Allow to customize keys for timezone_data helper

Allow to pick different sets of attributes for timezone_data helper

app/helpers/time_zone_helper.rb

 # frozen_string_literal: true
 
 module TimeZoneHelper
-  def timezone_data
+  TIME_ZONE_FORMAT_ATTRS = {
+    short: %i[identifier name offset],
+    full: %i[identifier name abbr offset formatted_offset]
+  }.freeze
+  private_constant :TIME_ZONE_FORMAT_ATTRS
+
+  # format:
+  #   * :full - all available fields
+  #   * :short (default)
+  #
+  # Example:
+  #   timezone_data # :short by default
+  #   timezone_data(format: :full)
+  #
+  def timezone_data(format: :short)
+    attrs = TIME_ZONE_FORMAT_ATTRS.fetch(format) do
+      valid_formats = TIME_ZONE_FORMAT_ATTRS.keys.map { |k| ":#{k}"}.join(", ")
+      raise ArgumentError.new("Invalid format :#{format}. Valid formats are #{valid_formats}.")
+    end
+
     ActiveSupport::TimeZone.all.map do |timezone|
       {
         identifier: timezone.tzinfo.identifier,
@@ -9,7 +28,7 @@ module TimeZoneHelper
         abbr: timezone.tzinfo.strftime('%Z'),
         offset: timezone.now.utc_offset,
         formatted_offset: timezone.now.formatted_offset
-      }
+      }.slice(*attrs)
     end
   end
 end

ee/app/helpers/incident_management/oncall_schedule_helper.rb

@@ -6,7 +6,7 @@ module IncidentManagement
       {
         'project-path' => project.full_path,
         'empty-oncall-schedules-svg-path' => image_path('illustrations/empty-state/empty-on-call.svg'),
-        'timezones' => timezone_data.to_json
+        'timezones' => timezone_data(format: :full).to_json
       }
     end
   end

ee/spec/helpers/incident_management/oncall_schedule_helper_spec.rb

@@ -12,7 +12,7 @@ RSpec.describe IncidentManagement::OncallScheduleHelper do
       is_expected.to eq(
         'project-path' => project.full_path,
         'empty-oncall-schedules-svg-path' => helper.image_path('illustrations/empty-state/empty-on-call.svg'),
-        'timezones' => helper.timezone_data.to_json
+        'timezones' => helper.timezone_data(format: :full).to_json
       )
     end
   end

spec/helpers/time_zone_helper_spec.rb

@@ -4,8 +4,35 @@ require 'spec_helper'
 
 RSpec.describe TimeZoneHelper, :aggregate_failures do
   describe '#timezone_data' do
+    context 'with short format' do
       subject(:timezone_data) { helper.timezone_data }
 
+      it 'matches schema' do
+        expect(timezone_data).not_to be_empty
+
+        timezone_data.each_with_index do |timezone_hash, i|
+          expect(timezone_hash.keys).to contain_exactly(
+            :identifier,
+            :name,
+            :offset
+          ), "Failed at index #{i}"
+        end
+      end
+
+      it 'formats for display' do
+        tz = ActiveSupport::TimeZone.all[0]
+
+        expect(timezone_data[0]).to eq(
+          identifier: tz.tzinfo.identifier,
+          name: tz.name,
+          offset: tz.now.utc_offset
+        )
+      end
+    end
+
+    context 'with full format' do
+      subject(:timezone_data) { helper.timezone_data(format: :full) }
+
       it 'matches schema' do
         expect(timezone_data).not_to be_empty
 
@@ -32,4 +59,13 @@ RSpec.describe TimeZoneHelper, :aggregate_failures do
         )
       end
     end
+
+    context 'with unknown format' do
+      subject(:timezone_data) { helper.timezone_data(format: :unknown) }
+
+      it 'raises an exception' do
+        expect { timezone_data }.to raise_error ArgumentError, 'Invalid format :unknown. Valid formats are :short, :full.'
+      end
+    end
+  end
 end