Fix for the Rails test schema including decimal greater than 38 precision (#1181)

Author: aidanharan

test/cases/helper_sqlserver.rb

@@ -7,6 +7,7 @@
 require "support/core_ext/query_cache"
 require "support/minitest_sqlserver"
 require "support/test_in_memory_oltp"
+require "support/table_definition_sqlserver"
 require "cases/helper"
 require "support/load_schema_sqlserver"
 require "support/coerceable_test_sqlserver"

test/support/table_definition_sqlserver.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  module ConnectionAdapters
+    module SQLServer
+      class TableDefinition < ::ActiveRecord::ConnectionAdapters::TableDefinition
+        # SQL Server supports precision of 38 for decimal columns. In Rails the test schema includes a column
+        # with a precision of 55. This is a problem for SQL Server 2008. This method will override the default
+        # decimal method to limit the precision to 38 for the :atoms_in_universe column.
+        # See https://github.com/rails/rails/pull/51826/files#diff-2a57b61bbf9ee2c23938fc571d403799f68b4b530d65e2cde219a429bbf10af5L876
+        def decimal(*names, **options)
+          throw "This 'decimal' method should only be used in a test environment." unless defined?(ActiveSupport::TestCase)
+
+          names.each do |name|
+            options_for_name = options.dup
+            options_for_name[:precision] = 38 if name == :atoms_in_universe && options_for_name[:precision].to_i == 55
+
+            column(name, :decimal, **options_for_name)
+          end
+        end
+      end
+    end
+  end
+end