Add merge requests list endpoint for groups

changelogs/unreleased/issue_45082.yml

+---
+title: Add merge requests list endpoint for groups
+merge_request:
+author:
+type: other

doc/api/merge_requests.md

@@ -240,6 +240,112 @@ Parameters:
 ]
 ```
 
+## List group merge requests
+
+Get all merge requests for this group and its subgroups.
+The `state` parameter can be used to get only merge requests with a given state (`opened`, `closed`, or `merged`) or all of them (`all`).
+The pagination parameters `page` and `per_page` can be used to restrict the list of merge requests.
+
+```
+GET /groups/:id/merge_requests
+GET /groups/:id/merge_requests?state=opened
+GET /groups/:id/merge_requests?state=all
+GET /groups/:id/merge_requests?milestone=release
+GET /groups/:id/merge_requests?labels=bug,reproduced
+GET /groups/:id/merge_requests?my_reaction_emoji=star
+```
+
+`group_id` represents the ID of the group which contains the project where the MR resides.
+
+Parameters:
+
+| Attribute           | Type           | Required | Description                                                                                                                    |
+| ------------------- | -------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------ |
+| `id`                | integer        | yes      | The ID of a group                                                                                                           |
+| `state`             | string         | no       | Return all merge requests or just those that are `opened`, `closed`, or `merged`                                               |
+| `order_by`          | string         | no       | Return merge requests ordered by `created_at` or `updated_at` fields. Default is `created_at`                                        |
+| `sort`              | string         | no       | Return merge requests sorted in `asc` or `desc` order. Default is `desc`                                                             |
+| `milestone`         | string         | no       | Return merge requests for a specific milestone                                                                                 |
+| `view`              | string         | no       | If `simple`, returns the `iid`, URL, title, description, and basic state of merge request                                      |
+| `labels`            | string         | no       | Return merge requests matching a comma separated list of labels                                                                |
+| `created_after`     | datetime       | no       | Return merge requests created on or after the given time                                                                       |
+| `created_before`    | datetime       | no       | Return merge requests created on or before the given time                                                                      |
+| `updated_after`     | datetime       | no       | Return merge requests updated on or after the given time                                                                       |
+| `updated_before`    | datetime       | no       | Return merge requests updated on or before the given time                                                                      |
+| `scope`             | string         | no       | Return merge requests for the given scope: `created_by_me`, `assigned_to_me` or `all`.<br>                                     |
+| `author_id`         | integer        | no       | Returns merge requests created by the given user `id` _([Introduced][ce-13060] in GitLab 9.5)_                                 |
+| `assignee_id`       | integer        | no       | Returns merge requests assigned to the given user `id` _([Introduced][ce-13060] in GitLab 9.5)_                                |
+| `my_reaction_emoji` | string         | no       | Return merge requests reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_         |
+| `source_branch`     | string   | no       | Return merge requests with the given source branch                                                                     |
+| `target_branch`     | string   | no       | Return merge requests with the given target branch                                                                     |
+| `search`            | string         | no       | Search merge requests against their `title` and `description`                                                                  |
+
+```json
+[
+  {
+    "id": 1,
+    "iid": 1,
+    "target_branch": "master",
+    "source_branch": "test1",
+    "project_id": 3,
+    "title": "test1",
+    "state": "opened",
+    "created_at": "2017-04-29T08:46:00Z",
+    "updated_at": "2017-04-29T08:46:00Z",
+    "upvotes": 0,
+    "downvotes": 0,
+    "author": {
+      "id": 1,
+      "username": "admin",
+      "email": "admin@example.com",
+      "name": "Administrator",
+      "state": "active",
+      "created_at": "2012-04-29T08:46:00Z"
+    },
+    "assignee": {
+      "id": 1,
+      "username": "admin",
+      "email": "admin@example.com",
+      "name": "Administrator",
+      "state": "active",
+      "created_at": "2012-04-29T08:46:00Z"
+    },
+    "source_project_id": 2,
+    "target_project_id": 3,
+    "labels": [ ],
+    "description": "fixed login page css paddings",
+    "work_in_progress": false,
+    "milestone": {
+      "id": 5,
+      "iid": 1,
+      "project_id": 3,
+      "title": "v2.0",
+      "description": "Assumenda aut placeat expedita exercitationem labore sunt enim earum.",
+      "state": "closed",
+      "created_at": "2015-02-02T19:49:26.013Z",
+      "updated_at": "2015-02-02T19:49:26.013Z",
+      "due_date": null
+    },
+    "merge_when_pipeline_succeeds": true,
+    "merge_status": "can_be_merged",
+    "sha": "8888888888888888888888888888888888888888",
+    "merge_commit_sha": null,
+    "user_notes_count": 1,
+    "changes_count": "1",
+    "should_remove_source_branch": true,
+    "force_remove_source_branch": false,
+    "web_url": "http://example.com/example/example/merge_requests/1",
+    "discussion_locked": false,
+    "time_stats": {
+      "time_estimate": 0,
+      "total_time_spent": 0,
+      "human_time_estimate": null,
+      "human_total_time_spent": null
+    }
+  }
+]
+```
+
 ## Get single MR
 
 Shows information about a single merge request.

lib/api/merge_requests.rb

@@ -59,6 +59,18 @@ module API
         end
       end
 
+      def serializer_options_for(merge_requests)
+        options = { with: Entities::MergeRequestBasic, current_user: current_user }
+
+        if params[:view] == 'simple'
+          options[:with] = Entities::MergeRequestSimple
+        else
+          options[:issuable_metadata] = issuable_meta_data(merge_requests, 'MergeRequest')
+        end
+
+        options
+      end
+
       params :merge_requests_params do
         optional :state, type: String, values: %w[opened closed merged all], default: 'all',
                          desc: 'Return opened, closed, merged, or all merge requests'
@@ -98,16 +110,26 @@ module API
         authenticate! unless params[:scope] == 'all'
         merge_requests = find_merge_requests
 
-        options = { with: Entities::MergeRequestBasic,
-                    current_user: current_user }
+        present merge_requests, serializer_options_for(merge_requests)
+      end
+    end
 
-        if params[:view] == 'simple'
-          options[:with] = Entities::MergeRequestSimple
-        else
-          options[:issuable_metadata] = issuable_meta_data(merge_requests, 'MergeRequest')
-        end
+    params do
+      requires :id, type: String, desc: 'The ID of a group'
+    end
+    resource :groups, requirements: API::PROJECT_ENDPOINT_REQUIREMENTS do
+      desc 'Get a list of group merge requests' do
+        success Entities::MergeRequestBasic
+      end
+      params do
+        use :merge_requests_params
+      end
+      get ":id/merge_requests" do
+        group = find_group!(params[:id])
 
-        present merge_requests, options
+        merge_requests = find_merge_requests(group_id: group.id, include_subgroups: true)
+
+        present merge_requests, serializer_options_for(merge_requests)
       end
     end
 
@@ -159,15 +181,8 @@ module API
 
         merge_requests = find_merge_requests(project_id: user_project.id)
 
-        options = { with: Entities::MergeRequestBasic,
-                    current_user: current_user,
-                    project: user_project }
-
-        if params[:view] == 'simple'
-          options[:with] = Entities::MergeRequestSimple
-        else
-          options[:issuable_metadata] = issuable_meta_data(merge_requests, 'MergeRequest')
-        end
+        options = serializer_options_for(merge_requests)
+        options[:project] = user_project
 
         present merge_requests, options
       end