Avoid need to be db superuser to run tests

Add a patch from louisecrow (https://github.com/mysociety/fixmytransport/blob/master/lib/patches/fixtures_constraint_disabling.rb)
that makes it possible to run the tests without being a database superuser.

2 files changed, 23 insertions, 0 deletions

diff --git a/config/environments/test.rb b/config/environments/test.rb
index 8d6041ad9..be28c3df6 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -1,5 +1,7 @@
 # Settings specified here will take precedence over those in config/environment.rb
 
+require 'lib/patches/fixtures_constraint_disabling'
+
 # The test environment is used exclusively to run your application's
 # test suite.  You never need to work with it otherwise.  Remember that
 # your test database is "scratch space" for the test suite and is wiped
diff --git a/lib/patches/fixtures_constraint_disabling.rb b/lib/patches/fixtures_constraint_disabling.rb
new file mode 100644
index 000000000..7d97e81f7
--- /dev/null
+++ b/lib/patches/fixtures_constraint_disabling.rb
@@ -0,0 +1,21 @@
+# An alternative way of disabling foreign keys in fixture loading in Postgres and
+# does not require superuser permissions
+# http://kopongo.com/2008/7/25/postgres-ri_constrainttrigger-error
+require 'active_record/connection_adapters/postgresql_adapter'
+module ActiveRecord
+  module ConnectionAdapters
+    class PostgreSQLAdapter < AbstractAdapter
+      def disable_referential_integrity(&block)
+         transaction {
+           begin
+             execute "SET CONSTRAINTS ALL DEFERRED"
+             yield
+           ensure
+             execute "SET CONSTRAINTS ALL IMMEDIATE"
+           end
+         }
+      end
+    end
+  end
+end
+