Merge branch 'api-subscription-restful' into 'master'

API: Make subscription API more RESTfuL

Closes #28327

See merge request !9325

12 files changed, 190 insertions, 49 deletions

diff --git a/changelogs/unreleased/api-subscription-restful.yml b/changelogs/unreleased/api-subscription-restful.yml
new file mode 100644
index 00000000000..95db470e6c9
--- /dev/null
+++ b/changelogs/unreleased/api-subscription-restful.yml
@@ -0,0 +1,4 @@
+---
+title: 'API: - Make subscription API more RESTful. Use `post ":project_id/:subscribable_type/:subscribable_id/subscribe"` to subscribe and `post ":project_id/:subscribable_type/:subscribable_id/unsubscribe"` to unsubscribe from a resource.'
+merge_request: 9325
+author: Robert Schilling
diff --git a/doc/api/issues.md b/doc/api/issues.md
index f40e0938b0f..6cd701215e9 100644
--- a/doc/api/issues.md
+++ b/doc/api/issues.md
@@ -514,7 +514,7 @@ If the user is already subscribed to the issue, the status code `304`
 is returned.
 
 ```
-POST /projects/:id/issues/:issue_id/subscription
+POST /projects/:id/issues/:issue_id/subscribe
 ```
 
 | Attribute | Type | Required | Description |
@@ -523,7 +523,7 @@ POST /projects/:id/issues/:issue_id/subscription
 | `issue_id` | integer | yes | The ID of a project's issue |
 
 ```bash
-curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/projects/5/issues/93/subscription
+curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/projects/5/issues/93/subscribe
 ```
 
 Example response:
@@ -569,7 +569,7 @@ from it. If the user is not subscribed to the issue, the
 status code `304` is returned.
 
 ```
-DELETE /projects/:id/issues/:issue_id/subscription
+DELETE /projects/:id/issues/:issue_id/unsubscribe
 ```
 
 | Attribute | Type | Required | Description |
@@ -578,7 +578,7 @@ DELETE /projects/:id/issues/:issue_id/subscription
 | `issue_id` | integer | yes | The ID of a project's issue |
 
 ```bash
-curl --request DELETE --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/projects/5/issues/93/subscription
+curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/projects/5/issues/93/unsubscribe
 ```
 
 Example response:
diff --git a/doc/api/labels.md b/doc/api/labels.md
index 863b28c23b7..a1e7eb1a7b1 100644
--- a/doc/api/labels.md
+++ b/doc/api/labels.md
@@ -188,12 +188,12 @@ Example response:
 
 ## Subscribe to a label
 
-Subscribes the authenticated user to a label to receive notifications. 
+Subscribes the authenticated user to a label to receive notifications.
 If the user is already subscribed to the label, the status code `304`
 is returned.
 
 ```
-POST /projects/:id/labels/:label_id/subscription
+POST /projects/:id/labels/:label_id/subscribe
 ```
 
 | Attribute  | Type              | Required | Description                          |
@@ -202,7 +202,7 @@ POST /projects/:id/labels/:label_id/subscription
 | `label_id` | integer or string | yes      | The ID or title of a project's label |
 
 ```bash
-curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/projects/5/labels/1/subscription
+curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/projects/5/labels/1/subscribe
 ```
 
 Example response:
@@ -228,7 +228,7 @@ from it. If the user is not subscribed to the label, the
 status code `304` is returned.
 
 ```
-DELETE /projects/:id/labels/:label_id/subscription
+DELETE /projects/:id/labels/:label_id/unsubscribe
 ```
 
 | Attribute  | Type              | Required | Description                          |
@@ -237,7 +237,7 @@ DELETE /projects/:id/labels/:label_id/subscription
 | `label_id` | integer or string | yes      | The ID or title of a project's label |
 
 ```bash
-curl --request DELETE --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/projects/5/labels/1/subscription
+curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/projects/5/labels/1/unsubscribe
 ```
 
