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ActiveRecord Truncation does not work when using multiple schemas

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
45/100
Issue type
Bug
Clarity
Clearly specified
Activity status
Stale
Tech stack
postgresql, rails, ruby
Domain
databases, testing

Research direction

Start with lib/database_cleaner/active_record/truncation.rb, especially the table-list query at lines 191–196, and reproduce it with the public, earth, and mars schemas described in the issue. Confirm that truncation cleans tenant tables while still excluding schema_migrations, ar_internal_metadata, pg_catalog, and information_schema.

Written by the indexing model from the issue text.

Description

Hello - thanks for putting together database_cleaner! I've been using the gem for a while and I know maintenance takes effort, so appreciate those who contribute to this project.

I'm using the following setup -

  • Rails 5.1.0
  • ActiveRecord 3.0.0
  • Postgres 9.6

Like many multi-tenant applications, my app utilizes postgres schemas which store parrallel, independent copies of my database tables.

So if I have two tenants (earth, mars) and two tables (users, companies) I would have the following tables in my DB -

schema_migrations
ar_internal_metadata
public.users
public.companies
earth.users
earth.companies
mars.users
mars.companies

When using DatabaseCleaner.strategy = :truncation, it looks for a list of tables in my DB to truncate (see here).

When I run that query against my local test database -

SELECT schemaname || '.' || tablename
FROM pg_tables
WHERE
  tablename !~ '_prt_' AND
  tablename <> 'schema_migrations' AND tablename <> 'ar_internal_metadata'
  AND schemaname = ANY (current_schemas(false))
;
                 ?column?
-------------------------------------------
 public.users
 public.companies
(2 rows)

As you can see, it only returns the public schemas, because of the schemaname = criteria. This effectively doesn't wipe my non-public schema tables, causing run-over between tests.

I understand that there are options to use a transaction instead, or even the only: [..] parameter to list all my tables. But it seems like this should work as is without having to use one of those as a workaround (and if my DB is quite large, a whitelist can get messy and inefficient across thousands of tests).

Would it make sense to update the query logic to something like

SELECT schemaname || '.' || tablename
FROM pg_tables
WHERE
  tablename !~ '_prt_' AND
  tablename <> 'schema_migrations' AND tablename <> 'ar_internal_metadata'
  AND schemaname NOT IN ('pg_catalog', 'information_schema')
;

Thanks!

Related to: https://github.com/DatabaseCleaner/database_cleaner/issues/225

Dominant language
Ruby
Stars
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Forks
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