Upgrading to Rails 7.2: Four Breaking Changes We Hit

Four things broke moving from Rails 7.1 to 7.2.

show_exceptions no longer takes true/false

Setting it to false used to mean exceptions raise instead of rendering an error page, which specs relied on. That behavior now needs :none.

   # Raise exceptions instead of rendering exception templates.
-  config.action_dispatch.show_exceptions = false
+  config.action_dispatch.show_exceptions = :none

SQL generated for array containment changed

-    if link = where('course_ids @> \'{?}\'', course.id).first
+    if link = where('course_ids @> ARRAY[?]::bigint[]', course.id).first

lock_thread= is gone from the connection pool

NoMethodError: undefined method `lock_thread=' for an instance of ActiveRecord::ConnectionAdapters::ConnectionPool

-    ActiveRecord::Base.connection.pool.lock_thread = false
+    # ActiveRecord::Base.connection.pool.lock_thread = false

assert_enqueued_email_with takes params, not args

-    assert_enqueued_email_with UserMailer, :invitation, args: { invitation: invitation }
+    assert_enqueued_email_with UserMailer, :invitation, params: { invitation: invitation }

None of these needed a redesign, just a grep for each pattern across the codebase before merging the upgrade.