Add support for MRs assigned for review

This is in analogue to authoredMergeRequests and assignedMergeRequests.

Support for this feature is complete at the model and  finder level, and
this change exposes that at the API level.

This supports filtering by review with:
  - User.reviewRequestedMergeRequests
  - User.assignedMergeRequests(reviewer_username:)
  - User.authoredMergeRequests(reviewer_username:)
  - Project.mergeRequests(reviewer_username:)

app/graphql/resolvers/assigned_merge_requests_resolver.rb

@@ -4,6 +4,7 @@ module Resolvers
   class AssignedMergeRequestsResolver < UserMergeRequestsResolverBase
     type ::Types::MergeRequestType.connection_type, null: true
     accept_author
+    accept_reviewer
 
     def user_role
       :assignee

app/graphql/resolvers/authored_merge_requests_resolver.rb

@@ -4,6 +4,7 @@ module Resolvers
   class AuthoredMergeRequestsResolver < UserMergeRequestsResolverBase
     type ::Types::MergeRequestType.connection_type, null: true
     accept_assignee
+    accept_reviewer
 
     def user_role
       :author

app/graphql/resolvers/merge_requests_resolver.rb

@@ -18,6 +18,12 @@ module Resolvers
              description: 'Username of the author'
     end
 
+    def self.accept_reviewer
+      argument :reviewer_username, GraphQL::STRING_TYPE,
+             required: false,
+             description: 'Username of the reviewer'
+    end
+
     argument :iids, [GraphQL::STRING_TYPE],
               required: false,
               description: 'Array of IIDs of merge requests, for example `[1, 2]`'

app/graphql/resolvers/project_merge_requests_resolver.rb

@@ -5,5 +5,6 @@ module Resolvers
     type ::Types::MergeRequestType.connection_type, null: true
     accept_assignee
     accept_author
+    accept_reviewer
   end
 end

app/graphql/resolvers/review_requested_merge_requests_resolver.rb

+# frozen_string_literal: true
+
+module Resolvers
+  class ReviewRequestedMergeRequestsResolver < UserMergeRequestsResolverBase
+    type ::Types::MergeRequestType.connection_type, null: true
+    accept_author
+    accept_assignee
+
+    def user_role
+      :reviewer
+    end
+  end
+end

app/graphql/types/user_type.rb

@@ -48,13 +48,16 @@ module Types
           description: 'Projects starred by the user',
           resolver: Resolvers::UserStarredProjectsResolver
 
-    # Merge request field: MRs can be either authored or assigned:
+    # Merge request field: MRs can be authored, assigned, or assigned-for-review:
     field :authored_merge_requests,
           resolver: Resolvers::AuthoredMergeRequestsResolver,
           description: 'Merge Requests authored by the user'
     field :assigned_merge_requests,
           resolver: Resolvers::AssignedMergeRequestsResolver,
           description: 'Merge Requests assigned to the user'
+    field :review_requested_merge_requests,
+          resolver: Resolvers::ReviewRequestedMergeRequestsResolver,
+          description: 'Merge Requests assigned to the user for review'
 
     field :snippets,
           Types::SnippetType.connection_type,

changelogs/unreleased/ajk-gql-reviewer-merge-requests.yml

+---
+title: Support merge requests filtered by reviewer in GraphQL API
+merge_request: 49464
+author:
+type: changed

doc/api/graphql/reference/gitlab_schema.graphql

@@ -16948,6 +16948,11 @@ type Project {
     """
     milestoneTitle: String
 
+    """
+    Username of the reviewer
+    """
+    reviewerUsername: String
+
     """
     Sort merge requests by this criteria
     """
@@ -23909,6 +23914,11 @@ type User {
     """
     projectPath: String
 
+    """
+    Username of the reviewer
+    """
+    reviewerUsername: String
+
     """
     Sort merge requests by this criteria
     """
@@ -23994,6 +24004,11 @@ type User {
     """
     projectPath: String
 
+    """
+    Username of the reviewer
+    """
+    reviewerUsername: String
+
     """
     Sort merge requests by this criteria
     """
@@ -24100,6 +24115,96 @@ type User {
   """
   publicEmail: String
 
