Change `percent` to `rate` in retention metrics API (#16910)

app/javascript/mastodon/components/admin/Retention.js

@@ -88,7 +88,7 @@ export default class Retention extends React.PureComponent {
               </td>
 
               {data[0].data.slice(1).map((retention, i) => {
-                const average = data.reduce((sum, cohort, k) => cohort.data[i + 1] ? sum + (cohort.data[i + 1].percent - sum)/(k + 1) : sum, 0);
+                const average = data.reduce((sum, cohort, k) => cohort.data[i + 1] ? sum + (cohort.data[i + 1].rate - sum)/(k + 1) : sum, 0);
 
                 return (
                   <td key={retention.date}>
@@ -118,8 +118,8 @@ export default class Retention extends React.PureComponent {
 
                 {cohort.data.slice(1).map(retention => (
                   <td key={retention.date}>
-                    <div className={classNames('retention__table__box', `retention__table__box--${roundTo10(retention.percent * 100)}`)}>
-                      <FormattedNumber value={retention.percent} style='percent' />
+                    <div className={classNames('retention__table__box', `retention__table__box--${roundTo10(retention.rate * 100)}`)}>
+                      <FormattedNumber value={retention.rate} style='percent' />
                     </div>
                   </td>
                 ))}

app/lib/admin/metrics/retention.rb

@@ -6,7 +6,7 @@ class Admin::Metrics::Retention
   end
 
   class CohortData < ActiveModelSerializers::Model
-    attributes :date, :percent, :value
+    attributes :date, :rate, :value
   end
 
   def initialize(start_at, end_at, frequency)
@@ -59,7 +59,7 @@ class Admin::Metrics::Retention
 
       current_cohort.data << CohortData.new(
         date: row['retention_period'],
-        percent: rate.to_f,
+        rate: rate.to_f,
         value: value.to_s
       )
     end

app/serializers/rest/admin/cohort_serializer.rb

@@ -4,7 +4,7 @@ class REST::Admin::CohortSerializer < ActiveModel::Serializer
   attributes :period, :frequency
 
   class CohortDataSerializer < ActiveModel::Serializer
-    attributes :date, :percent, :value
+    attributes :date, :rate, :value
 
     def date
       object.date.iso8601