 Example response:
diff --git a/doc/api/merge_requests.md b/doc/api/merge_requests.md
index 6ee377125d6..2a99ae822d7 100644
--- a/doc/api/merge_requests.md
+++ b/doc/api/merge_requests.md
@@ -667,7 +667,7 @@ Subscribes the authenticated user to a merge request to receive notification. If
 status code `304` is returned.
 
 ```
-POST /projects/:id/merge_requests/:merge_request_id/subscription
+POST /projects/:id/merge_requests/:merge_request_id/subscribe
 ```
 
 | Attribute | Type | Required | Description |
@@ -676,7 +676,7 @@ POST /projects/:id/merge_requests/:merge_request_id/subscription
 | `merge_request_id` | integer | yes   | The ID of the merge request |
 
 ```bash
-curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/projects/5/merge_requests/17/subscription
+curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/projects/5/merge_requests/17/subscribe
 ```
 
 Example response:
@@ -741,7 +741,7 @@ notifications from that merge request. If the user is
 not subscribed to the merge request, the status code `304` is returned.
 
 ```
-DELETE /projects/:id/merge_requests/:merge_request_id/subscription
+DELETE /projects/:id/merge_requests/:merge_request_id/unsubscribe
 ```
 
 | Attribute | Type | Required | Description |
@@ -750,7 +750,7 @@ DELETE /projects/:id/merge_requests/:merge_request_id/subscription
 | `merge_request_id` | integer | yes   | The ID of the merge request |
 
 ```bash
-curl --request DELETE --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/projects/5/merge_requests/17/subscription
+curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v3/projects/5/merge_requests/17/unsubscribe
 ```
 
 Example response:
diff --git a/doc/api/v3_to_v4.md b/doc/api/v3_to_v4.md
index 1af124c56b1..2dd8886ab97 100644
--- a/doc/api/v3_to_v4.md
+++ b/doc/api/v3_to_v4.md
@@ -29,4 +29,5 @@ changes are in V4:
 - Return pagination headers for all endpoints that return an array
 - Removed `DELETE projects/:id/deploy_keys/:key_id/disable`. Use `DELETE projects/:id/deploy_keys/:key_id` instead
 - Moved `PUT /users/:id/(block|unblock)` to `POST /users/:id/(block|unblock)`
+- Make subscription API more RESTful. Use `post ":project_id/:subscribable_type/:subscribable_id/subscribe"` to subscribe and `post ":project_id/:subscribable_type/:subscribable_id/unsubscribe"` to unsubscribe from a resource.
 - Labels filter on `projects/:id/issues` and `/issues` now matches only issues containing all labels (i.e.: Logical AND, not OR)
diff --git a/lib/api/api.rb b/lib/api/api.rb
index e729c07f8c3..2e51be9fff3 100644
--- a/lib/api/api.rb
+++ b/lib/api/api.rb
@@ -17,6 +17,7 @@ module API
       mount ::API::V3::Projects
       mount ::API::V3::ProjectSnippets
       mount ::API::V3::Repositories
+      mount ::API::V3::Subscriptions
       mount ::API::V3::SystemHooks
       mount ::API::V3::Tags
       mount ::API::V3::Todos
diff --git a/lib/api/subscriptions.rb b/lib/api/subscriptions.rb
index e11d7537cc9..acf11dbdf26 100644
--- a/lib/api/subscriptions.rb
+++ b/lib/api/subscriptions.rb
@@ -21,7 +21,7 @@ module API
         desc 'Subscribe to a resource' do
           success entity_class
         end
-        post ":id/#{type}/:subscribable_id/subscription" do
+        post ":id/#{type}/:subscribable_id/subscribe" do
           resource = instance_exec(params[:subscribable_id], &finder)
 
           if resource.subscribed?(current_user, user_project)
@@ -35,7 +35,7 @@ module API
         desc 'Unsubscribe from a resource' do
           success entity_class
         end
-        delete ":id/#{type}/:subscribable_id/subscription" do
+        post ":id/#{type}/:subscribable_id/unsubscribe" do
           resource = instance_exec(params[:subscribable_id], &finder)
 
