Expose Label id to API

[e44da1c] Add Label API expected keys to tests

[ac929c8] Update Label API documentation

4 files changed, 111 insertions, 90 deletions

diff --git a/changelogs/unreleased/add-api-label-id.yml b/changelogs/unreleased/add-api-label-id.yml
new file mode 100644
index 00000000000..3af4f5e677d
--- /dev/null
+++ b/changelogs/unreleased/add-api-label-id.yml
@@ -0,0 +1,4 @@
+---
+title: Expose label IDs in API
+merge_request: 7275
+author: Rares Sfirlogea
diff --git a/doc/api/labels.md b/doc/api/labels.md
index b5242037949..78686fdcad4 100644
--- a/doc/api/labels.md
+++ b/doc/api/labels.md
@@ -20,56 +20,61 @@ Example response:
 
 ```json
 [
-   {
-      "name" : "bug",
-      "color" : "#d9534f",
-      "description": "Bug reported by user",
-      "open_issues_count": 1,
-      "closed_issues_count": 0,
-      "open_merge_requests_count": 1,
-      "subscribed": false,
-      "priority": 10
-   },
-   {
-      "color" : "#d9534f",
-      "name" : "confirmed",
-      "description": "Confirmed issue",
-      "open_issues_count": 2,
-      "closed_issues_count": 5,
-      "open_merge_requests_count": 0,
-      "subscribed": false,
-      "priority": null
-   },
-   {
-      "name" : "critical",
-      "color" : "#d9534f",
-      "description": "Critical issue. Need fix ASAP",
-      "open_issues_count": 1,
-      "closed_issues_count": 3,
-      "open_merge_requests_count": 1,
-      "subscribed": false,
-      "priority": null
-   },
-   {
-      "name" : "documentation",
-      "color" : "#f0ad4e",
-      "description": "Issue about documentation",
-      "open_issues_count": 1,
-      "closed_issues_count": 0,
-      "open_merge_requests_count": 2,
-      "subscribed": false,
-      "priority": null
-   },
-   {
-      "color" : "#5cb85c",
-      "name" : "enhancement",
-      "description": "Enhancement proposal",
-      "open_issues_count": 1,
-      "closed_issues_count": 0,
-      "open_merge_requests_count": 1,
-      "subscribed": false,
-      "priority": null
-   }
+  {
+    "id" : 1,
+    "name" : "bug",
+    "color" : "#d9534f",
+    "description": "Bug reported by user",
+    "open_issues_count": 1,
+    "closed_issues_count": 0,
+    "open_merge_requests_count": 1,
+    "subscribed": false,
+    "priority": 10
+  },
+  {
+    "id" : 4,
+    "color" : "#d9534f",
+    "name" : "confirmed",
+    "description": "Confirmed issue",
+    "open_issues_count": 2,
+    "closed_issues_count": 5,
+    "open_merge_requests_count": 0,
+    "subscribed": false,
+    "priority": null
+  },
+  {
+    "id" : 7,
+    "name" : "critical",
+    "color" : "#d9534f",
+    "description": "Critical issue. Need fix ASAP",
+    "open_issues_count": 1,
+    "closed_issues_count": 3,
+    "open_merge_requests_count": 1,
+    "subscribed": false,
+    "priority": null
+  },
+  {
+    "id" : 8,
+    "name" : "documentation",
+    "color" : "#f0ad4e",
+    "description": "Issue about documentation",
+    "open_issues_count": 1,
+    "closed_issues_count": 0,
+    "open_merge_requests_count": 2,
+    "subscribed": false,
+    "priority": null
+  },
+  {
+    "id" : 9,
+    "color" : "#5cb85c",
+    "name" : "enhancement",
+    "description": "Enhancement proposal",
+    "open_issues_count": 1,
+    "closed_issues_count": 0,
+    "open_merge_requests_count": 1,
+    "subscribed": true,
+    "priority": null
+  }
 ]
 ```
 
@@ -100,13 +105,15 @@ Example response:
 
 ```json
 {
-   "name" : "feature",
-   "color" : "#5843AD",
-   "open_issues_count": 1,
-   "closed_issues_count": 0,
-   "open_merge_requests_count": 1,
-   "description": null,
-   "priority": null
+  "id" : 10,
+  "name" : "feature",
+  "color" : "#5843AD",
+  "description":null,
+  "open_issues_count": 0,
+  "closed_issues_count": 0,
+  "open_merge_requests_count": 0,
+  "subscribed": false,
+  "priority": null
 }
 ```
 
