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

CHANGELOG.md

@@ -13,6 +13,7 @@
 * Fix handling of `while` and `until` with assignment in `IndentationWidth`. ([@lumeet][])
 * [#1793](https://github.com/bbatsov/rubocop/pull/1793): Fix bug in `TrailingComma` that caused `,` in comment to count as a trailing comma. ([@jonas054][])
 * [#1765](https://github.com/bbatsov/rubocop/pull/1765): Update 1.9 hash to stop triggering when the symbol is not valid in the 1.9 hash syntax. ([@crimsonknave][])
+* [#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/date.rb

@@ -81,10 +81,9 @@ def check_date_node(node)
 
         def extract_method_chain(node)
           chain = []
-          p = node
-          while !p.nil? && p.send_type?
-            chain << extract_method(p)
-            p = p.parent
+          while !node.nil? && node.send_type?
+            chain << extract_method(node)
+            node = node.parent
           end
           chain
         end

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)
 
@@ -62,10 +66,9 @@ def check_time_node(klass, node)
 
         def extract_method_chain(node)
           chain = []
-          p = node
-          while !p.nil? && p.send_type?
-            chain << extract_method(p)
-            p = p.parent
+          while !node.nil? && node.send_type?
+            chain << extract_method(node)
+            node = node.parent
           end
           chain
         end
@@ -96,8 +99,19 @@ def safe_method(method_name, node)
           end
         end
 
+        def check_localtime(node)
+          selector_node = node
+          while !node.nil? && node.send_type?
+            break if extract_method(node) == :localtime
+            node = node.parent
+          end
+          _receiver, _method, args = *node
+
+          add_offense(selector_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