Add id based filtering to projects API

This adds two new filters to the projects endpoint. It is a preparation
for keyset pagination on the id column - so why not implement this as a
standard filtering option if you have to support it anyways?

app/finders/projects_finder.rb

@@ -110,7 +110,10 @@ class ProjectsFinder < UnionFinder
 
   # rubocop: disable CodeReuse/ActiveRecord
   def by_ids(items)
-    project_ids_relation ? items.where(id: project_ids_relation) : items
+    items = items.where(id: project_ids_relation) if project_ids_relation
+    items = items.where('id > ?', params[:id_after]) if params[:id_after]
+    items = items.where('id < ?', params[:id_before]) if params[:id_before]
+    items
   end
   # rubocop: enable CodeReuse/ActiveRecord
 

changelogs/unreleased/ab-projects-id-filter.yml

+---
+title: Add id_before, id_after filter param to projects API
+merge_request: 19949
+author:
+type: added

doc/api/projects.md

@@ -58,6 +58,8 @@ GET /projects
 | `wiki_checksum_failed`        | boolean | no | **(PREMIUM)** Limit projects where the wiki checksum calculation has failed ([Introduced](https://gitlab.com/gitlab-org/gitlab/merge_requests/6137) in [GitLab Premium](https://about.gitlab.com/pricing/) 11.2) |
 | `repository_checksum_failed`  | boolean | no | **(PREMIUM)** Limit projects where the repository checksum calculation has failed ([Introduced](https://gitlab.com/gitlab-org/gitlab/merge_requests/6137) in [GitLab Premium](https://about.gitlab.com/pricing/) 11.2) |
 | `min_access_level`            | integer | no | Limit by current user minimal [access level](members.md) |
+| `id_after`                    | integer | no | Limit by project id greater than given ) |
+| `id_before`                   | integer | no | Limit by project id less than given ) |
 
 When `simple=true` or the user is unauthenticated this returns something like:
 
@@ -304,6 +306,8 @@ GET /users/:user_id/projects
 | `with_merge_requests_enabled` | boolean | no | Limit by enabled merge requests feature |
 | `with_programming_language` | string | no | Limit by projects which use the given programming language |
 | `min_access_level` | integer | no | Limit by current user minimal [access level](members.md) |
+| `id_after`         | integer | no | Limit by project id greater than given ) |
+| `id_before`        | integer | no | Limit by project id less than given ) |
 
 ```json
 [

lib/api/helpers.rb

@@ -479,6 +479,8 @@ module API
       finder_params[:user] = params.delete(:user) if params[:user]
       finder_params[:custom_attributes] = params[:custom_attributes] if params[:custom_attributes]
       finder_params[:min_access_level] = params[:min_access_level] if params[:min_access_level]
+      finder_params[:id_after] = params[:id_after] if params[:id_after]
+      finder_params[:id_before] = params[:id_before] if params[:id_before]
       finder_params
     end
 

lib/api/projects.rb

@@ -61,6 +61,8 @@ module API
         optional :with_merge_requests_enabled, type: Boolean, default: false, desc: 'Limit by enabled merge requests feature'
         optional :with_programming_language, type: String, desc: 'Limit to repositories which use the given programming language'
         optional :min_access_level, type: Integer, values: Gitlab::Access.all_values, desc: 'Limit by minimum access level of authenticated user'
+        optional :id_after, type: Integer, desc: 'Limit by greater than project id'
+        optional :id_before, type: Integer, desc: 'Limit by less than project id'
 
         use :optional_filter_params_ee
       end

spec/finders/projects_finder_spec.rb

@@ -58,6 +58,22 @@ describe ProjectsFinder, :do_not_mock_admin_mode do
       it { is_expected.to eq([internal_project]) }
     end
 
+    describe 'with id_after' do
+      context 'only returns projects with a project id greater than given' do
+        let(:params) { { id_after: internal_project.id }}
+
+        it { is_expected.to eq([public_project]) }
+      end
+    end
+
+    describe 'with id_before' do
+      context 'only returns projects with a project id less than given' do
+        let(:params) { { id_before: public_project.id }}
+
+        it { is_expected.to eq([internal_project]) }
+      end
+    end
+
     describe 'filter by visibility_level' do
       before do
         private_project.add_maintainer(user)

spec/requests/api/projects_spec.rb

@@ -362,6 +362,22 @@ describe API::Projects do
         end
       end
 
+      context 'and using id_after' do
+        it_behaves_like 'projects response' do
+          let(:filter) { { id_after: project2.id } }
+          let(:current_user) { user }
+          let(:projects) { [public_project, project, project2, project3].select { |p| p.id > project2.id } }
+        end
+      end
+
+      context 'and using id_before' do
+        it_behaves_like 'projects response' do
+          let(:filter) { { id_before: project2.id } }
+          let(:current_user) { user }
+          let(:projects) { [public_project, project, project2, project3].select { |p| p.id < project2.id } }
+        end
+      end
+
       context 'and membership=true' do
         it_behaves_like 'projects response' do
           let(:filter) { { membership: true } }
@@ -848,6 +864,50 @@ describe API::Projects do
       expect(json_response.map { |project| project['id'] }).to contain_exactly(public_project.id)
     end
 
+    context 'and using id_after' do
+      let!(:another_public_project) { create(:project, :public, name: 'another_public_project', creator_id: user4.id, namespace: user4.namespace) }
+
+      it 'only returns projects with id_after filter given' do
+        get api("/users/#{user4.id}/projects?id_after=#{public_project.id}", user)
+
+        expect(response).to have_gitlab_http_status(200)
+        expect(response).to include_pagination_headers
+        expect(json_response).to be_an Array
+        expect(json_response.map { |project| project['id'] }).to contain_exactly(another_public_project.id)
+      end
+
+      it 'returns both projects without a id_after filter' do
+        get api("/users/#{user4.id}/projects", user)
+
+        expect(response).to have_gitlab_http_status(200)
+        expect(response).to include_pagination_headers
+        expect(json_response).to be_an Array
+        expect(json_response.map { |project| project['id'] }).to contain_exactly(public_project.id, another_public_project.id)
+      end
+    end
+
+    context 'and using id_before' do
+      let!(:another_public_project) { create(:project, :public, name: 'another_public_project', creator_id: user4.id, namespace: user4.namespace) }
+
+      it 'only returns projects with id_before filter given' do
+        get api("/users/#{user4.id}/projects?id_before=#{another_public_project.id}", user)
+
+        expect(response).to have_gitlab_http_status(200)
+        expect(response).to include_pagination_headers
+        expect(json_response).to be_an Array
+        expect(json_response.map { |project| project['id'] }).to contain_exactly(public_project.id)
+      end
+
+      it 'returns both projects without a id_before filter' do
+        get api("/users/#{user4.id}/projects", user)
+
+        expect(response).to have_gitlab_http_status(200)
+        expect(response).to include_pagination_headers
+        expect(json_response).to be_an Array
+        expect(json_response.map { |project| project['id'] }).to contain_exactly(public_project.id, another_public_project.id)
+      end
+    end
+
     it 'returns projects filtered by username' do
       get api("/users/#{user4.username}/projects/", user)