           if !resource.subscribed?(current_user, user_project)
diff --git a/lib/api/v3/subscriptions.rb b/lib/api/v3/subscriptions.rb
new file mode 100644
index 00000000000..02a4157c26e
--- /dev/null
+++ b/lib/api/v3/subscriptions.rb
@@ -0,0 +1,53 @@
+module API
+  module V3
+    class Subscriptions < Grape::API
+      before { authenticate! }
+
+      subscribable_types = {
+        'merge_request' => proc { |id| find_merge_request_with_access(id, :update_merge_request) },
+        'merge_requests' => proc { |id| find_merge_request_with_access(id, :update_merge_request) },
+        'issues' => proc { |id| find_project_issue(id) },
+        'labels' => proc { |id| find_project_label(id) },
+      }
+
+      params do
+        requires :id, type: String, desc: 'The ID of a project'
+        requires :subscribable_id, type: String, desc: 'The ID of a resource'
+      end
+      resource :projects do
+        subscribable_types.each do |type, finder|
+          type_singularized = type.singularize
+          entity_class = ::API::Entities.const_get(type_singularized.camelcase)
+
+          desc 'Subscribe to a resource' do
+            success entity_class
+          end
+          post ":id/#{type}/:subscribable_id/subscription" do
+            resource = instance_exec(params[:subscribable_id], &finder)
+
+            if resource.subscribed?(current_user, user_project)
+              not_modified!
+            else
+              resource.subscribe(current_user, user_project)
+              present resource, with: entity_class, current_user: current_user, project: user_project
+            end
+          end
+
+          desc 'Unsubscribe from a resource' do
+            success entity_class
+          end
+          delete ":id/#{type}/:subscribable_id/subscription" do
+            resource = instance_exec(params[:subscribable_id], &finder)
+
+            if !resource.subscribed?(current_user, user_project)
+              not_modified!
+            else
+              resource.unsubscribe(current_user, user_project)
+              present resource, with: entity_class, current_user: current_user, project: user_project
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/requests/api/issues_spec.rb b/spec/requests/api/issues_spec.rb
index 7a0bd5f9721..56ca4c04e7d 100644
--- a/spec/requests/api/issues_spec.rb
+++ b/spec/requests/api/issues_spec.rb
@@ -1259,55 +1259,55 @@ describe API::Issues, api: true  do
     end
   end
 
-  describe 'POST :id/issues/:issue_id/subscription' do
+  describe 'POST :id/issues/:issue_id/subscribe' do
     it 'subscribes to an issue' do
-      post api("/projects/#{project.id}/issues/#{issue.id}/subscription", user2)
+      post api("/projects/#{project.id}/issues/#{issue.id}/subscribe", user2)
 
       expect(response).to have_http_status(201)
       expect(json_response['subscribed']).to eq(true)
     end
 
     it 'returns 304 if already subscribed' do
-      post api("/projects/#{project.id}/issues/#{issue.id}/subscription", user)
+      post api("/projects/#{project.id}/issues/#{issue.id}/subscribe", user)
 
       expect(response).to have_http_status(304)
     end
 
     it 'returns 404 if the issue is not found' do
-      post api("/projects/#{project.id}/issues/123/subscription", user)
+      post api("/projects/#{project.id}/issues/123/subscribe", user)
 
       expect(response).to have_http_status(404)
     end
 
     it 'returns 404 if the issue is confidential' do
-      post api("/projects/#{project.id}/issues/#{confidential_issue.id}/subscription", non_member)
+      post api("/projects/#{project.id}/issues/#{confidential_issue.id}/subscribe", non_member)
 
       expect(response).to have_http_status(404)
     end
   end
 
-  describe 'DELETE :id/issues/:issue_id/subscription' do
+  describe 'POST :id/issues/:issue_id/unsubscribe' do
     it 'unsubscribes from an issue' do
-      delete api("/projects/#{project.id}/issues/#{issue.id}/subscription", user)
+      post api("/projects/#{project.id}/issues/#{issue.id}/unsubscribe", user)
 
