
+  end
+
+  it_behaves_like 'PUT /:sources/:id/members/:user_id', 'project' do
+    let(:source) { project }
+  end
+
+  it_behaves_like 'PUT /:sources/:id/members/:user_id', 'group' do
+    let(:source) { group }
+  end
+
+  it_behaves_like 'DELETE /:sources/:id/members/:user_id', 'project' do
+    let(:source) { project }
+  end
+
+  it_behaves_like 'DELETE /:sources/:id/members/:user_id', 'group' do
+    let(:source) { group }
+  end
+
+  context 'Adding owner to project' do
+    it 'returns 403' do
+      expect do
+        post v3_api("/projects/#{project.id}/members", master),
+             user_id: stranger.id, access_level: Member::OWNER
+
+        expect(response).to have_http_status(422)
+      end.to change { project.members.count }.by(0)
+    end
+  end
+end