Add API to list merge request diff versions

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

doc/api/merge_requests.md

@@ -894,3 +894,93 @@ Example response:
   "created_at": "2016-07-01T11:14:15.530Z"
 }
 ```
+
+## Get MR diff versions
+
+Get a list of merge request diff versions.
+
+```
+GET /projects/:id/merge_requests/:merge_request_id/versions
+```
+
+Parameters:
+
+- `id` (required) - The ID of a project
+- `merge_request_id` (required) - The ID of MR
+
+
+```json
+[{
+  "id": 110,
+  "head_commit_sha": "33e2ee8579fda5bc36accc9c6fbd0b4fefda9e30",
+  "base_commit_sha": "eeb57dffe83deb686a60a71c16c32f71046868fd",
+  "start_commit_sha": "eeb57dffe83deb686a60a71c16c32f71046868fd",
+  "created_at": "2016-07-26T14:44:48.926Z",
+  "merge_request_id": 105,
+  "state": "collected",
+  "real_size": "1",
+  "commits": [{
+    "id": "33e2ee8579fda5bc36accc9c6fbd0b4fefda9e30",
+    "short_id": "33e2ee85",
+    "title": "Change year to 2018",
+    "author_name": "Administrator",
+    "author_email": "admin@example.com",
+    "created_at": "2016-07-26T17:44:29.000+03:00",
+    "message": "Change year to 2018"
+  }, {
+    "id": "aa24655de48b36335556ac8a3cd8bb521f977cbd",
+    "short_id": "aa24655d",
+    "title": "Update LICENSE",
+    "author_name": "Administrator",
+    "author_email": "admin@example.com",
+    "created_at": "2016-07-25T17:21:53.000+03:00",
+    "message": "Update LICENSE"
+  }, {
+    "id": "3eed087b29835c48015768f839d76e5ea8f07a24",
+    "short_id": "3eed087b",
+    "title": "Add license",
+    "author_name": "Administrator",
+    "author_email": "admin@example.com",
+    "created_at": "2016-07-25T17:21:20.000+03:00",
+    "message": "Add license"
+  }],
+  "diffs": [{
+    "old_path": "LICENSE",
+    "new_path": "LICENSE",
+    "a_mode": "0",
+    "b_mode": "100644",
+    "diff": "--- /dev/null\n+++ b/LICENSE\n@@ -0,0 +1,21 @@\n+The MIT License (MIT)\n+\n+Copyright (c) 2018 Administrator\n+\n+Permission is hereby granted, free of charge, to any person obtaining a copy\n+of this software and associated documentation files (the \"Software\"), to deal\n+in the Software without restriction, including without limitation the rights\n+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell\n+copies of the Software, and to permit persons to whom the Software is\n+furnished to do so, subject to the following conditions:\n+\n+The above copyright notice and this permission notice shall be included in all\n+copies or substantial portions of the Software.\n+\n+THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\n+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,\n+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE\n+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER\n+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,\n+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE\n+SOFTWARE.\n",
+    "new_file": true,
+    "renamed_file": false,
+    "deleted_file": false
+  }]
+}, {
+  "id": 108,
+  "head_commit_sha": "3eed087b29835c48015768f839d76e5ea8f07a24",
+  "base_commit_sha": "eeb57dffe83deb686a60a71c16c32f71046868fd",
+  "start_commit_sha": "eeb57dffe83deb686a60a71c16c32f71046868fd",
+  "created_at": "2016-07-25T14:21:33.028Z",
+  "merge_request_id": 105,
+  "state": "collected",
+  "real_size": "1",
+  "commits": [{
+    "id": "3eed087b29835c48015768f839d76e5ea8f07a24",
+    "short_id": "3eed087b",
+    "title": "Add license",
+    "author_name": "Administrator",
+    "author_email": "admin@example.com",
+    "created_at": "2016-07-25T17:21:20.000+03:00",
+    "message": "Add license"
+  }],
+  "diffs": [{
+    "old_path": "LICENSE",
+    "new_path": "LICENSE",
+    "a_mode": "0",
+    "b_mode": "100644",