-      expect(response).to have_http_status(200)
+      expect(response).to have_http_status(201)
       expect(json_response['subscribed']).to eq(false)
     end
 
     it 'returns 304 if not subscribed' do
-      delete api("/projects/#{project.id}/issues/#{issue.id}/subscription", user2)
+      post api("/projects/#{project.id}/issues/#{issue.id}/unsubscribe", user2)
 
       expect(response).to have_http_status(304)
     end
 
     it 'returns 404 if the issue is not found' do
-      delete api("/projects/#{project.id}/issues/123/subscription", user)
+      post api("/projects/#{project.id}/issues/123/unsubscribe", user)
 
       expect(response).to have_http_status(404)
     end
 
     it 'returns 404 if the issue is confidential' do
-      delete api("/projects/#{project.id}/issues/#{confidential_issue.id}/subscription", non_member)
+      post api("/projects/#{project.id}/issues/#{confidential_issue.id}/unsubscribe", non_member)
 
       expect(response).to have_http_status(404)
     end
diff --git a/spec/requests/api/labels_spec.rb b/spec/requests/api/labels_spec.rb
index 5d7a76cf3be..566d11bba57 100644
--- a/spec/requests/api/labels_spec.rb
+++ b/spec/requests/api/labels_spec.rb
@@ -318,10 +318,10 @@ describe API::Labels, api: true  do
     end
   end
 
-  describe "POST /projects/:id/labels/:label_id/subscription" do
+  describe "POST /projects/:id/labels/:label_id/subscribe" do
     context "when label_id is a label title" do
       it "subscribes to the label" do
-        post api("/projects/#{project.id}/labels/#{label1.title}/subscription", user)
+        post api("/projects/#{project.id}/labels/#{label1.title}/subscribe", user)
 
         expect(response).to have_http_status(201)
         expect(json_response["name"]).to eq(label1.title)
@@ -331,7 +331,7 @@ describe API::Labels, api: true  do
 
     context "when label_id is a label ID" do
       it "subscribes to the label" do
-        post api("/projects/#{project.id}/labels/#{label1.id}/subscription", user)
+        post api("/projects/#{project.id}/labels/#{label1.id}/subscribe", user)
 
         expect(response).to have_http_status(201)
         expect(json_response["name"]).to eq(label1.title)
@@ -343,7 +343,7 @@ describe API::Labels, api: true  do
       before { label1.subscribe(user, project) }
 
       it "returns 304" do
-        post api("/projects/#{project.id}/labels/#{label1.id}/subscription", user)
+        post api("/projects/#{project.id}/labels/#{label1.id}/subscribe", user)
 
         expect(response).to have_http_status(304)
       end
@@ -351,21 +351,21 @@ describe API::Labels, api: true  do
 
     context "when label ID is not found" do
       it "returns 404 error" do
-        post api("/projects/#{project.id}/labels/1234/subscription", user)
+        post api("/projects/#{project.id}/labels/1234/subscribe", user)
 
         expect(response).to have_http_status(404)
       end
     end
   end
 
-  describe "DELETE /projects/:id/labels/:label_id/subscription" do
+  describe "POST /projects/:id/labels/:label_id/unsubscribe" do
     before { label1.subscribe(user, project) }
 
     context "when label_id is a label title" do
       it "unsubscribes from the label" do
-        delete api("/projects/#{project.id}/labels/#{label1.title}/subscription", user)
+        post api("/projects/#{project.id}/labels/#{label1.title}/unsubscribe", user)
 
