Introduce Gitlab::Utils.now so that it's easier to stub

app/models/ci/pipeline.rb

@@ -48,11 +48,11 @@ module Ci
       end
 
       before_transition [:created, :pending] => :running do |pipeline|
-        pipeline.started_at = Time.now
+        pipeline.started_at = Gitlab::Utils.now
       end
 
       before_transition any => [:success, :failed, :canceled] do |pipeline|
-        pipeline.finished_at = Time.now
+        pipeline.finished_at = Gitlab::Utils.now
       end
 
       before_transition do |pipeline|

app/models/concerns/statuseable.rb

@@ -87,7 +87,7 @@ module Statuseable
     if started_at && finished_at
       finished_at - started_at
     elsif started_at
-      Time.now - started_at
+      Gitlab::Utils.now - started_at
     end
   end
 end

lib/gitlab/utils.rb

@@ -7,11 +7,16 @@ module Gitlab
     # @param  cmd [Array<String>]
     # @return [Boolean]
     def system_silent(cmd)
-      Popen::popen(cmd).last.zero?
+      Popen.popen(cmd).last.zero?
     end
 
     def force_utf8(str)
       str.force_encoding(Encoding::UTF_8)
     end
+
+    # The same as Time.now but using this would make it easier to test
+    def now
+      Time.now
+    end
   end
 end

spec/models/ci/pipeline_spec.rb

@@ -129,12 +129,15 @@ describe Ci::Pipeline, models: true do
 
     describe '#duration' do
       before do
-        build.skip
-        build2.skip
+        allow(Gitlab::Utils).to receive(:now).
+          and_return(current - 120, current)
+
+        pipeline.run
+        pipeline.succeed
       end
 
       it 'matches sum of builds duration' do
-        expect(pipeline.reload.duration).to eq(build.duration + build2.duration)
+        expect(pipeline.reload.duration).to eq(120)
       end
     end