Merge branch 'remove-branch-api' into 'master'

api: expose {should,force}_remove_source_branch

## What does this MR do?

Exposes the `should_remove_source_branch` and `force_remove_source_branch` booleans via the API.

## Are there points in the code the reviewer needs to double check?

I don't think so.

## Why was this MR needed?

See the commit message.

## What are the relevant issue numbers?

N/A

## Screenshots (if relevant)

N/A

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5184

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
 
 v 8.10.0 (unreleased)
+  - Expose {should,force}_remove_source_branch (Ben Boeckel)
   - Fix commit builds API, return all builds for all pipelines for given commit. !4849
   - Replace Haml with Hamlit to make view rendering faster. !3666
   - Refactor repository paths handling to allow multiple git mount points

doc/api/merge_requests.md

@@ -68,7 +68,9 @@ Parameters:
     "merge_when_build_succeeds": true,
     "merge_status": "can_be_merged",
     "subscribed" : false,
-    "user_notes_count": 1
+    "user_notes_count": 1,
+    "should_remove_source_branch": true,
+    "force_remove_source_branch": false
   }
 ]
 ```
@@ -132,7 +134,9 @@ Parameters:
   "merge_when_build_succeeds": true,
   "merge_status": "can_be_merged",
   "subscribed" : true,
-  "user_notes_count": 1
+  "user_notes_count": 1,
+  "should_remove_source_branch": true,
+  "force_remove_source_branch": false
 }
 ```
 
@@ -233,6 +237,8 @@ Parameters:
   "merge_status": "can_be_merged",
   "subscribed" : true,
   "user_notes_count": 1,
+  "should_remove_source_branch": true,
+  "force_remove_source_branch": false,
   "changes": [
     {
     "old_path": "VERSION",
@@ -312,7 +318,9 @@ Parameters:
   "merge_when_build_succeeds": true,
   "merge_status": "can_be_merged",
   "subscribed" : true,
-  "user_notes_count": 0
+  "user_notes_count": 0,
+  "should_remove_source_branch": true,
+  "force_remove_source_branch": false
 }
 ```
 
@@ -383,7 +391,9 @@ Parameters:
   "merge_when_build_succeeds": true,
   "merge_status": "can_be_merged",
   "subscribed" : true,
-  "user_notes_count": 1
+  "user_notes_count": 1,
+  "should_remove_source_branch": true,
+  "force_remove_source_branch": false
 }
 ```
 
@@ -481,7 +491,9 @@ Parameters:
   "merge_when_build_succeeds": true,
   "merge_status": "can_be_merged",
   "subscribed" : true,
-  "user_notes_count": 1
+  "user_notes_count": 1,
+  "should_remove_source_branch": true,
+  "force_remove_source_branch": false
 }
 ```
 
@@ -547,7 +559,9 @@ Parameters:
   "merge_when_build_succeeds": true,
   "merge_status": "can_be_merged",
   "subscribed" : true,
-  "user_notes_count": 1
+  "user_notes_count": 1,
+  "should_remove_source_branch": true,
+  "force_remove_source_branch": false
 }
 ```
 
@@ -866,7 +880,9 @@ Example response:
     "merge_when_build_succeeds": false,
     "merge_status": "unchecked",
     "subscribed": true,
-    "user_notes_count": 7
+    "user_notes_count": 7,
+    "should_remove_source_branch": true,
+    "force_remove_source_branch": false
   },
   "target_url": "https://gitlab.example.com/gitlab-org/gitlab-ci/merge_requests/7",
   "body": "Et voluptas laudantium minus nihil recusandae ut accusamus earum aut non.",

lib/api/entities.rb

@@ -207,6 +207,8 @@ module API
         merge_request.subscribed?(options[:current_user])
       end
       expose :user_notes_count
+      expose :should_remove_source_branch?, as: :should_remove_source_branch
+      expose :force_remove_source_branch?, as: :force_remove_source_branch
     end
 
     class MergeRequestChanges < MergeRequest

spec/requests/api/merge_requests_spec.rb

@@ -138,6 +138,8 @@ describe API::API, api: true  do
       expect(json_response['work_in_progress']).to be_falsy
       expect(json_response['merge_when_build_succeeds']).to be_falsy
       expect(json_response['merge_status']).to eq('can_be_merged')
+      expect(json_response['should_close_merge_request']).to be_falsy
+      expect(json_response['force_close_merge_request']).to be_falsy
     end
 
     it "should return merge_request" do
@@ -147,6 +149,8 @@ describe API::API, api: true  do
       expect(json_response['iid']).to eq(merge_request.iid)
       expect(json_response['work_in_progress']).to eq(false)
       expect(json_response['merge_status']).to eq('can_be_merged')
+      expect(json_response['should_close_merge_request']).to be_falsy
+      expect(json_response['force_close_merge_request']).to be_falsy
     end
 
     it 'should return merge_request by iid' do