-        expect(response).to have_http_status(200)
+        expect(response).to have_http_status(201)
         expect(json_response["name"]).to eq(label1.title)
         expect(json_response["subscribed"]).to be_falsey
       end
@@ -373,9 +373,9 @@ describe API::Labels, api: true  do
 
     context "when label_id is a label ID" do
       it "unsubscribes from the label" do
-        delete api("/projects/#{project.id}/labels/#{label1.id}/subscription", user)
+        post api("/projects/#{project.id}/labels/#{label1.id}/unsubscribe", user)
 
-        expect(response).to have_http_status(200)
+        expect(response).to have_http_status(201)
         expect(json_response["name"]).to eq(label1.title)
         expect(json_response["subscribed"]).to be_falsey
       end
@@ -385,7 +385,7 @@ describe API::Labels, api: true  do
       before { label1.unsubscribe(user, project) }
 
       it "returns 304" do
-        delete api("/projects/#{project.id}/labels/#{label1.id}/subscription", user)
+        post api("/projects/#{project.id}/labels/#{label1.id}/unsubscribe", user)
 
         expect(response).to have_http_status(304)
       end
@@ -393,7 +393,7 @@ describe API::Labels, api: true  do
 
     context "when label ID is not found" do
       it "returns 404 error" do
-        delete api("/projects/#{project.id}/labels/1234/subscription", user)
+        post api("/projects/#{project.id}/labels/1234/unsubscribe", user)
 
         expect(response).to have_http_status(404)
       end
diff --git a/spec/requests/api/merge_requests_spec.rb b/spec/requests/api/merge_requests_spec.rb
index f4dee4a4ca1..c125df8b90b 100644
--- a/spec/requests/api/merge_requests_spec.rb
+++ b/spec/requests/api/merge_requests_spec.rb
@@ -662,22 +662,22 @@ describe API::MergeRequests, api: true  do
     end
   end
 
-  describe 'POST :id/merge_requests/:merge_request_id/subscription' do
+  describe 'POST :id/merge_requests/:merge_request_id/subscribe' do
     it 'subscribes to a merge request' do
-      post api("/projects/#{project.id}/merge_requests/#{merge_request.id}/subscription", admin)
+      post api("/projects/#{project.id}/merge_requests/#{merge_request.id}/subscribe", admin)
 
       expect(response).to have_http_status(201)
       expect(json_response['subscribed']).to eq(true)
     end
 
     it 'returns 304 if already subscribed' do
-      post api("/projects/#{project.id}/merge_requests/#{merge_request.id}/subscription", user)
+      post api("/projects/#{project.id}/merge_requests/#{merge_request.id}/subscribe", user)
 
       expect(response).to have_http_status(304)
     end
 
     it 'returns 404 if the merge request is not found' do
-      post api("/projects/#{project.id}/merge_requests/123/subscription", user)
+      post api("/projects/#{project.id}/merge_requests/123/subscribe", user)
 
       expect(response).to have_http_status(404)
     end
@@ -686,28 +686,28 @@ describe API::MergeRequests, api: true  do
       guest = create(:user)
       project.team << [guest, :guest]
 
-      post api("/projects/#{project.id}/merge_requests/#{merge_request.id}/subscription", guest)
+      post api("/projects/#{project.id}/merge_requests/#{merge_request.id}/subscribe", guest)
 
       expect(response).to have_http_status(403)
     end
   end
 
-  describe 'DELETE :id/merge_requests/:merge_request_id/subscription' do
+  describe 'POST :id/merge_requests/:merge_request_id/unsubscribe' do
     it 'unsubscribes from a merge request' do
-      delete api("/projects/#{project.id}/merge_requests/#{merge_request.id}/subscription", user)
+      post api("/projects/#{project.id}/merge_requests/#{merge_request.id}/unsubscribe", user)
 
