createOptimisticEventSchema

const createOptimisticEventSchema: ({ valueSchema, defaultValue, partialSet, }) => Schema.Codec<any, unknown>

Defined in: packages/@livestore/common/dist/schema/state/sqlite/client-document-def.d.ts:55

Creates an optimistic schema that accepts historical event formats and transforms them to the current schema, preserving data and intent.

Decision Matrix for Schema Changes:

Change Type	Partial Set	Full Set	Strategy
Compatible Changes
Add optional field	Preserve existing	Preserve existing, new field undefined	Direct decode or merge
Add required field	Preserve existing	Preserve existing, new field from default	Merge with defaults
Incompatible Changes
Remove field	Drop removed field	Drop removed field, preserve others	Filter & decode
Type change	Use default for field	Use default for changed field	Selective merge
Rename field	Use default	Use default (can’t detect rename)	Fall back to default
Edge Cases
Empty event	Return {}	Return full default	Fallback handling
Invalid structure	Return {}	Return full default	Fallback handling

Parameters

{ valueSchema, defaultValue, partialSet, }

defaultValue

any

partialSet

boolean

valueSchema

Schema.Codec<any, any>

Returns

Schema.Codec<any, unknown>