event-schema-missing

The request leaves out the schema to register.

Route: register-event-schema
Description: event schema is missing: expected a JSON schema with type 'object'
Details: None; details is an empty object.

Why It Happens#

Registering a schema takes the event type in type and the JSON Schema in schema, and the request leaves out schema, for example because the client code had no schema at hand: in JavaScript, JSON.stringify leaves out a field whose value is undefined. A schema that is null or not a JSON object is rejected with 400 Bad Request instead, since the body then does not have the shape the route expects.

The event type is checked first, so a request that lacks both is reported as event-type-missing.

How to Fix It#

Send the schema in schema, as a JSON Schema with "type": "object" at its top level. Sending the same request again fails the same way, since the error depends on the request alone.

Example#

To register a schema for io.eventsourcingdb.library.book-acquired with a request that leaves out schema, EventSourcingDB answers with this error, as a line of the stream, and then ends the stream with its end item:

{
  "type": "error",
  "data": {
    "code": "https://docs.eventsourcingdb.io/errors/event-schema-missing",
    "description": "event schema is missing: expected a JSON schema with type 'object'",
    "details": {}
  }
}