Add filter arguments to MR GraphQL API

Allow filtering MRs by the following arguments:

- Author
- Assignee
- Milestone

app/graphql/resolvers/merge_requests_resolver.rb

@@ -34,6 +34,9 @@ module Resolvers
     argument :merged_before, Types::TimeType,
              required: false,
              description: 'Merge requests merged before this date'
+    argument :milestone_title, GraphQL::STRING_TYPE,
+             required: false,
+             description: 'Title of the milestone'
 
     def self.single
       ::Resolvers::MergeRequestResolver

app/graphql/resolvers/project_merge_requests_resolver.rb

+# frozen_string_literal: true
+
+module Resolvers
+  class ProjectMergeRequestsResolver < MergeRequestsResolver
+    argument :assignee_username, GraphQL::STRING_TYPE,
+             required: false,
+             description: 'Username of the assignee'
+    argument :author_username, GraphQL::STRING_TYPE,
+             required: false,
+             description: 'Username of the author'
+  end
+end

app/graphql/types/project_type.rb

@@ -134,7 +134,7 @@ module Types
           null: true,
           description: 'Merge requests of the project',
           extras: [:lookahead],
-          resolver: Resolvers::MergeRequestsResolver
+          resolver: Resolvers::ProjectMergeRequestsResolver
 
     field :merge_request,
           Types::MergeRequestType,

changelogs/unreleased/235984-add-filters-to-mrs-graphql-api.yml

+---
+title: Filter Merge Requests by author, assignee and milestone in GraphQL
+merge_request: 40265
+author:
+type: added

doc/api/graphql/reference/gitlab_schema.graphql

@@ -11419,6 +11419,16 @@ type Project {
     """
     after: String
 
+    """
+    Username of the assignee
+    """
+    assigneeUsername: String
+
+    """
+    Username of the author
+    """
+    authorUsername: String
+
     """
     Returns the elements in the list that come before the specified cursor.
     """
@@ -11454,6 +11464,11 @@ type Project {
     """
     mergedBefore: Time
 
+    """
+    Title of the milestone
+    """
+    milestoneTitle: String
+
     """
     Array of source branch names. All resolved merge requests will have one of these branches as their source.
     """
@@ -16511,6 +16526,11 @@ type User {
     """
     mergedBefore: Time
 
+    """
+    Title of the milestone
+    """
+    milestoneTitle: String
+
     """
     The global ID of the project the authored merge requests should be in. Incompatible with projectPath.
     """
@@ -16581,6 +16601,11 @@ type User {
     """
     mergedBefore: Time
 
+    """
+    Title of the milestone
+    """
+    milestoneTitle: String
+
     """
     The global ID of the project the authored merge requests should be in. Incompatible with projectPath.
     """

doc/api/graphql/reference/gitlab_schema.json

@@ -33824,6 +33824,36 @@
                   },
                   "defaultValue": null
                 },
+                {
+                  "name": "milestoneTitle",
+                  "description": "Title of the milestone",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "assigneeUsername",
+                  "description": "Username of the assignee",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "authorUsername",
+                  "description": "Username of the author",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
                 {
                   "name": "after",
                   "description": "Returns the elements in the list that come after the specified cursor.",
@@ -48486,6 +48516,16 @@
                   },
                   "defaultValue": null
                 },
+                {
+                  "name": "milestoneTitle",
+                  "description": "Title of the milestone",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
                 {
                   "name": "projectPath",
                   "description": "The full-path of the project the authored merge requests should be in. Incompatible with projectId.",
@@ -48661,6 +48701,16 @@
                   },
                   "defaultValue": null
                 },
+                {
+                  "name": "milestoneTitle",
+                  "description": "Title of the milestone",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
                 {
                   "name": "projectPath",
                   "description": "The full-path of the project the authored merge requests should be in. Incompatible with projectId.",

spec/graphql/resolvers/merge_requests_resolver_spec.rb

@@ -6,7 +6,9 @@ RSpec.describe Resolvers::MergeRequestsResolver do
   include GraphqlHelpers
 