+    "diff": "--- /dev/null\n+++ b/LICENSE\n@@ -0,0 +1,21 @@\n+The MIT License (MIT)\n+\n+Copyright (c) 2016 Administrator\n+\n+Permission is hereby granted, free of charge, to any person obtaining a copy\n+of this software and associated documentation files (the \"Software\"), to deal\n+in the Software without restriction, including without limitation the rights\n+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell\n+copies of the Software, and to permit persons to whom the Software is\n+furnished to do so, subject to the following conditions:\n+\n+The above copyright notice and this permission notice shall be included in all\n+copies or substantial portions of the Software.\n+\n+THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\n+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,\n+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE\n+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER\n+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,\n+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE\n+SOFTWARE.\n",
+    "new_file": true,
+    "renamed_file": false,
+    "deleted_file": false
+  }]
+}]
+```

lib/api/api.rb

@@ -67,5 +67,6 @@ module API
     mount ::API::Triggers
     mount ::API::Users
     mount ::API::Variables
+    mount ::API::MergeRequestDiffs
   end
 end

lib/api/entities.rb

@@ -228,6 +228,17 @@ module API
       end
     end
 
+    class MergeRequestDiff < Grape::Entity
+      expose :id, :head_commit_sha, :base_commit_sha, :start_commit_sha,
+        :created_at, :merge_request_id, :state, :real_size
+
+      expose :commits, using: Entities::RepoCommit
+
+      expose :diffs, using: Entities::RepoDiff do |compare, _|
+        compare.diffs(all_diffs: true).to_a
+      end
+    end
+
     class SSHKey < Grape::Entity
       expose :id, :title, :key, :created_at
     end

lib/api/merge_request_diffs.rb

+module API
+  # MergeRequestDiff API
+  class MergeRequestDiffs < Grape::API
+    before { authenticate! }
+
+    resource :projects do
+      # List merge requests diff versions
+      #
+      # Parameters:
+      #   id (required)               - The ID of a project
+      #   merge_request_id (required) - The ID of MR
+      #
+      # Example:
+      #   GET /projects/:id/merge_requests/:merge_request_id/versions
+      #
+      get ":id/merge_requests/:merge_request_id/versions" do
+        merge_request = user_project.merge_requests.
+          find(params[:merge_request_id])
+
+        authorize! :read_merge_request, merge_request
+        present merge_request.merge_request_diffs, with: Entities::MergeRequestDiff
+      end
+    end
+  end
+end

spec/requests/api/merge_request_diffs_spec.rb

+require "spec_helper"
+
+describe API::API, 'MergeRequestDiffs', api: true  do
+  include ApiHelpers
+
+  let!(:user)          { create(:user) }
+  let!(:merge_request) { create(:merge_request, importing: true) }
+  let!(:project)       { merge_request.target_project }
+
+  before do
+    merge_request.merge_request_diffs.create(head_commit_sha: '6f6d7e7ed97bb5f0054f2b1df789b39ca89b6ff9')
+    merge_request.merge_request_diffs.create(head_commit_sha: '5937ac0a7beb003549fc5fd26fc247adbce4a52e')
+    project.team << [user, :master]
+  end
+
+  describe 'GET /projects/:id/merge_requests/:merge_request_id/versions' do
+    context 'valid merge request' do
+      before { get api("/projects/#{project.id}/merge_requests/#{merge_request.id}/versions", user) }
+      let(:merge_request_diff) { merge_request.merge_request_diffs.first }
+
+      it { expect(response.status).to eq 200 }
+      it { expect(json_response.size).to eq(merge_request.merge_request_diffs.size) }
+      it { expect(json_response.first['id']).to eq(merge_request_diff.id) }
+      it { expect(json_response.first['head_commit_sha']).to eq(merge_request_diff.head_commit_sha) }
+    end
+
+    it 'returns a 404 when merge_request_id not found' do
+      get api("/projects/#{project.id}/merge_requests/999/versions", user)
+      expect(response).to have_http_status(404)
+    end
+  end
+end