The default value of a text/blob in mysql strict mode should be nil

In non-strict mode it is '', but if someone is in strict mode then we
should honour the strict semantics.

Also, this removes the need for a completely horrible hack in dirty.rb.

Closes #7780

1 files changed, 55 insertions, 17 deletions

diff --git a/activerecord/test/cases/defaults_test.rb b/activerecord/test/cases/defaults_test.rb
index 72f1c99ca0..0df872ff10 100644
--- a/activerecord/test/cases/defaults_test.rb
+++ b/activerecord/test/cases/defaults_test.rb
@@ -51,11 +51,60 @@ if current_adapter?(:MysqlAdapter) or current_adapter?(:Mysql2Adapter)
     # We don't want that to happen, so we disable transactional fixtures here.
     self.use_transactional_fixtures = false
 
-    # MySQL 5 and higher is quirky with not null text/blob columns.
-    # With MySQL Text/blob columns cannot have defaults. If the column is not
-    # null MySQL will report that the column has a null default
-    # but it behaves as though the column had a default of ''
-    def test_mysql_text_not_null_defaults
+    def using_strict(strict)
+      connection = ActiveRecord::Model.remove_connection
+      ActiveRecord::Model.establish_connection connection.merge(strict: strict)
+      yield
+    ensure
+      ActiveRecord::Model.remove_connection
+      ActiveRecord::Model.establish_connection connection
+    end
+
+    # MySQL cannot have defaults on text/blob columns. It reports the
+    # default value as null.
+    #
+    # Despite this, in non-strict mode, MySQL will use an empty string
+    # as the default value of the field, if no other value is
+    # specified.
+    #
+    # Therefore, in non-strict mode, we want column.default to report
+    # an empty string as its default, to be consistent with that.
+    #
+    # In strict mode, column.default should be nil.
+    def test_mysql_text_not_null_defaults_non_strict
+      using_strict(false) do
+        with_text_blob_not_null_table do |klass|
+          assert_equal '', klass.columns_hash['non_null_blob'].default
+          assert_equal '', klass.columns_hash['non_null_text'].default
+
+          assert_nil klass.columns_hash['null_blob'].default
+          assert_nil klass.columns_hash['null_text'].default
+
+          instance = klass.create!
+
+          assert_equal '', instance.non_null_text
+          assert_equal '', instance.non_null_blob
+
+          assert_nil instance.null_text
+          assert_nil instance.null_blob
+        end
+      end
+    end
+
+    def test_mysql_text_not_null_defaults_strict
+      using_strict(true) do
+        with_text_blob_not_null_table do |klass|
+          assert_nil klass.columns_hash['non_null_blob'].default
+          assert_nil klass.columns_hash['non_null_text'].default
+          assert_nil klass.columns_hash['null_blob'].default
+          assert_nil klass.columns_hash['null_text'].default
+
+          assert_raises(ActiveRecord::StatementInvalid) { klass.create }
+        end
+      end
+    end
+
+    def with_text_blob_not_null_table
       klass = Class.new(ActiveRecord::Base)
       klass.table_name = 'test_mysql_text_not_null_defaults'
       klass.connection.create_table klass.table_name do |t|
@@ -64,19 +113,8 @@ if current_adapter?(:MysqlAdapter) or current_adapter?(:Mysql2Adapter)
         t.column :null_text, :text, :null => true
         t.column :null_blob, :blob, :null => true
       end
-      assert_equal '', klass.columns_hash['non_null_blob'].default
-      assert_equal '', klass.columns_hash['non_null_text'].default
-
-      assert_nil klass.columns_hash['null_blob'].default
-      assert_nil klass.columns_hash['null_text'].default
 
-      assert_nothing_raised do
-        instance = klass.create!
-        assert_equal '', instance.non_null_text
-        assert_equal '', instance.non_null_blob
-        assert_nil instance.null_text
-        assert_nil instance.null_blob
-      end
+      yield klass
     ensure
       klass.connection.drop_table(klass.table_name) rescue nil
     end