@@ -135,15 +142,15 @@ Example response:
 
 ```json
 {
-   "title" : "feature",
-   "color" : "#5843AD",
-   "description": "New feature proposal",
-   "updated_at" : "2015-11-03T21:22:30.737Z",
-   "template" : false,
-   "project_id" : 1,
-   "created_at" : "2015-11-03T21:22:30.737Z",
-   "id" : 9,
-   "priority": null
+  "id" : 1,
+  "name" : "bug",
+  "color" : "#d9534f",
+  "description": "Bug reported by user",
+  "open_issues_count": 1,
+  "closed_issues_count": 0,
+  "open_merge_requests_count": 1,
+  "subscribed": false,
+  "priority": null
 }
 ```
 
@@ -178,13 +185,15 @@ Example response:
 
 ```json
 {
-   "color" : "#8E44AD",
-   "name" : "docs",
-   "description": "Documentation",
-   "open_issues_count": 1,
-   "closed_issues_count": 0,
-   "open_merge_requests_count": 1,
-   "priority": null
+  "id" : 8,
+  "name" : "docs",
+  "color" : "#8E44AD",
+  "description": "Documentation",
+  "open_issues_count": 1,
+  "closed_issues_count": 0,
+  "open_merge_requests_count": 2,
+  "subscribed": false,
+  "priority": null
 }
 ```
 
@@ -213,14 +222,15 @@ Example response:
 
 ```json
 {
-    "name": "Docs",
-    "color": "#cc0033",
-    "description": "",
-    "open_issues_count": 0,
-    "closed_issues_count": 0,
-    "open_merge_requests_count": 0,
-    "subscribed": true,
-    "priority": null
+  "id" : 1,
+  "name" : "bug",
+  "color" : "#d9534f",
+  "description": "Bug reported by user",
+  "open_issues_count": 1,
+  "closed_issues_count": 0,
+  "open_merge_requests_count": 1,
+  "subscribed": true,
+  "priority": null
 }
 ```
 
@@ -249,13 +259,14 @@ Example response:
 
 ```json
 {
-    "name": "Docs",
-    "color": "#cc0033",
-    "description": "",
-    "open_issues_count": 0,
-    "closed_issues_count": 0,
-    "open_merge_requests_count": 0,
-    "subscribed": false,
-    "priority": null
+  "id" : 1,
+  "name" : "bug",
+  "color" : "#d9534f",
+  "description": "Bug reported by user",
+  "open_issues_count": 1,
+  "closed_issues_count": 0,
+  "open_merge_requests_count": 1,
+  "subscribed": false,
+  "priority": null
 }
 ```
diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index 9dd36ec969e..1942aeea656 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -433,7 +433,7 @@ module API
     end
 
     class LabelBasic < Grape::Entity
-      expose :name, :color, :description
+      expose :id, :name, :color, :description
     end
 
     class Label < LabelBasic
diff --git a/spec/requests/api/labels_spec.rb b/spec/requests/api/labels_spec.rb
index 7e532912d08..2ff90b6deac 100644
--- a/spec/requests/api/labels_spec.rb
+++ b/spec/requests/api/labels_spec.rb
@@ -17,12 +17,18 @@ describe API::API, api: true  do
       group = create(:group)
       group_label = create(:group_label, group: group)
       project.update(group: group)
+      expected_keys = [
+        'id', 'name', 'color', 'description',
+        'open_issues_count', 'closed_issues_count', 'open_merge_requests_count',
+        'subscribed', 'priority'
+      ]
 
       get api("/projects/#{project.id}/labels", user)
 
       expect(response).to have_http_status(200)
       expect(json_response).to be_an Array
       expect(json_response.size).to eq(3)
+      expect(json_response.first.keys).to match_array expected_keys
       expect(json_response.map { |l| l['name'] }).to match_array([group_label.name, priority_label.name, label1.name])
       expect(json_response.last['name']).to eq(label1.name)
       expect(json_response.last['color']).to be_present