Unify issues search behavior by always filtering when ALL labels matches26315-unify-labels-filter-behavior

5 files changed, 52 insertions, 19 deletions

diff --git a/changelogs/unreleased/26315-unify-labels-filter-behavior.yml b/changelogs/unreleased/26315-unify-labels-filter-behavior.yml
new file mode 100644
index 00000000000..cd2f40c94fe
--- /dev/null
+++ b/changelogs/unreleased/26315-unify-labels-filter-behavior.yml
@@ -0,0 +1,4 @@
+---
+title: Unify issues search behavior by always filtering when ALL labels matches
+merge_request: 8849
+author:
diff --git a/doc/api/issues.md b/doc/api/issues.md
index 7c0a444d4fa..f40e0938b0f 100644
--- a/doc/api/issues.md
+++ b/doc/api/issues.md
@@ -30,7 +30,7 @@ GET /issues?milestone=1.0.0&state=opened
 | Attribute | Type | Required | Description |
 | --------- | ---- | -------- | ----------- |
 | `state`   | string  | no    | Return all issues or just those that are `opened` or `closed`|
-| `labels`  | string  | no    | Comma-separated list of label names, issues with any of the labels will be returned |
+| `labels`  | string  | no    | Comma-separated list of label names, issues must have all labels to be returned |
 | `milestone` | string| no    | The milestone title |
 | `order_by`| string  | no    | Return requests ordered by `created_at` or `updated_at` fields. Default is `created_at` |
 | `sort`    | string  | no    | Return requests sorted in `asc` or `desc` order. Default is `desc`  |
@@ -188,7 +188,7 @@ GET /projects/:id/issues?milestone=1.0.0&state=opened
 | `id`      | integer | yes   | The ID of a project |
 | `iid`     | integer | no    | Return the issue having the given `iid` |
 | `state`   | string  | no    | Return all issues or just those that are `opened` or `closed`|
-| `labels`  | string  | no    | Comma-separated list of label names, issues with any of the labels will be returned |
+| `labels`  | string  | no    | Comma-separated list of label names, issues must have all labels to be returned |
 | `milestone` | string| no    | The milestone title |
 | `order_by`| string  | no    | Return requests ordered by `created_at` or `updated_at` fields. Default is `created_at` |
 | `sort`    | string  | no    | Return requests sorted in `asc` or `desc` order. Default is `desc`  |
diff --git a/doc/api/v3_to_v4.md b/doc/api/v3_to_v4.md
index 2f82b6e97cc..95a78323242 100644
--- a/doc/api/v3_to_v4.md
+++ b/doc/api/v3_to_v4.md
@@ -27,3 +27,5 @@ 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)`
+- 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/issues.rb b/lib/api/issues.rb
index 90fca20d4fa..2b946bfd349 100644
--- a/lib/api/issues.rb
+++ b/lib/api/issues.rb
@@ -10,17 +10,9 @@ module API
 
         args.delete(:id)
         args[:milestone_title] = args.delete(:milestone)
+        args[:label_name] = args.delete(:labels)
 
-        match_all_labels = args.delete(:match_all_labels)
-        labels = args.delete(:labels)
-        args[:label_name] = labels if match_all_labels
-
-        issues = IssuesFinder.new(current_user, args).execute.inc_notes_with_associations
-
-        # TODO: Remove in 9.0  pass `label_name: args.delete(:labels)` to IssuesFinder
-        if !match_all_labels && labels.present?
-          issues = issues.includes(:labels).where('labels.title' => labels.split(','))
-        end
+        issues = IssuesFinder.new(current_user, args).execute
 
         issues.reorder(args[:order_by] => args[:sort])
       end
@@ -77,7 +69,7 @@ module API
       get ":id/issues" do
         group = find_group!(params[:id])
 
-        issues = find_issues(group_id: group.id, state: params[:state] || 'opened', match_all_labels: true)
+        issues = find_issues(group_id: group.id, state: params[:state] || 'opened')
 
         present paginate(issues), with: Entities::Issue, current_user: current_user
       end
diff --git a/spec/requests/api/issues_spec.rb b/spec/requests/api/issues_spec.rb
index 74ac7955cb8..ece1b43567d 100644
--- a/spec/requests/api/issues_spec.rb
+++ b/spec/requests/api/issues_spec.rb
@@ -117,14 +117,20 @@ describe API::Issues, api: true  do
         expect(json_response.first['labels']).to eq([label.title])
       end
 
-      it 'returns an array of labeled issues when at least one label matches' do
-        get api("/issues?labels=#{label.title},foo,bar", user)
+      it 'returns an array of labeled issues when all labels matches' do
+        label_b = create(:label, title: 'foo', project: project)
+        label_c = create(:label, title: 'bar', project: project)
+
+        create(:label_link, label: label_b, target: issue)
+        create(:label_link, label: label_c, target: issue)
+
+        get api("/issues", user), labels: "#{label.title},#{label_b.title},#{label_c.title}"
 
         expect(response).to have_http_status(200)
         expect(response).to include_pagination_headers
         expect(json_response).to be_an Array
         expect(json_response.length).to eq(1)
-        expect(json_response.first['labels']).to eq([label.title])
+        expect(json_response.first['labels']).to eq([label_c.title, label_b.title, label.title])
       end
 
       it 'returns an empty array if no issue matches labels' do
@@ -356,6 +362,21 @@ describe API::Issues, api: true  do
       expect(json_response.length).to eq(0)
     end
 
+    it 'returns an array of labeled issues when all labels matches' do
+      label_b = create(:label, title: 'foo', project: group_project)
+      label_c = create(:label, title: 'bar', project: group_project)
+
+      create(:label_link, label: label_b, target: group_issue)
+      create(:label_link, label: label_c, target: group_issue)
+
+      get api("#{base_url}", user), labels: "#{group_label.title},#{label_b.title},#{label_c.title}"
+
+      expect(response).to have_http_status(200)
+      expect(json_response).to be_an Array
+      expect(json_response.length).to eq(1)
+      expect(json_response.first['labels']).to eq([label_c.title, label_b.title, group_label.title])
+    end
+
     it 'returns an empty array if no group issue matches labels' do
       get api("#{base_url}?labels=foo,bar", user)
 
@@ -549,14 +570,28 @@ describe API::Issues, api: true  do
       expect(json_response.first['labels']).to eq([label.title])
     end
 
-    it 'returns an array of labeled project issues where all labels match' do
-      get api("#{base_url}/issues?labels=#{label.title},foo,bar", user)
+    it 'returns an array of labeled issues when all labels matches' do
+      label_b = create(:label, title: 'foo', project: project)
+      label_c = create(:label, title: 'bar', project: project)
+
+      create(:label_link, label: label_b, target: issue)
+      create(:label_link, label: label_c, target: issue)
+
+      get api("#{base_url}/issues", user), labels: "#{label.title},#{label_b.title},#{label_c.title}"
 
       expect(response).to have_http_status(200)
       expect(response).to include_pagination_headers
       expect(json_response).to be_an Array
       expect(json_response.length).to eq(1)
-      expect(json_response.first['labels']).to eq([label.title])
+      expect(json_response.first['labels']).to eq([label_c.title, label_b.title, label.title])
+    end
+
+    it 'returns an empty array if not all labels matches' do
+      get api("#{base_url}/issues?labels=#{label.title},foo", user)
+
+      expect(response).to have_http_status(200)
+      expect(json_response).to be_an Array
+      expect(json_response.length).to eq(0)
     end
 
     it 'returns an empty array if no project issue matches labels' do