+  """
+  Merge Requests assigned to the user for review
+  """
+  reviewRequestedMergeRequests(
+    """
+    Returns the elements in the list that come after the specified cursor.
+    """
+    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.
+    """
+    before: String
+
+    """
+    Returns the first _n_ elements from the list.
+    """
+    first: Int
+
+    """
+    Array of IIDs of merge requests, for example `[1, 2]`
+    """
+    iids: [String!]
+
+    """
+    Array of label names. All resolved merge requests will have all of these labels.
+    """
+    labels: [String!]
+
+    """
+    Returns the last _n_ elements from the list.
+    """
+    last: Int
+
+    """
+    Merge requests merged after this date
+    """
+    mergedAfter: Time
+
+    """
+    Merge requests merged before this date
+    """
+    mergedBefore: Time
+
+    """
+    Title of the milestone
+    """
+    milestoneTitle: String
+
+    """
+    The global ID of the project the authored merge requests should be in. Incompatible with projectPath.
+    """
+    projectId: ProjectID
+
+    """
+    The full-path of the project the authored merge requests should be in. Incompatible with projectId.
+    """
+    projectPath: String
+
+    """
+    Sort merge requests by this criteria
+    """
+    sort: MergeRequestSort = created_desc
+
+    """
+    Array of source branch names. All resolved merge requests will have one of these branches as their source.
+    """
+    sourceBranches: [String!]
+
+    """
+    A merge request state. If provided, all resolved merge requests will have this state.
+    """
+    state: MergeRequestState
+
+    """
+    Array of target branch names. All resolved merge requests will have one of these branches as their target.
+    """
+    targetBranches: [String!]
+  ): MergeRequestConnection
+
   """
   Snippets authored by the user
   """

doc/api/graphql/reference/gitlab_schema.json

@@ -49877,6 +49877,16 @@
                   },
                   "defaultValue": null
                 },
+                {
+                  "name": "reviewerUsername",
+                  "description": "Username of the reviewer",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
                 {
                   "name": "after",
                   "description": "Returns the elements in the list that come after the specified cursor.",
@@ -69727,6 +69737,16 @@
                   },
                   "defaultValue": null
                 },
+                {
+                  "name": "reviewerUsername",
+                  "description": "Username of the reviewer",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
                 {
                   "name": "after",
                   "description": "Returns the elements in the list that come after the specified cursor.",
@@ -69932,6 +69952,16 @@
                   },
                   "defaultValue": null
                 },
+                {
+                  "name": "reviewerUsername",
+                  "description": "Username of the reviewer",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
                 {
                   "name": "after",
                   "description": "Returns the elements in the list that come after the specified cursor.",
@@ -70193,6 +70223,221 @@
               "isDeprecated": false,
               "deprecationReason": null
             },
+            {
+              "name": "reviewRequestedMergeRequests",
+              "description": "Merge Requests assigned to the user for review",
+              "args": [
+                {
+                  "name": "iids",
+                  "description": "Array of IIDs of merge requests, for example `[1, 2]`",
+                  "type": {
+                    "kind": "LIST",
+                    "name": null,
+                    "ofType": {
+                      "kind": "NON_NULL",
+                      "name": null,
+                      "ofType": {
+                        "kind": "SCALAR",
+                        "name": "String",
+                        "ofType": null
+                      }
+                    }
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "sourceBranches",
+                  "description": "Array of source branch names. All resolved merge requests will have one of these branches as their source.",
+                  "type": {
+                    "kind": "LIST",
+                    "name": null,
+                    "ofType": {
+                      "kind": "NON_NULL",
+                      "name": null,
+                      "ofType": {
+                        "kind": "SCALAR",
+                        "name": "String",
+                        "ofType": null
+                      }
+                    }
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "targetBranches",
+                  "description": "Array of target branch names. All resolved merge requests will have one of these branches as their target.",
+                  "type": {
+                    "kind": "LIST",
+                    "name": null,
+                    "ofType": {
+                      "kind": "NON_NULL",
+                      "name": null,
+                      "ofType": {
+                        "kind": "SCALAR",
+                        "name": "String",
+                        "ofType": null
+                      }
+                    }
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "state",
+                  "description": "A merge request state. If provided, all resolved merge requests will have this state.",
+                  "type": {
+                    "kind": "ENUM",
+                    "name": "MergeRequestState",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "labels",
+                  "description": "Array of label names. All resolved merge requests will have all of these labels.",
+                  "type": {
+                    "kind": "LIST",
+                    "name": null,
+                    "ofType": {
+                      "kind": "NON_NULL",
+                      "name": null,
+                      "ofType": {
+                        "kind": "SCALAR",
+                        "name": "String",
+                        "ofType": null
+                      }
+                    }
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "mergedAfter",
+                  "description": "Merge requests merged after this date",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "Time",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "mergedBefore",
+                  "description": "Merge requests merged before this date",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "Time",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "milestoneTitle",
+                  "description": "Title of the milestone",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "sort",
+                  "description": "Sort merge requests by this criteria",
+                  "type": {
+                    "kind": "ENUM",
+                    "name": "MergeRequestSort",
+                    "ofType": null
+                  },
+                  "defaultValue": "created_desc"
+                },
+                {
+                  "name": "projectPath",
+                  "description": "The full-path of the project the authored merge requests should be in. Incompatible with projectId.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "projectId",
+                  "description": "The global ID of the project the authored merge requests should be in. Incompatible with projectPath.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "ProjectID",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "authorUsername",
+                  "description": "Username of the author",
+                  "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": "after",
+                  "description": "Returns the elements in the list that come after the specified cursor.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "before",
+                  "description": "Returns the elements in the list that come before the specified cursor.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "first",
+                  "description": "Returns the first _n_ elements from the list.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "Int",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "last",
+                  "description": "Returns the last _n_ elements from the list.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "Int",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                }
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "MergeRequestConnection",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
             {
               "name": "snippets",
               "description": "Snippets authored by the user",

