time_truncate: simplify conversion code and tests

lib/airbrake-ruby/time_truncate.rb

@@ -6,11 +6,10 @@ module Airbrake
   module TimeTruncate
     # Truncate +time+ to floor minute and turn it into an RFC3339 timestamp.
     #
-    # @param [Time] time
+    # @param [Time, Integer, Float] time
     # @return [String]
     def self.utc_truncate_minutes(time)
-      # time does not have getutc method instead of Time on Rails 7.0.0
-      tm = time.respond_to?(:getutc) ? time.getutc : Time.at(time).getutc
+      tm = Time.at(time).getutc
 
       Time.utc(tm.year, tm.month, tm.day, tm.hour, tm.min).to_datetime.rfc3339
     end

spec/time_truncate_spec.rb

@@ -1,21 +1,30 @@
 RSpec.describe Airbrake::TimeTruncate do
+  time = Time.new(2018, 1, 1, 0, 0, 20, 0)
+  time_with_zone = Time.new(2018, 1, 1, 0, 0, 20, '-05:00')
+
   describe "#utc_truncate_minutes" do
-    it "truncates time to the floor minute and returns an RFC3339 timestamp" do
-      time = Time.new(2018, 1, 1, 0, 0, 20, 0)
-      expect(described_class.utc_truncate_minutes(time))
-        .to eq('2018-01-01T00:00:00+00:00')
+    shared_examples 'time conversion' do |t|
+      it "truncates the time to the floor minute and returns an RFC3339 timestamp" do
+        expect(described_class.utc_truncate_minutes(t))
+          .to eq('2018-01-01T00:00:00+00:00')
+      end
+
+      it "converts time with zone to UTC" do
+        expect(described_class.utc_truncate_minutes(time_with_zone))
+          .to eq('2018-01-01T05:00:00+00:00')
+      end
+    end
+
+    context "when the time argument is a Time object" do
+      include_examples 'time conversion', time
     end
 
-    it "converts time with zone to UTC" do
-      time = Time.new(2018, 1, 1, 0, 0, 20, '-05:00')
-      expect(described_class.utc_truncate_minutes(time))
-        .to eq('2018-01-01T05:00:00+00:00')
+    context "when the time argument is a Float" do
+      include_examples 'time conversion', time.to_f
     end
 
-    it "converts it well even if the argument is an instance of Float" do
-      time = Time.new(2018, 1, 1, 0, 0, 20, '-05:00').to_f
-      expect(described_class.utc_truncate_minutes(time))
-        .to eq('2018-01-01T05:00:00+00:00')
+    context "when the time argument is an Integer" do
+      include_examples 'time conversion', time.to_i
     end
   end
 end