ENG-1426 Bug in permission functions

[maparent]

https://linear.app/discourse-graphs/issue/ENG-1426/bug-in-permission-functions

Pointed out by Devin in the group-test branch: there was still an issue with using the obsolete editor field of the SpaceAccess structure in that code.
Surprisingly the bug did not make the function fail, probably because the value is rarely set.
Corrected, and generalized the use of permissions as an input parameter to create_account_in_space.
Also, make sure that one cannot give permissions higher than one's own this way;
but also do not lower the permissions if no change was requested.

https://www.loom.com/share/a7089d0681c84d659c1220a70dbb0c0e

---

[linear]

ENG-1426 Bug in permission functions

[supabase]

Updates to Preview Branch (eng-1426-bug-in-permission-functions) ↗︎

Deployments	Status	Updated
Database	✅	Mon, 16 Feb 2026 14:17:44 UTC
Services	✅	Mon, 16 Feb 2026 14:17:44 UTC
APIs	✅	Mon, 16 Feb 2026 14:17:44 UTC

Tasks are run on every commit but only new migration files are pushed.
Close and reopen this PR if you want to apply changes from existing seed or migration files.

Tasks	Status	Updated
Configurations	✅	Mon, 16 Feb 2026 14:17:45 UTC
Migrations	✅	Mon, 16 Feb 2026 14:17:45 UTC
Seeding	✅	Mon, 16 Feb 2026 14:17:45 UTC
Edge Functions	✅	Mon, 16 Feb 2026 14:17:47 UTC

---

View logs for this Workflow Run ↗︎.
Learn more about Supabase for Git ↗︎.

[mdroidian]

Just make sure to look at: https://github.com/DiscourseGraphs/discourse-graph/pull/778/changes#r2807642747

Also, ignore the linting CI, I'm unsure why it is failing, I will look into adding better reporting.

[devin-ai-integration]

Devin Review found 1 new potential issue.

View 9 additional findings in Devin Review.

[devin-ai-integration]

🔴 LEAST(NULL, ...) returns NULL causing NOT NULL constraint violation on SpaceAccess INSERT

When upsert_account_in_space inserts a new SpaceAccess row for a user who has a dg_account (i.e. user_uid IS NOT NULL), the permissions value is computed as least(my_permissions_in_space(space_id_), COALESCE(permissions_, 'editor')). If the calling user (identified by auth.uid() from the JWT) has no SpaceAccess entry for the space, my_permissions_in_space returns NULL (since max() over an empty set is NULL). In PostgreSQL, LEAST(NULL, 'editor') evaluates to NULL, which violates the NOT NULL constraint on SpaceAccess.permissions (packages/database/supabase/schemas/account.sql:108).

Root Cause and Impact

my_permissions_in_space at packages/database/supabase/schemas/account.sql:228-237 returns:

SELECT max(permissions) FROM public."SpaceAccess"
JOIN public.my_user_accounts() ON (account_uid = my_user_accounts)
WHERE space_id=space_id_;

When no rows match, max() returns NULL.

The INSERT at line 352-353 then computes:

VALUES (space_id_, user_uid, least(my_permissions_in_space(space_id_), COALESCE(permissions_, 'editor')))

LEAST(NULL, 'editor') = NULL → fails with NOT NULL constraint.

The same issue occurs on the ON CONFLICT DO UPDATE path at line 356-357 when permissions_ is not NULL:

ELSE least(my_permissions_in_space(space_id_), permissions_)

In the current main flows, callers authenticate as the anonymous space user (who has 'editor' permissions), so this doesn't manifest. However, if any caller invokes these functions with a JWT for a user who is not yet in the space, or with no JWT (service role), the function will crash instead of producing a meaningful error.

The fix should wrap the LEAST call with a COALESCE, e.g.: COALESCE(my_permissions_in_space(space_id_), permissions_) or add an explicit NULL check and raise a proper error.

Prompt for agents

In packages/database/supabase/schemas/account.sql, in the upsert_account_in_space function (lines 346-358), the LEAST() calls with my_permissions_in_space() can return NULL when the calling user has no SpaceAccess entry. This violates the NOT NULL constraint on SpaceAccess.permissions. Fix both the INSERT VALUES clause (line 352-353) and the ON CONFLICT DO UPDATE clause (line 356-357). Either: (a) add a COALESCE around my_permissions_in_space so that NULL falls back to the requested permissions, e.g. COALESCE(my_permissions_in_space(space_id_), COALESCE(permissions_, 'editor')), or (b) add an explicit check before the INSERT that raises a proper error if my_permissions_in_space returns NULL. Apply the same fix in the migration file packages/database/supabase/migrations/20260213155959_upsert_user_permissions.sql at lines 41 and 45.

---

Was this helpful? React with 👍 or 👎 to provide feedback.