Make `/features` API accept percentage as float to enable 0.01%

lib/api/features.rb

@@ -14,7 +14,12 @@ module API
         when '0', 'false'
           false
         else
-          params[:value].to_i
+          # https://github.com/jnunemaker/flipper/blob/master/lib/flipper/typecast.rb#L47
+          if params[:value].to_s.include?('.')
+            params[:value].to_f
+          else
+            params[:value].to_i
+          end
         end
       end
 
@@ -59,7 +64,7 @@ module API
         success Entities::Feature
       end
       params do
-        requires :value, type: String, desc: '`true` or `false` to enable/disable, an integer for percentage of time'
+        requires :value, type: String, desc: '`true` or `false` to enable/disable, a float for percentage of time'
         optional :key, type: String, desc: '`percentage_of_actors` or the default `percentage_of_time`'
         optional :feature_group, type: String, desc: 'A Feature group name'
         optional :user, type: String, desc: 'A GitLab username'

spec/requests/api/features_spec.rb

@@ -256,6 +256,21 @@ RSpec.describe API::Features, stub_feature_flags: false do
         )
       end
 
+      it 'creates a feature with the given percentage of time if passed a float' do
+        post api("/features/#{feature_name}", admin), params: { value: '0.01' }
+
+        expect(response).to have_gitlab_http_status(:created)
+        expect(json_response).to match(
+          'name' => feature_name,
+          'state' => 'conditional',
+          'gates' => [
+            { 'key' => 'boolean', 'value' => false },
+            { 'key' => 'percentage_of_time', 'value' => 0.01 }
+          ],
+          'definition' => known_feature_flag_definition_hash
+        )
+      end
+
       it 'creates a feature with the given percentage of actors if passed an integer' do
         post api("/features/#{feature_name}", admin), params: { value: '50', key: 'percentage_of_actors' }
 
@@ -270,6 +285,21 @@ RSpec.describe API::Features, stub_feature_flags: false do
           'definition' => known_feature_flag_definition_hash
         )
       end
+
+      it 'creates a feature with the given percentage of actors if passed a float' do
+        post api("/features/#{feature_name}", admin), params: { value: '0.01', key: 'percentage_of_actors' }
+
+        expect(response).to have_gitlab_http_status(:created)
+        expect(json_response).to match(
+          'name' => feature_name,
+          'state' => 'conditional',
+          'gates' => [
+            { 'key' => 'boolean', 'value' => false },
+            { 'key' => 'percentage_of_actors', 'value' => 0.01 }
+          ],
+          'definition' => known_feature_flag_definition_hash
+        )
+      end
     end
 
     context 'when the feature exists' do