Add response in Publish a package file endpoint

Add package file as a response for Publish a package file endpoint.
A new optional attribute select is introduced.
Select can take package_file as an input.

Changelog: changed

doc/user/packages/generic_packages/index.md

@@ -48,6 +48,7 @@ PUT /projects/:id/packages/generic/:package_name/:package_version/:file_name?sta
 | `package_version`  | string          | yes      | The package version. The following regex validates this: `\A(\.?[\w\+-]+\.?)+\z`. You can test your version strings on [Rubular](https://rubular.com/r/aNCV0wG5K14uq8).
 | `file_name`        | string          | yes      | The filename. It can contain only lowercase letters (`a-z`), uppercase letter (`A-Z`), numbers (`0-9`), dots (`.`), hyphens (`-`), or underscores (`_`).
 | `status`           | string          | no       | The package status. It can be `default` (default) or `hidden`. Hidden packages do not appear in the UI or [package API list endpoints](../../../api/packages.md).
+| `select`           | string          | no       | The response payload. By default, the response is empty. Valid values are: `package_file`. `package_file` returns details of the package file record created by this request.
 
 Provide the file context in the request body.
 
@@ -59,7 +60,7 @@ curl --header "PRIVATE-TOKEN: <your_access_token>" \
      "https://gitlab.example.com/api/v4/projects/24/packages/generic/my_package/0.0.1/file.txt?status=hidden"
 ```
 
-Example response:
+Example response without attribute `select`:
 
 ```json
 {
@@ -67,6 +68,34 @@ Example response:
 }
 ```
 
+Example response with attribute `select = package_file`:
+
+```json
+{
+  "id": 1,
+  "package_id": 1,
+  "created_at": "2021-10-12T12:05:23.387Z",
+  "updated_at": "2021-10-12T12:05:23.387Z",
+  "size": 0,
+  "file_store": 1,
+  "file_md5": null,
+  "file_sha1": null,
+  "file_name": "file.txt",
+  "file": {
+    "url": "/6b/86/6b86b273ff34fce19d6b804eff5a3f5747ada4eaa22f1d49c01e52ddb7875b4b/packages/26/files/36/file.txt"
+  },
+  "file_sha256": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
+  "verification_retry_at": null,
+  "verified_at": null,
+  "verification_failure": null,
+  "verification_retry_count": null,
+  "verification_checksum": null,
+  "verification_state": 0,
+  "verification_started_at": null,
+  "new_file_path": null
+}
+```
+
 ### Publishing a package with the same name or version
 
 When you publish a package with the same name and version as an existing package, the new package

lib/api/generic_packages.rb

@@ -54,6 +54,7 @@ module API
             requires :file_name, type: String, desc: 'Package file name', regexp: Gitlab::Regex.generic_package_file_name_regex, file_path: true
             optional :status, type: String, values: ALLOWED_STATUSES, desc: 'Package status'
             requires :file, type: ::API::Validations::Types::WorkhorseFile, desc: 'The package file to be published (generated by Multipart middleware)'
+            optional :select, type: String, values: %w[package_file]
           end
 
           route_setting :authentication, job_token_allowed: true, basic_auth_personal_access_token: true, deploy_token_allowed: true
@@ -65,11 +66,15 @@ module API
             track_package_event('push_package', :generic, project: project, user: current_user, namespace: project.namespace)
 
             create_package_file_params = declared_params.merge(build: current_authenticated_job)
-            ::Packages::Generic::CreatePackageFileService
+            package_file = ::Packages::Generic::CreatePackageFileService
               .new(project, current_user, create_package_file_params)
               .execute
 
-            created!
+            if params[:select] == 'package_file'
+              present package_file
+            else
+              created!
+            end
           rescue ObjectStorage::RemoteStoreError => e
             Gitlab::ErrorTracking.track_exception(e, extra: { file_name: params[:file_name], project_id: project.id })
 

spec/requests/api/generic_packages_spec.rb

@@ -297,6 +297,37 @@ RSpec.describe API::GenericPackages do
           end
         end
 
+        context 'with select' do
+          context 'with a valid value' do
+            context 'package_file' do
+              let(:params) { super().merge(select: 'package_file') }
+
+              it 'returns a package file' do
+                headers = workhorse_headers.merge(auth_header)
+
+                upload_file(params, headers)
+
+                aggregate_failures do
+                  expect(response).to have_gitlab_http_status(:ok)
+                  expect(json_response).to have_key('id')
+                end
+              end
+            end
+          end
+
+          context 'with an invalid value' do
+            let(:params) { super().merge(select: 'invalid_value') }
+
+            it 'returns a package file' do
+              headers = workhorse_headers.merge(auth_header)
+
+              upload_file(params, headers)
+
+              expect(response).to have_gitlab_http_status(:bad_request)
+            end
+          end
+        end
+
         context 'with a status' do
           context 'valid status' do
             let(:params) { super().merge(status: 'hidden') }