feat: trigger function making sure the committed changes are immutable

schema/deploy/trigger_functions/committed_changes_are_immutable.sql

@@ -0,0 +1,24 @@
+-- Deploy cif:trigger_functions/committed_changes_are_immutable to pg
+
+begin;
+
+create or replace function cif_private.committed_changes_are_immutable()
+returns trigger as $$
+begin
+  if (select triggers_commit from cif.change_status where status=old.change_status) then
+    raise exception 'Committed records cannot be modified';
+  end if;
+
+  return new;
+end;
+$$ language plpgsql;
+
+grant execute on function cif_private.committed_changes_are_immutable to cif_internal, cif_external, cif_admin;
+
+comment on function cif_private.committed_changes_are_immutable()
+  is $$
+  A trigger that raises an exception if changes happen on a record where the change_status triggers a commit.
+  $$;
+
+
+commit;

schema/revert/trigger_functions/committed_changes_are_immutable.sql

@@ -0,0 +1,7 @@
+-- Revert cif:trigger_functions/committed_changes_are_immutable from pg
+
+begin;
+
+drop function cif_private.committed_changes_are_immutable;
+
+commit;

schema/sqitch.plan

@@ -29,6 +29,7 @@ tables/project [tables/operator] 2021-11-04T20:34:23Z Pierre Bastianelli <pierre
 util_functions/camel_to_snake_case 2021-12-11T00:37:54Z Matthieu Foucault <[email protected]> # Add cif_private.camel_to_snake_case
 trigger_functions/commit_form_change [schemas/private util_functions/camel_to_snake_case] 2021-11-08T22:54:27Z Dylan Leard <[email protected]> # Trigger function to apply changes to a table once the change has been committed
 tables/change_status [schemas/main] 2021-11-08T22:46:03Z Pierre Bastianelli <[email protected]> # Table to constrain the status of a form_change row
+trigger_functions/committed_changes_are_immutable 2022-01-06T23:40:27Z Pierre Bastianelli <[email protected]> # Trigger to prevent committed changes from being altered
 trigger_functions/commit_project_revision 2021-12-07T00:37:33Z Pierre Bastianelli <[email protected]> # A trigger function executed when a whole project revision is committed, triggering commit on the individual form_change records
 tables/project_revision 2021-12-07T00:39:51Z Pierre Bastianelli <[email protected]> # A table to track global project revisions - containing multiple changes
 tables/form_change [tables/change_status] 2021-11-04T20:58:49Z Pierre Bastianelli <[email protected]> # Form history table to track changes to records

schema/test/unit/trigger_functions/committed_changes_are_immutable_test.sql

@@ -0,0 +1,41 @@
+begin;
+
+select plan(3);
+
+-- Testing table with a deleted_at column
+
+insert into cif.change_status (status, triggers_commit, active) values ('testcommitted', true, true), ('testpending', false, true);
+
+create table test_table_with_status(
+  test_col text,
+  change_status varchar(1000) references cif.change_status
+);
+
+create trigger trigger_under_test before update on test_table_with_status for each row
+execute procedure cif_private.committed_changes_are_immutable();
+
+insert into test_table_with_status(test_col, change_status) values ('test_active', 'testpending'), ('test_committed', 'testcommitted');
+
+select lives_ok(
+  $$
+    update test_table_with_status set test_col = 'test_changed_active' where test_col = 'test_active'
+  $$,
+  'doesnt throw if the change status isn''t committed'
+);
+
+select is(
+  (select count(*) from test_table_with_status where test_col = 'test_changed_active'),
+  1::bigint,
+  'allows the record to be updated if the change status isn''t committed'
+);
+
+select throws_ok(
+  $$
+    update test_table_with_status set test_col = 'test_changed_committed' where test_col = 'test_committed'
+  $$,
+  'Committed records cannot be modified',
+  'throws if the change_status is committed'
+);
+
+
+rollback;

schema/verify/trigger_functions/committed_changes_are_immutable.sql

@@ -0,0 +1,7 @@
+-- Verify cif:trigger_functions/committed_changes_are_immutable on pg
+
+begin;
+
+select pg_get_functiondef('cif_private.committed_changes_are_immutable()'::regprocedure);
+
+rollback;