Show the records in Relation#inspect

The reason for removing the previous implementation of `#inspect` was
that it hid from you that you were dealing with a `Relation` rather than
an `Array`.

But it is still useful to be able to see the records, particularly if you're
writing something like the following in tests:

    assert_equal [foo], Post.where(:bar)

If the assertion fails, you want to see what records were actually
loaded.

So this implementation makes it clear that you've got a `Relation`, but
also shows your records.

1 files changed, 4 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index e268d451e0..7725331694 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -514,6 +514,10 @@ module ActiveRecord
       @values.dup
     end
 
+    def inspect
+      "#<#{self.class.name} #{to_a.inspect}>"
+    end
+
     private
 
     def references_eager_loaded_tables?