Fix almost all Ruby warnings during spec suite

lib/arel/algebra/extensions/class.rb

@@ -2,7 +2,7 @@ module Arel
   module ClassExtensions
     def attributes(*attrs)
       @attributes = attrs
-      attr_reader *attrs
+      attr_reader(*attrs)
     end
 
     def deriving(*methods)

lib/arel/session.rb

@@ -5,16 +5,22 @@ module Arel
       alias_method :manufacture, :new
 
       def start
-        if @started
+        if defined?(@started) && @started
           yield
         else
           begin
             @started = true
             @instance = manufacture
-            metaclass.send :alias_method, :new, :instance
+            metaclass.class_eval do
+              undef :new
+              alias_method :new, :instance
+            end
             yield
           ensure
-            metaclass.send :alias_method, :new, :manufacture
+            metaclass.class_eval do
+              undef :new
+              alias_method :new, :manufacture
+            end
             @started = false
           end
         end

spec/arel/algebra/unit/predicates/equality_spec.rb

@@ -11,7 +11,7 @@ module Arel
 
     describe '==' do
       it "obtains if attribute1 and attribute2 are identical" do
-        Equality.new(@attribute1, @attribute2).should == Equality.new(@attribute1, @attribute2)
+        check Equality.new(@attribute1, @attribute2).should == Equality.new(@attribute1, @attribute2)
         Equality.new(@attribute1, @attribute2).should_not == Equality.new(@attribute1, @attribute1)
       end
 

spec/arel/algebra/unit/primitives/attribute_spec.rb

@@ -73,10 +73,8 @@ module Arel
 
         describe 'when dividing two matching attributes' do
           it 'returns a the highest score for the most similar attributes' do
-            (@aliased_relation[:id] / @relation[:id]) \
-              .should == (@aliased_relation[:id] / @relation[:id])
-            (@aliased_relation[:id] / @relation[:id]) \
-              .should < (@aliased_relation[:id] / @aliased_relation[:id])
+            check((@aliased_relation[:id] / @relation[:id]).should == (@aliased_relation[:id] / @relation[:id]))
+            (@aliased_relation[:id] / @relation[:id]).should < (@aliased_relation[:id] / @aliased_relation[:id])
           end
         end
       end

spec/arel/algebra/unit/relations/alias_spec.rb

@@ -8,7 +8,7 @@ module Arel
 
     describe '==' do
       it "obtains if the objects are the same" do
-        Alias.new(@relation).should_not == Alias.new(@relation)
+        check Alias.new(@relation).should_not == Alias.new(@relation)
         (aliaz = Alias.new(@relation)).should == aliaz
       end
     end

spec/arel/algebra/unit/relations/relation_spec.rb

@@ -17,8 +17,8 @@ module Arel
 
       describe 'when given a', Symbol, String do
         it "returns the attribute with the same name, if it exists" do
-          @relation[:id].should == @attribute1
-          @relation['id'].should == @attribute1
+          check @relation[:id].should == @attribute1
+          check @relation['id'].should == @attribute1
           @relation[:does_not_exist].should be_nil
         end
       end
@@ -180,7 +180,7 @@ module Arel
 
     describe Relation::Enumerable do
       it "implements enumerable" do
-        @relation.collect.should == @relation.session.read(@relation).collect
+        check @relation.collect.should == @relation.session.read(@relation).collect
         @relation.first.should   == @relation.session.read(@relation).first
       end
     end

spec/arel/algebra/unit/relations/table_spec.rb

@@ -9,7 +9,7 @@ module Arel
     describe '[]' do
       describe 'when given a', Symbol do
         it "manufactures an attribute if the symbol names an attribute within the relation" do
-          @relation[:id].should == Attribute.new(@relation, :id)
+          check @relation[:id].should == Attribute.new(@relation, :id)
           @relation[:does_not_exist].should be_nil
         end
       end

spec/arel/engines/sql/unit/predicates/binary_spec.rb

@@ -2,15 +2,16 @@ require 'spec_helper'
 
 module Arel
   describe Binary do
+    class ConcreteBinary < Binary
+      def predicate_sql
+        "<=>"
+      end
+    end
+
     before do
       @relation = Table.new(:users)
       @attribute1 = @relation[:id]
       @attribute2 = @relation[:name]
-      class ConcreteBinary < Binary
-        def predicate_sql
-          "<=>"
-        end
-      end
     end
 
     describe "with compound predicates" do

spec/doubles/hash.rb

@@ -3,18 +3,22 @@ class Hash
     to_a.sort { |(key1, value1), (key2, value2)| key1.hash <=> key2.hash }
   end
 
+  undef :keys
   def keys
     ordered_array.collect(&:first)
   end
 
+  undef :values
   def values
     ordered_array.collect { |_, v| v }
   end
 
+  undef :each
   def each(&block)
     ordered_array.each(&block)
   end
 
+  undef :shift
   def shift
     returning to_a.first do |k, v|
       delete(k)

spec/spec_helper.rb

@@ -37,9 +37,17 @@ module AdapterGuards
   end
 end
 
+module Check
+  # This is used to eliminate Ruby warnings on some RSpec assertion lines
+  # See: https://rspec.lighthouseapp.com/projects/5645/tickets/504
+  def check(*args)
+  end
+end
+
 Spec::Runner.configure do |config|
   config.include BeLikeMatcher, HashTheSameAsMatcher, DisambiguateAttributesMatcher
   config.include AdapterGuards
+  config.include Check
   config.mock_with :rr
   config.before do
     Arel::Table.engine = Arel::Sql::Engine.new(ActiveRecord::Base)