EventGroup.ts

EventGroup.ts overview

Defines groups of typed events for the unstable event-log system.

An EventGroup collects event definitions that belong together. Start with empty, add events with their payload, success, and error schemas, then use the group to build clients with EventLog.schema and server handlers with EventLog.group. The group only describes events; it does not write or run them.

Since v4.0.0

---

Exports Grouped by Category

• constructors
  • empty
• guards
  • isEventGroup
• models
  • Any (interface)
  • AnyWithProps (type alias)
  • EventGroup (interface)
  • Events (type alias)
  • ServicesClient (type alias)
  • ServicesServer (type alias)
  • ToService (type alias)
• type IDs
  • TypeId
  • TypeId (type alias)

---

constructors

empty

Creates an empty event group used as the starting point for defining a group.

When to use

Use when you need the starting EventGroup value before adding event definitions with .add(...).

Signature

declare const empty: EventGroup<never>

Source

Since v4.0.0

guards

isEventGroup

Returns true when a value is an event log event group.

Signature

declare const isEventGroup: (u: unknown) => u is Any

Source

Since v4.0.0

models

Any (interface)

Type-erased marker for an event log event group.

Signature

export interface Any {
  readonly [TypeId]: TypeId
}

Source

Since v4.0.0

AnyWithProps (type alias)

Type-erased event group with its events record available structurally.

Signature

type AnyWithProps = EventGroup<Event.Any>

Source

Since v4.0.0

EventGroup (interface)

Typed collection of event definitions that represents a portion of an event log domain.

When to use

Use when build groups from empty.add(...), then provide implementations for the events with EventLog.group.

Signature

export interface EventGroup<out Events extends Event.Any = Event.Any> extends Pipeable {
  readonly [TypeId]: TypeId
  readonly events: Record.ReadonlyRecord<string, Events>

  /**
   * Add an `Event` to the `EventGroup`.
   */
  add<
    Tag extends string,
    Payload extends Schema.Top = typeof Schema.Void,
    Success extends Schema.Top = typeof Schema.Void,
    Error extends Schema.Top = typeof Schema.Never
  >(options: {
    readonly tag: Tag
    readonly primaryKey: (payload: Schema.Schema.Type<Payload>) => string
    readonly payload?: Payload
    readonly success?: Success
    readonly error?: Error
  }): EventGroup<Events | Event.Event<Tag, Payload, Success, Error>>

  /**
   * Add an error schema to all the events in the `EventGroup`.
   */
  addError<Error extends Schema.Top>(error: Error): EventGroup<Event.AddError<Events, Error>>
}

Source

Since v4.0.0

Events (type alias)

Extracts the union of event definitions contained in an event group.

Signature

type Events<Group> = Group extends EventGroup<infer _Events> ? _Events : never

Source

Since v4.0.0

ServicesClient (type alias)

Client-side schema services required by all events in an event group.

Signature

type ServicesClient<Group> = Event.ServicesClient<Events<Group>>

Source

Since v4.0.0

ServicesServer (type alias)

Server-side schema services required by all events in an event group.

Signature

type ServicesServer<Group> = Event.ServicesServer<Events<Group>>

Source

Since v4.0.0

ToService (type alias)

Derives the handler service markers required for all events in an event group.

Signature

type ToService<A> = A extends EventGroup<infer _Events> ? Event.ToService<_Events> : never

Source

Since v4.0.0

type IDs

TypeId

Runtime type identifier used to mark event log event groups.

Signature

declare const TypeId: "~effect/eventlog/EventGroup"

Source

Since v4.0.0

TypeId (type alias)

Unique type identifier used to mark event log event groups.

Signature

type TypeId = "~effect/eventlog/EventGroup"

Source

Since v4.0.0