doc/api/graphql/reference/index.md

@@ -3643,6 +3643,7 @@ Autogenerated return type of UpdateSnippet.
 | `name` | String! | Human-readable name of the user |
 | `projectMemberships` | ProjectMemberConnection | Project memberships of the user |
 | `publicEmail` | String | User's public email |
+| `reviewRequestedMergeRequests` | MergeRequestConnection | Merge Requests assigned to the user for review |
 | `snippets` | SnippetConnection | Snippets authored by the user |
 | `starredProjects` | ProjectConnection | Projects starred by the user |
 | `state` | UserState! | State of the user |

spec/graphql/resolvers/project_merge_requests_resolver_spec.rb

@@ -8,14 +8,16 @@ RSpec.describe Resolvers::ProjectMergeRequestsResolver do
   let_it_be(:project) { create(:project, :repository) }
   let_it_be(:current_user) { create(:user) }
   let_it_be(:other_user) { create(:user) }
+  let_it_be(:reviewer) { create(:user) }
 
-  let_it_be(:merge_request_with_author_and_assignee) do
+  let_it_be(:merge_request) do
     create(:merge_request,
            :unique_branches,
            source_project: project,
            target_project: project,
            author: other_user,
-           assignee: other_user)
+           assignee: other_user,
+           reviewers: [reviewer])
   end
 
   before do
@@ -26,7 +28,7 @@ RSpec.describe Resolvers::ProjectMergeRequestsResolver 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])
+      expect(result).to eq([merge_request])
     end
 
     it 'does not find anything' do
@@ -40,7 +42,7 @@ RSpec.describe Resolvers::ProjectMergeRequestsResolver 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])
+      expect(result).to eq([merge_request])
     end
 
     it 'does not find anything' do
@@ -50,6 +52,20 @@ RSpec.describe Resolvers::ProjectMergeRequestsResolver do
     end
   end
 
+  context 'by reviewer' do
+    it 'filters merge requests by reviewer username' do
+      result = resolve_mr(project, reviewer_username: reviewer.username)
+
+      expect(result).to eq([merge_request])
+    end
+
+    it 'does not find anything' do
+      result = resolve_mr(project, reviewer_username: 'unknown-user')
+
+      expect(result).to be_empty
+    end
+  end
+
   def resolve_mr(project, resolver: described_class, user: current_user, **args)
     resolve(resolver, obj: project, args: args, ctx: { current_user: user })
   end

spec/graphql/types/project_type_spec.rb

@@ -79,6 +79,7 @@ RSpec.describe GitlabSchema.types['Project'] do
                                             :merged_before,
                                             :author_username,
                                             :assignee_username,
+                                            :reviewer_username,
                                             :milestone_title,
                                             :sort
                                            )

spec/graphql/types/user_type_spec.rb

@@ -25,6 +25,7 @@ RSpec.describe GitlabSchema.types['User'] do
       location
       authoredMergeRequests
       assignedMergeRequests
+      reviewRequestedMergeRequests
       groupMemberships
       groupCount
       projectMemberships

spec/requests/api/graphql/user_query_spec.rb

@@ -58,9 +58,25 @@ RSpec.describe 'getting user information' do
              source_project: project_b, author: user)
     end
 
+    let_it_be(:reviewed_mr) do
+      create(:merge_request, :unique_branches, :unique_author,
+             source_project: project_a, reviewers: [user])
+    end
+
+    let_it_be(:reviewed_mr_b) do
+      create(:merge_request, :unique_branches, :unique_author,
+             source_project: project_b, reviewers: [user])
+    end
+
+    let_it_be(:reviewed_mr_c) do
+      create(:merge_request, :unique_branches, :unique_author,
+             source_project: project_b, reviewers: [user])
+    end
+
     let(:current_user) { authorised_user }
     let(:authored_mrs) { graphql_data_at(:user, :authored_merge_requests, :nodes) }
     let(:assigned_mrs) { graphql_data_at(:user, :assigned_merge_requests, :nodes) }
+    let(:reviewed_mrs) { graphql_data_at(:user, :review_requested_merge_requests, :nodes) }
     let(:user_params) { { username: user.username } }
 
