fix: Made field-less Schema.Struct({}) respect onExcessProperty: 'ignore' | 'preserve' | 'error'

[nikelborm]

Type

• Refactor
• Feature
• Bug Fix
• Optimization
• Documentation Update

Description

Motivation: you remove one field in the schema; the decoded object gets fewer fields. You remove another; fewer again. You remove the last; suddenly, all the fields come back, regardless of the default onExcessProperty: "ignore". If the user wants to retrieve all fields, they can set onExcessProperty: "preserve".

I tried to defend old behavior with "{} means typeof obj === 'object' && obj !== null and effect's schema tries to be closer to TypeScript's behaviour, by treating Schema.Struct({}) as something passing the condition". And this might hold in isolation. But considering the context, by this logic, any fields which are not explicitly mentioned in Schema.Struct({ ... }) should be preserved in all decoded objects, not only the ones that have {} signature, to follow TypeScript's assignability rules. And this is not what happens. The behavior should be consistent between field-less and field-ful structs.

Related

• v3 fix: Made field-less Schema.Struct({}) respect onExcessProperty: 'ignore' | 'preserve' | 'error' effect#6298

[changeset-bot]

🦋 Changeset detected

Latest commit: 3c65513

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 27 packages

Name	Type
effect	Patch
@effect/opentelemetry	Patch
@effect/platform-browser	Patch
@effect/platform-bun	Patch
@effect/platform-node-shared	Patch
@effect/platform-node	Patch
@effect/vitest	Patch
@effect/ai-anthropic	Patch
@effect/ai-openai-compat	Patch
@effect/ai-openai	Patch
@effect/ai-openrouter	Patch
@effect/atom-react	Patch
@effect/atom-solid	Patch
@effect/atom-vue	Patch
@effect/sql-clickhouse	Patch
@effect/sql-d1	Patch
@effect/sql-libsql	Patch
@effect/sql-mssql	Patch
@effect/sql-mysql2	Patch
@effect/sql-pg	Patch
@effect/sql-pglite	Patch
@effect/sql-sqlite-bun	Patch
@effect/sql-sqlite-do	Patch
@effect/sql-sqlite-node	Patch
@effect/sql-sqlite-react-native	Patch
@effect/sql-sqlite-wasm	Patch
@effect/openapi-generator	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[IMax153]

Hi @nikelborm,

The Effect V4 codebase has been merged back into Effect-TS/effect, where V4 development now continues on the main branch.

GitHub cannot transfer pull requests between repositories. If you would like to continue this contribution, please open a replacement pull request against Effect-TS/effect:main and include a link to this PR for its existing discussion and review history.

After opening the replacement, please reply here with its URL so maintainers can verify the migration and close this source PR.

[nikelborm]

I had a mirror PR opened against v3 Effect-TS/effect#6298

Should I close it and create a new one, or should I overwrite the changes in that one?

[IMax153]

@nikelborm - the Effect v3 codebase still lives on the v3 branch - all PRs (including yours) that were opened prior to the v4 codebase merger have been re-targeted to the v3 branch.

So I would suggest opening a companion PR targeting main (i.e. the v4 codebase).