`Scheduler detected unresolved dependencies` `v0.5.0`

[boyswan]

• I've validated the bug against the latest version of DB packages

When trying to run an optimistic action on an electric collection, I get this error.

Uncaught Error: Scheduler detected unresolved dependencies for context 1efbf3e1-41e3-4201-9f42-da1f38ec6ae9.

This only seems to happen when mutating the draft object.

To Reproduce

const someCollection = createCollection(
  electricCollectionOptions({
   ...
  })
)

const testAction = createOptimisticAction<string>({
  onMutate: id => {
   someCollection.update(id, draft => {
      draft.name = 'new name here';
    });
  },
  mutationFn: async (id, _params) => {
    return { txid: 0 };
  }
});

...
testAction("1efbf3e1-41e3-4201-9f42-da1f38ec6ae9")

Disabling optimistic update prevents the error:

 someCollection.update(id, { optimistic: false }, draft => {
      draft.name = 'new name here';
    });

However this obviously defeats the point!

[samwillis]

Hi @boyswan, I don't suppose you could share some more code that triggered this error. Do you have any complex joins, multiple live queries, or live queries that depend on others?

The schedular is used to ensure that we only rerun the live queries as few time as possible when a change to one or more collections is made in a single transaction. This is an error that is intended to never happen, you've likely found an edge case where it can be triggered.

[boyswan]

I do have a quite a few complex joins (perhaps not idiomatic but they "work"), and have found an example of what causes this issue.

const accountCollection = ...
const userCollection = ...
const teamCollection = ...

const accountsWithUserCollection = createLiveQueryCollection((q) => q
  .from({ account: accountCollection })
  .join({ user: userCollection }, ({ user, account }) => eq(user.id, account.user_id))
  .select(({ account, user }) => ({
    account: account,
    profile: user?.profile
  }))
)

const activeTeamsCollection = createLiveQueryCollection((q) => q
  .from({ team: teamCollection })
  .where(({ team }) => isNull(team.deleted_ts))
  .select(({ team }) => ({ team: team }))
)

const accountsWithTeamsCollection = createLiveQueryCollection((q) => q
  .from({ accountWithUser: accountsWithUserCollection })
  .leftJoin({ team: activeTeamsCollection }, ({ accountWithUser, team }) => eq(team.team.account_id, accountWithUser.account.id))
  .select(({ accountWithUser, team }) => ({
    account: accountWithUser.account,
    profile: accountWithUser.profile,
    team: team?.team
  }))
)

export const useAccount = (id: string | undefined) => {
  const { data } = useLiveQuery((q) => q
    .from({ accountWithScenario: accountsWithTeamsCollection })
    .where(({ accountWithScenario }) => eq(accountWithScenario.account.id, id ?? '')),
    [id]
  )
  return data
}

The culprit in this case seems to be the left join. Removing this prevents schedule error.

const accountsWithTeamsCollection = createLiveQueryCollection((q) => q
  .from({ accountWithUser: accountsWithUserCollection })
  // .leftJoin({ team: activeTeamsCollection }, ({ accountWithUser, team }) => eq(team.team.account_id, accountWithUser.account.id))
  .select(({ accountWithUser }) => ({
    account: accountWithUser.account,
    profile: accountWithUser.profile,
    team: {} as any
  }))
)

[samwillis]

Thanks @boyswan, this is going to massively help with narrowing down the exact internal cause!