     before do
@@ -157,6 +173,23 @@ RSpec.describe 'getting user information' do
               )
             end
           end
+
+          context 'filtering by reviewer' do
+            let(:reviewer) { create(:user) }
+            let(:mr_args) { { reviewer_username: reviewer.username } }
+
+            it 'finds the assigned mrs' do
+              assigned_mr_b.reviewers << reviewer
+              assigned_mr_c.reviewers << reviewer
+
+              post_graphql(query, current_user: current_user)
+
+              expect(assigned_mrs).to contain_exactly(
+                a_hash_including('id' => global_id_of(assigned_mr_b)),
+                a_hash_including('id' => global_id_of(assigned_mr_c))
+              )
+            end
+          end
         end
 
         context 'the current user does not have access' do
@@ -168,6 +201,95 @@ RSpec.describe 'getting user information' do
         end
       end
 
+      describe 'reviewRequestedMergeRequests' do
+        let(:user_fields) do
+          query_graphql_field(:review_requested_merge_requests, mr_args, 'nodes { id }')
+        end
+
+        let(:mr_args) { nil }
+
+        it_behaves_like 'a working graphql query'
+
+        it 'can be found' do
+          expect(reviewed_mrs).to contain_exactly(
+            a_hash_including('id' => global_id_of(reviewed_mr)),
+            a_hash_including('id' => global_id_of(reviewed_mr_b)),
+            a_hash_including('id' => global_id_of(reviewed_mr_c))
+          )
+        end
+
+        context 'applying filters' do
+          context 'filtering by IID without specifying a project' do
+            let(:mr_args) do
+              { iids: [reviewed_mr_b.iid.to_s] }
+            end
+
+            it 'return an argument error that mentions the missing fields' do
+              expect_graphql_errors_to_include(/projectPath/)
+            end
+          end
+
+          context 'filtering by project path and IID' do
+            let(:mr_args) do
+              { project_path: project_b.full_path, iids: [reviewed_mr_b.iid.to_s] }
+            end
+
+            it 'selects the correct MRs' do
+              expect(reviewed_mrs).to contain_exactly(
+                a_hash_including('id' => global_id_of(reviewed_mr_b))
+              )
+            end
+          end
+
+          context 'filtering by project path' do
+            let(:mr_args) do
+              { project_path: project_b.full_path }
+            end
+
+            it 'selects the correct MRs' do
+              expect(reviewed_mrs).to contain_exactly(
+                a_hash_including('id' => global_id_of(reviewed_mr_b)),
+                a_hash_including('id' => global_id_of(reviewed_mr_c))
+              )
+            end
+          end
+
+          context 'filtering by author' do
+            let(:author) { reviewed_mr_b.author }
+            let(:mr_args) { { author_username: author.username } }
+
+            it 'finds the authored mrs' do
+              expect(reviewed_mrs).to contain_exactly(
+                a_hash_including('id' => global_id_of(reviewed_mr_b))
+              )
+            end
+          end
+
+          context 'filtering by assignee' do
+            let(:assignee) { create(:user) }
+            let(:mr_args) { { assignee_username: assignee.username } }
+
+            it 'finds the authored mrs' do
+              reviewed_mr_c.assignees << assignee
+
+              post_graphql(query, current_user: current_user)
+
+              expect(reviewed_mrs).to contain_exactly(
+                a_hash_including('id' => global_id_of(reviewed_mr_c))
+              )
+            end
+          end
+        end
+
+        context 'the current user does not have access' do
+          let(:current_user) { unauthorized_user }
+
+          it 'cannot be found' do
+            expect(reviewed_mrs).to be_empty
+          end
+        end
+      end
+
       describe 'authoredMergeRequests' do
         let(:user_fields) do
           query_graphql_field(:authored_merge_requests, mr_args, 'nodes { id }')
@@ -213,6 +335,23 @@ RSpec.describe 'getting user information' do
             end
           end
 
+          context 'filtering by reviewer' do
+            let(:reviewer) { create(:user) }
+            let(:mr_args) { { reviewer_username: reviewer.username } }
+
+            it 'finds the assigned mrs' do
+              authored_mr_b.reviewers << reviewer
+              authored_mr_c.reviewers << reviewer
+
+              post_graphql(query, current_user: current_user)
+
+              expect(authored_mrs).to contain_exactly(
+                a_hash_including('id' => global_id_of(authored_mr_b)),
+                a_hash_including('id' => global_id_of(authored_mr_c))
+              )
+            end
+          end
+
           context 'filtering by project path and IID' do
             let(:mr_args) do
               { project_path: project_b.full_path, iids: [authored_mr_b.iid.to_s] }