Filter custom fields by field type

Add ability to filter the `customFields` GraphQL field by `fieldType`.
Changelog: added
EE: true

doc/api/graphql/reference/_index.md

@@ -26737,6 +26737,7 @@ four standard [pagination arguments](#pagination-arguments):
 | Name | Type | Description |
 | ---- | ---- | ----------- |
 | <a id="groupcustomfieldsactive"></a>`active` | [`Boolean`](#boolean) | Filter for active fields. If `false`, excludes active fields. If `true`, returns only active fields. |
+| <a id="groupcustomfieldsfieldtype"></a>`fieldType` | [`CustomFieldType`](#customfieldtype) | Filter for selected field type. |
 | <a id="groupcustomfieldssearch"></a>`search` | [`String`](#string) | Search query for custom field name. |
 | <a id="groupcustomfieldsworkitemtypeids"></a>`workItemTypeIds` | [`[WorkItemsTypeID!]`](#workitemstypeid) | Filter custom fields associated to the given work item types. If empty, returns custom fields not associated to any work item type. |

ee/app/finders/issuables/custom_fields_finder.rb

@@ -15,7 +15,7 @@ def self.active_fields_for_work_item(work_item)
     end
 
     def initialize(
-      current_user, group:, active: nil, search: nil, work_item_type_ids: nil,
+      current_user, group:, active: nil, field_type: nil, search: nil, work_item_type_ids: nil,
       skip_permissions_check: false
     )
       raise ArgumentError, 'group argument is missing' if group.nil?
@@ -23,6 +23,7 @@ def initialize(
       @current_user = current_user
       @group = group
       @active = active
+      @field_type = field_type
       @search = search
       @work_item_type_ids = work_item_type_ids
       @skip_permissions_check = skip_permissions_check
@@ -38,6 +39,7 @@ def execute
       items = Issuables::CustomField.of_namespace(@group)
       items = by_status(items)
       items = by_search(items)
+      items = by_field_type(items)
       items = by_work_item_type_ids(items)
       items.ordered_by_status_and_name
     end
@@ -65,5 +67,11 @@ def by_work_item_type_ids(items)
 
       items.with_work_item_types(@work_item_type_ids)
     end
+
+    def by_field_type(items)
+      return items if @field_type.nil?
+
+      items.of_field_type(@field_type)
+    end
   end
 end

ee/app/graphql/resolvers/issuables/custom_fields_resolver.rb

@@ -12,6 +12,10 @@ class CustomFieldsResolver < BaseResolver
         description: 'Filter for active fields. If `false`, excludes active fields. ' \
           'If `true`, returns only active fields.'
 
+      argument :field_type, ::Types::Issuables::CustomFieldTypeEnum,
+        required: false,
+        description: 'Filter for selected field type.'
+
       argument :search, GraphQL::Types::String,
         required: false,
         description: 'Search query for custom field name.'
@@ -22,13 +26,14 @@ class CustomFieldsResolver < BaseResolver
           'If empty, returns custom fields not associated to any work item type.',
         prepare: ->(global_ids, _ctx) { global_ids.map(&:model_id) }
 
-      def resolve_with_lookahead(active: nil, search: nil, work_item_type_ids: nil)
+      def resolve_with_lookahead(active: nil, field_type: nil, search: nil, work_item_type_ids: nil)
         work_item_type_ids = work_item_type_ids_from(work_item_type_ids) unless work_item_type_ids.nil?
 
         custom_fields = ::Issuables::CustomFieldsFinder.new(
           current_user,
           group: object,
           active: active,
+          field_type: field_type,
           search: search,
           work_item_type_ids: work_item_type_ids
         ).execute

ee/app/models/issuables/custom_field.rb

@@ -40,6 +40,7 @@ class CustomField < ApplicationRecord
     scope :active, -> { where(archived_at: nil) }
     scope :archived, -> { where.not(archived_at: nil) }
     scope :ordered_by_status_and_name, -> { order(Arel.sql('archived_at IS NULL').desc, name: :asc) }
+    scope :of_field_type, ->(field_type) { where(field_type: field_type) }
 
     class << self
       def without_any_work_item_types

ee/spec/factories/issuables/custom_fields.rb

@@ -9,5 +9,9 @@
     trait :archived do
       archived_at { Time.current }
     end
+
+    trait :number do
+      field_type { :number }
+    end
   end
 end

ee/spec/finders/issuables/custom_fields_finder_spec.rb

@@ -102,6 +102,27 @@
     end
   end
 
+  context "when filtering by field type" do
+    let_it_be(:custom_field_number) { create(:custom_field, :number, namespace: group, name: 'number field') }
+
+    context "when field type is nil" do
+      let(:params) { {} }
+
+      it 'returns all custom fields for the group' do
+        expect(custom_fields).to contain_exactly(custom_field_1, custom_field_2, custom_field_archived,
+          custom_field_number)
+      end
+    end
+
+    context "when field is has a value" do
+      let(:params) { { field_type: "number" } }
+
+      it 'returns custom fields of type number' do
+        expect(custom_fields).to contain_exactly(custom_field_number)
+      end
+    end
+  end
+
   context 'when group is nil' do
     let(:group) { nil }
 

ee/spec/models/issuables/custom_field_spec.rb

@@ -316,6 +316,14 @@
       end
     end
 
+    describe ".of_field_type" do
+      let_it_be(:custom_field_number) { create(:custom_field, :number, namespace: group) }
+
+      it "returns custom field of a given field type" do
+        expect(described_class.of_field_type("number")).to contain_exactly(custom_field_number)
+      end
+    end
+
     describe 'work item type scopes' do
       let_it_be(:issue_type) { create(:work_item_type, :issue) }
       let_it_be(:task_type) { create(:work_item_type, :task) }

ee/spec/requests/api/graphql/issuables/custom_fields_spec.rb

@@ -33,10 +33,10 @@
 
   let(:query) do
     <<~QUERY
-    query($active: Boolean, $search: String, $workItemTypeIds: [WorkItemsTypeID!]) {
+    query($active: Boolean, $fieldType: CustomFieldType, $search: String, $workItemTypeIds: [WorkItemsTypeID!]) {
       group(fullPath: "#{group.full_path}") {
         id
-        customFields(active: $active, search: $search, workItemTypeIds: $workItemTypeIds) {
+        customFields(active: $active, fieldType: $fieldType, search: $search, workItemTypeIds: $workItemTypeIds) {
           nodes {
             id
             name
@@ -111,6 +111,17 @@
     end
   end
 
+  context "when filtering by field type" do
+    it 'returns fields of the given type' do
+      post_graphql(query, current_user: guest, variables: { fieldType: 'TEXT' })
+
+      expect(response).to have_gitlab_http_status(:ok)
+      expect(graphql_data_at(:group, :customFields, :nodes)).to match([
+        custom_field_attributes(text_field)
+      ])
+    end
+  end
+
   context 'when searching by name' do
     it 'returns matching fields' do
       post_graphql(query, current_user: guest, variables: { search: 'field' })