Add expression support on the schema default

Example:

    create_table :posts do |t|
      t.datetime :published_at, default: -> { 'NOW()' }
    end

1 files changed, 15 insertions, 0 deletions

diff --git a/activerecord/test/cases/defaults_test.rb b/activerecord/test/cases/defaults_test.rb
index fb2d3bd497..ab5641d2dd 100644
--- a/activerecord/test/cases/defaults_test.rb
+++ b/activerecord/test/cases/defaults_test.rb
@@ -1,4 +1,5 @@
 require "cases/helper"
+require 'support/schema_dumping_helper'
 require 'models/default'
 require 'models/entrant'
 
@@ -80,6 +81,20 @@ class DefaultStringsTest < ActiveRecord::TestCase
   end
 end
 
+if current_adapter?(:PostgreSQLAdapter)
+  class PostgresqlDefaultExpressionTest < ActiveRecord::TestCase
+    include SchemaDumpingHelper
+
+    test "schema dump includes default expression" do
+      output = dump_table_schema("defaults")
+      assert_match %r/t\.date\s+"modified_date",\s+default: -> { "\('now'::text\)::date" }/, output
+      assert_match %r/t\.date\s+"modified_date_function",\s+default: -> { "now\(\)" }/, output
+      assert_match %r/t\.datetime\s+"modified_time",\s+default: -> { "now\(\)" }/, output
+      assert_match %r/t\.datetime\s+"modified_time_function",\s+default: -> { "now\(\)" }/, output
+    end
+  end
+end
+
 if current_adapter?(:Mysql2Adapter)
   class DefaultsTestWithoutTransactionalFixtures < ActiveRecord::TestCase
     # ActiveRecord::Base#create! (and #save and other related methods) will