[Fix rubocop#1770] Add utc/localtime support to Rails/TimeZone

CHANGELOG.md

@@ -9,6 +9,7 @@
 * [#1773](https://github.com/bbatsov/rubocop/pull/1773): Fix typo ('strptime' -> 'strftime') in `Rails/TimeZone`. ([@palkan][])
 * [#1777](https://github.com/bbatsov/rubocop/pull/1777): Fix offense message from Rails/TimeZone. ([@mzp][])
 * Fix handling of `while` and `until` with assignment in `IndentationWidth`. ([@lumeet][])
+* [#1767](https://github.com/bbatsov/rubocop/pull/1767): Do not register offenses on Time.utc and Time.localtime(offset) by `Rails/TimeZone`. ([@palkan][])
 
 ## 0.30.0 (06/04/2015)
 

lib/rubocop/cop/rails/time_zone.rb

@@ -31,6 +31,8 @@ class TimeZone < Cop
 
         MSG = 'Do not use `%s` without zone. Use `%s` instead.'
 
+        MSG_LOCALTIME = 'Do not use `Time.localtime` without offset or zone.'
+
         TIMECLASS = [:Time, :DateTime]
 
         DANGER_METHODS = [:now, :local, :new, :strftime, :parse, :at]
@@ -50,6 +52,8 @@ def check_time_node(klass, node)
           return if (chain & DANGER_METHODS).empty? ||
                     !(chain & good_methods).empty?
 
+          return check_localtime(node) if chain.include?(:localtime)
+
           method_name = (chain & DANGER_METHODS).join('.')
           safe_method_name = safe_method(method_name, node)
 
@@ -96,8 +100,19 @@ def safe_method(method_name, node)
           end
         end
 
+        def check_localtime(node)
+          p = node
+          while !p.nil? && p.send_type?
+            break if extract_method(p) == :localtime
+            p = p.parent
+          end
+          _receiver, _method, args = *p
+
+          add_offense(node, :selector, MSG_LOCALTIME) if args.nil?
+        end
+
         def good_methods
-          style == :always ? [:zone] : [:zone, :in_time_zone]
+          style == :always ? [:zone, :utc] : [:zone, :utc, :in_time_zone]
         end
       end
     end

spec/rubocop/cop/rails/time_zone_spec.rb

@@ -30,6 +30,11 @@
         expect(cop.offenses.size).to eq(1)
         expect(cop.offenses.first.message).to include('Time.zone.local')
       end
+
+      it "accepts #{klass}.now.utc" do
+        inspect_source(cop, "#{klass}.now.utc")
+        expect(cop.offenses).to be_empty
+      end
     end
 
     it 'registers an offense for Time.parse' do
@@ -71,6 +76,11 @@
       expect(cop.offenses.size).to eq(1)
     end
 
+    it 'registers an offense for Time.parse.localtime' do
+      inspect_source(cop, "Time.parse('12:00').localtime")
+      expect(cop.offenses.size).to eq(1)
+    end
+
     it 'registers an offense for Time.at.in_time_zone' do
       inspect_source(cop, 'Time.at(ts).in_time_zone')
       expect(cop.offenses.size).to eq(1)
@@ -113,6 +123,16 @@
       )
       expect(cop.offenses).to be_empty
     end
+
+    it 'accepts Time.parse.localtime(offset)' do
+      inspect_source(cop, "Time.parse('12:00').localtime('+03:00')")
+      expect(cop.offenses).to be_empty
+    end
+
+    it 'accepts Time.zone.parse.localtime' do
+      inspect_source(cop, "Time.zone.parse('12:00').localtime")
+      expect(cop.offenses).to be_empty
+    end
   end
 
   context 'when EnforcedStyle is "ignore_acceptable"' do