Converted should_have_and_belong_to_many to use a matcher

lib/shoulda/active_record/macros.rb

@@ -446,12 +446,9 @@ module Shoulda # :nodoc:
         klass = model_class
 
         associations.each do |association|
-          should "should have and belong to many #{association}" do
-            reflection = klass.reflect_on_association(association)
-            assert reflection, "#{klass.name} does not have any relationship to #{association}"
-            assert_equal :has_and_belongs_to_many, reflection.macro
-            table = reflection.options[:join_table]
-            assert ::ActiveRecord::Base.connection.tables.include?(table.to_s), "table #{table} doesn't exist"
+          matcher = have_and_belong_to_many(association)
+          should matcher.description do
+            assert_accepts(matcher, klass.new)
           end
         end
       end

lib/shoulda/active_record/matchers/association_matcher.rb

@@ -24,7 +24,8 @@ module Shoulda # :nodoc:
             macro_correct? && 
             foreign_key_exists? && 
             through_association_valid? && 
-            dependent_correct?
+            dependent_correct? &&
+            join_table_exists?
         end
 
         def failure_message
@@ -108,6 +109,16 @@ module Shoulda # :nodoc:
           end
         end
 
+        def join_table_exists?
+          if @macro != :has_and_belongs_to_many || 
+              ::ActiveRecord::Base.connection.tables.include?(join_table.to_s)
+            true
+          else
+            @missing = "join table #{join_table} doesn't exist"
+            false
+          end
+        end
+
         def class_has_foreign_key?(klass)
           if klass.column_names.include?(foreign_key.to_s)
             true
@@ -121,6 +132,10 @@ module Shoulda # :nodoc:
           @subject.class
         end
 
+        def join_table
+          reflection.options[:join_table]
+        end
+
         def associated_class
           reflection.klass
         end
@@ -149,7 +164,9 @@ module Shoulda # :nodoc:
           case @macro.to_s
           when 'belongs_to' then 'belong to'
           when 'has_many'   then 'have many'
-          when 'has_one'    then 'has one'
+          when 'has_one'    then 'have one'
+          when 'has_and_belongs_to_many' then
+            'have and belong to many'
           end
         end
       end
@@ -166,6 +183,10 @@ module Shoulda # :nodoc:
         AssociationMatcher.new(:has_one, name)
       end
 
+      def have_and_belong_to_many(name)
+        AssociationMatcher.new(:has_and_belongs_to_many, name)
+      end
+
     end
   end
 end

test/other/active_record_matchers_test.rb

@@ -103,7 +103,7 @@ class ActiveRecordMatchersTest < Test::Unit::TestCase # :nodoc:
     end
   end
 
-  context "has_one" do
+  context "have_one" do
     should "accept a valid association without any options" do
       assert_accepts have_one(:friendship), User.new
     end
@@ -129,4 +129,22 @@ class ActiveRecordMatchersTest < Test::Unit::TestCase # :nodoc:
     end
   end
 
+  context "have_and_belong_to_many" do
+    should "accept a valid association" do
+      assert_accepts have_and_belong_to_many(:fleas), Dog.new
+    end
+
+    should "reject a nonexistent association" do
+      assert_rejects have_and_belong_to_many(:parties), User.new
+    end
+
+    should "reject an association with a nonexistent join table" do
+      assert_rejects have_and_belong_to_many(:stores), Product.new
+    end
+
+    should "reject an association of the wrong type" do
+      assert_rejects have_and_belong_to_many(:friends), User.new
+    end
+  end
+
 end