   let_it_be(:project) { create(:project, :repository) }
+  let_it_be(:milestone) { create(:milestone, project: project) }
   let_it_be(:current_user) { create(:user) }
+  let_it_be(:other_user) { create(:user) }
   let_it_be(:common_attrs) { { author: current_user, source_project: project, target_project: project } }
   let_it_be(:merge_request_1) { create(:merge_request, :simple, **common_attrs) }
   let_it_be(:merge_request_2) { create(:merge_request, :rebased, **common_attrs) }
@@ -14,8 +16,10 @@ RSpec.describe Resolvers::MergeRequestsResolver do
   let_it_be(:merge_request_4) { create(:merge_request, :unique_branches, :locked, **common_attrs) }
   let_it_be(:merge_request_5) { create(:merge_request, :simple, :locked, **common_attrs) }
   let_it_be(:merge_request_6) { create(:labeled_merge_request, :unique_branches, labels: create_list(:label, 2), **common_attrs) }
+  let_it_be(:merge_request_with_milestone) { create(:merge_request, :unique_branches, **common_attrs, milestone: milestone) }
   let_it_be(:other_project) { create(:project, :repository) }
   let_it_be(:other_merge_request) { create(:merge_request, source_project: other_project, target_project: other_project) }
+
   let(:iid_1) { merge_request_1.iid }
   let(:iid_2) { merge_request_2.iid }
   let(:other_iid) { other_merge_request.iid }
@@ -32,7 +36,7 @@ RSpec.describe Resolvers::MergeRequestsResolver do
       it 'returns all merge requests' do
         result = resolve_mr(project, {})
 
-        expect(result).to contain_exactly(merge_request_1, merge_request_2, merge_request_3, merge_request_4, merge_request_5, merge_request_6)
+        expect(result).to contain_exactly(merge_request_1, merge_request_2, merge_request_3, merge_request_4, merge_request_5, merge_request_6, merge_request_with_milestone)
       end
 
       it 'returns only merge requests that the current user can see' do
@@ -179,6 +183,20 @@ RSpec.describe Resolvers::MergeRequestsResolver do
       end
     end
 
+    context 'by milestone' do
+      it 'filters merge requests by milestone title' do
+        result = resolve_mr(project, milestone_title: milestone.title)
+
+        expect(result).to eq([merge_request_with_milestone])
+      end
+
+      it 'does not find anything' do
+        result = resolve_mr(project, milestone_title: 'unknown-milestone')
+
+        expect(result).to be_empty
+      end
+    end
+
     describe 'combinations' do
       it 'requires all filters' do
         create(:merge_request, :closed, source_project: project, target_project: project, source_branch: merge_request_4.source_branch)

spec/graphql/resolvers/project_merge_requests_resolver_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Resolvers::ProjectMergeRequestsResolver do
+  include GraphqlHelpers
+
+  let_it_be(:project) { create(:project, :repository) }
+  let_it_be(:current_user) { create(:user) }
+  let_it_be(:other_user) { create(:user) }
+
+  let_it_be(:merge_request_with_author_and_assignee) do
+    create(:merge_request,
+           :unique_branches,
+           source_project: project,
+           target_project: project,
+           author: other_user,
+           assignee: other_user)
+  end
+
+  before do
+    project.add_developer(current_user)
+  end
+
+  context 'by assignee' do
+    it 'filters merge requests by assignee username' do
+      result = resolve_mr(project, assignee_username: other_user.username)
+
+      expect(result).to eq([merge_request_with_author_and_assignee])
+    end
+
+    it 'does not find anything' do
+      result = resolve_mr(project, assignee_username: 'unknown-user')
+
+      expect(result).to be_empty
+    end
+  end
+
+  context 'by author' do
+    it 'filters merge requests by author username' do
+      result = resolve_mr(project, author_username: other_user.username)
+
+      expect(result).to eq([merge_request_with_author_and_assignee])
+    end
+
+    it 'does not find anything' do
+      result = resolve_mr(project, author_username: 'unknown-user')
+
+      expect(result).to be_empty
+    end
+  end
+
+  def resolve_mr(project, args, resolver: described_class, user: current_user)
+    resolve(resolver, obj: project, args: args, ctx: { current_user: user })
+  end
+end

spec/graphql/types/project_type_spec.rb

@@ -59,7 +59,7 @@ RSpec.describe GitlabSchema.types['Project'] do
     subject { described_class.fields['mergeRequests'] }
 
     it { is_expected.to have_graphql_type(Types::MergeRequestType.connection_type) }
-    it { is_expected.to have_graphql_resolver(Resolvers::MergeRequestsResolver) }
+    it { is_expected.to have_graphql_resolver(Resolvers::ProjectMergeRequestsResolver) }
 
     it do
       is_expected.to have_graphql_arguments(:iids,
@@ -72,7 +72,10 @@ RSpec.describe GitlabSchema.types['Project'] do
                                             :first,
                                             :last,
                                             :merged_after,
-                                            :merged_before
+                                            :merged_before,
+                                            :author_username,
+                                            :assignee_username,
+                                            :milestone_title
                                            )
     end
   end