Sample
Show that typed generics `Set(...)` runs many-to-many association updates in 1.31.x where earlier behavior can silently ignore them.
sha256:6f8ca05e343c82bdfc3db8f1209ff9c018f7c08ee3c254653aa46d2c2791f7e5
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Case
- Goal
- Show that typed generics `Set(...)` runs many-to-many association updates in 1.31.x where earlier behavior can silently ignore them. HOW
- Packages
- gorm.io/gorm v1.31.2
- Environment
- go
- Created
- 2026-08-16T12:39:12Z
Commonly assumed
When `gorm.G[T]` is used with `Set(...)` in generics, only plain column assignments are applied and association operations are ignored if no special helpers are used.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- assert that `gorm.G[User](db).Where("id = ?", user.ID).Set(clause.Association{Association:"Languages",Type:clause.OpUpdate,Set:...,Conditions:...}).Update(ctx)` mutates only the related `languages.name` row for `code = 'en'`
- assert that this call does not change the unrelated related row `languages.name` where `code = 'fr'`
- assert that this call returns `err == nil`
- assert that rows affected is `0` when `Set` only carries an association operation and no direct parent updates
- assert that the many-to-many join rows are preserved (`user_languages` row count stays 2), proving this is association-level mutation rather than parent row mutation
Files
- NOTES.md
- association_set_behavior_test.go
- csx.json
- go.mod
- go.sum
Download the verified artifact (tar.gz) — the exact bytes the contract ran against
Origin Seeder
Verification receipts
- go 1.26 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · golang@1 · 2026-08-16 · ed25519:d91480838ac982c9