-      expect(response).to have_http_status(200)
+      expect(response).to have_http_status(201)
       expect(json_response['subscribed']).to eq(false)
     end
 
     it 'returns 304 if not subscribed' do
-      delete api("/projects/#{project.id}/merge_requests/#{merge_request.id}/subscription", admin)
+      post api("/projects/#{project.id}/merge_requests/#{merge_request.id}/unsubscribe", admin)
 
       expect(response).to have_http_status(304)
     end
 
     it 'returns 404 if the merge request is not found' do
-      post api("/projects/#{project.id}/merge_requests/123/subscription", user)
+      post api("/projects/#{project.id}/merge_requests/123/unsubscribe", user)
 
       expect(response).to have_http_status(404)
     end
@@ -716,7 +716,7 @@ describe API::MergeRequests, api: true  do
       guest = create(:user)
       project.team << [guest, :guest]
 
-      delete api("/projects/#{project.id}/merge_requests/#{merge_request.id}/subscription", guest)
+      post api("/projects/#{project.id}/merge_requests/#{merge_request.id}/unsubscribe", guest)
 
       expect(response).to have_http_status(403)
     end
diff --git a/spec/requests/api/v3/labels_spec.rb b/spec/requests/api/v3/labels_spec.rb
index 18e2c0d40c8..bcb0c6b9449 100644
--- a/spec/requests/api/v3/labels_spec.rb
+++ b/spec/requests/api/v3/labels_spec.rb
@@ -67,4 +67,86 @@ describe API::V3::Labels, api: true  do
       expect(priority_label_response['subscribed']).to be_falsey
     end
   end
+
+  describe "POST /projects/:id/labels/:label_id/subscription" do
+    context "when label_id is a label title" do
+      it "subscribes to the label" do
+        post v3_api("/projects/#{project.id}/labels/#{label1.title}/subscription", user)
+
+        expect(response).to have_http_status(201)
+        expect(json_response["name"]).to eq(label1.title)
+        expect(json_response["subscribed"]).to be_truthy
+      end
+    end
+
+    context "when label_id is a label ID" do
+      it "subscribes to the label" do
+        post v3_api("/projects/#{project.id}/labels/#{label1.id}/subscription", user)
+
+        expect(response).to have_http_status(201)
+        expect(json_response["name"]).to eq(label1.title)
+        expect(json_response["subscribed"]).to be_truthy
+      end
+    end
+
+    context "when user is already subscribed to label" do
+      before { label1.subscribe(user, project) }
+
+      it "returns 304" do
+        post v3_api("/projects/#{project.id}/labels/#{label1.id}/subscription", user)
+
+        expect(response).to have_http_status(304)
+      end
+    end
+
+    context "when label ID is not found" do
+      it "returns 404 error" do
+        post v3_api("/projects/#{project.id}/labels/1234/subscription", user)
+
+        expect(response).to have_http_status(404)
+      end
+    end
+  end
+
+  describe "DELETE /projects/:id/labels/:label_id/subscription" do
+    before { label1.subscribe(user, project) }
+
+    context "when label_id is a label title" do
+      it "unsubscribes from the label" do
+        delete v3_api("/projects/#{project.id}/labels/#{label1.title}/subscription", user)
+
+        expect(response).to have_http_status(200)
+        expect(json_response["name"]).to eq(label1.title)
+        expect(json_response["subscribed"]).to be_falsey
+      end
+    end
+
+    context "when label_id is a label ID" do
+      it "unsubscribes from the label" do
+        delete v3_api("/projects/#{project.id}/labels/#{label1.id}/subscription", user)
+
+        expect(response).to have_http_status(200)
+        expect(json_response["name"]).to eq(label1.title)
+        expect(json_response["subscribed"]).to be_falsey
+      end
+    end
+
+    context "when user is already unsubscribed from label" do
+      before { label1.unsubscribe(user, project) }
+
+      it "returns 304" do
+        delete v3_api("/projects/#{project.id}/labels/#{label1.id}/subscription", user)
+
+        expect(response).to have_http_status(304)
+      end
+    end
+
+    context "when label ID is not found" do
+      it "returns 404 error" do
+        delete v3_api("/projects/#{project.id}/labels/1234/subscription", user)
+
+        expect(response).to have_http_status(404)
+      end
+    end
+  end
 end