fix metrics bug, add published metric

_plugins/gtn/metrics.rb

@@ -50,7 +50,7 @@ def self.histogram(values)
     end
 
     def self.histogram_dates(values)
-      day_bins = [1, 7, 28, 90, 365, 365 * 2, 365 * 3, 365 * 5]
+      day_bins = [1, 7, 28, 90, 365, 365 * 2, 365 * 3, 365 * 5, Float::INFINITY]
       last_bin = 0
       day_bins.map do |bin, _idx|
         count = values.select { |x| last_bin <= x and x < bin }.length
@@ -87,6 +87,8 @@ def self.segment_page_by_key(values, key)
 
     def self.collect_metrics(site)
       tutorials = site.pages.select { |x| x.data['layout'] == 'tutorial_hands_on' }
+      # TODO: materials
+      # materials = site.pages.select { |x| x.data['layout'] == 'tutorial_hands_on' }
       first_commit = Date.parse('2015-06-29')
       today = Date.today
 
@@ -138,6 +140,18 @@ def self.collect_metrics(site)
             .map { |seconds| seconds / 3600.0 / 24.0 }
           )
         },
+        'tutorial_published_age_days' => {
+          type: 'histogram',
+          help: 'How recently was every single Hands-on Tutorial published within the GTN, ' \
+                'grouped by days since first published.',
+          value: histogram_dates(
+            tutorials
+            .map do |page|
+              Time.now - Gtn::PublicationTimes.obtain_time(page['path'])
+            end
+            .map { |seconds| seconds / 3600.0 / 24.0 }
+          )
+        },
         'contributor_join_age_days' => {
           type: 'histogram',
           help: 'When did contributors join? Buckets of their ages by days since joined.',