bug fixes: don't dump :case_sensitive => false for index with an expr…

…ession that includes 'lower(name)', and properly dump multi-column case_insensitive indexes.

Closes SchemaPlus#84

lib/schema_plus/active_record/connection_adapters/postgresql_adapter.rb

@@ -143,10 +143,16 @@ def indexes(table_name, name = nil) #:nodoc:
             SQL
 
             column_names = columns.values_at(*index_keys).compact
-            # extract column name from the expression, for a
-            # case-insensitive 
-            if md = expression.try(:match, /^lower\(\(?([^)]+)\)?(::text)?\)$/i)
-              column_names << md[1]
+            case_sensitive = true
+
+            # extract column names from the expression, for a
+            # case-insensitive index
+            if expression
+              rexp_lower = %r{\blower\(\(?([^)]+)(\)::text)?\)}
+              if expression.match /^(#{rexp_lower}(, )?)+$/
+                column_names = expression.scan(rexp_lower).map(&:first)
+                case_sensitive = false
+              end
             end
 
             # add info on sort order for columns (only desc order is explicitly specified, asc is the default)
@@ -158,7 +164,7 @@ def indexes(table_name, name = nil) #:nodoc:
                                                                     :unique => unique,
                                                                     :orders => orders,
                                                                     :conditions => conditions,
-                                                                    :case_sensitive => !(expression =~ /lower/i),
+                                                                    :case_sensitive => case_sensitive,
                                                                     :kind => kind.downcase == "btree" ? nil : kind,
                                                                     :expression => expression)
           end

spec/schema_dumper_spec.rb

@@ -163,8 +163,8 @@ class ::Comment < ActiveRecord::Base ; end
   if SchemaPlusHelpers.postgresql?
 
     it "should define case insensitive index" do
-      with_index Post, :name => "posts_user_body_index", :expression => "USING btree (LOWER(body))" do
-        dump_posts.should match(to_regexp(%q{t.index ["body"], :name => "posts_user_body_index", :case_sensitive => false}))
+      with_index Post, [:body, :string_no_default], :case_sensitive => false do
+        dump_posts.should match(to_regexp(%q{t.index ["body", "string_no_default"], :name => "index_posts_on_body_and_string_no_default", :case_sensitive => false}))
       end
     end
 
@@ -180,6 +180,13 @@ class ::Comment < ActiveRecord::Base ; end
       end
     end
 
+    it "should not define :case_sensitive => false with non-trivial expression" do
+      with_index Post, :name => "posts_user_body_index", :expression => "BTRIM(LOWER(body))" do
+        dump_posts.should match(%r{#{to_regexp(%q{t.index :name => "posts_user_body_index", :expression => "btrim(lower(body))"})}$})
+      end
+    end
+
+
     it "should define kind" do
       with_index Post, :name => "posts_body_index", :expression => "USING hash (body)" do
         dump_posts.should match(to_regexp(%q{t.index ["body"], :name => "posts_body_index", :kind => "hash"}))
@@ -277,7 +284,7 @@ def with_index(model, columns, options = {})
   def determine_index_name(model, columns, options)
     name = columns[:name] if columns.is_a?(Hash)
     name ||= options[:name]
-    name ||= model.indexes.detect { |index| index.table == model.table_name.to_s && index.columns == Array(columns).collect(&:to_s) }.name
+    name ||= model.indexes.detect { |index| index.table == model.table_name.to_s && index.columns.sort == Array(columns).collect(&:to_s).sort }.name
     name
   end