Function decodeEventMessage

packages/standard-server/src/event-iterator/decoder.ts:4–50

(encoded: string)

import { EventDecoderError } from './errors'

export function decodeEventMessage(encoded: string): EventMessage {
  const lines = encoded.replace(/\n+$/, '').split(/\n/)

  const message: EventMessage = {
    data: undefined,
    event: undefined,
    id: undefined,
    retry: undefined,
    comments: [],
  }

  for (const line of lines) {
    const index = line.indexOf(':')

    const key = index === -1 ? line : line.slice(0, index)
    const value = index === -1 ? '' : line.slice(index + 1).replace(/^\s/, '')

    if (index === 0) {
      message.comments.push(value)
    }

    else if (key === 'data') {
      message.data ??= ''
      message.data += `${value}\n`
    }

    else if (key === 'event') {
      message.event = value
    }

    else if (key === 'id') {
      message.id = value
    }

    else if (key === 'retry') {
      const maybeInteger = Number.parseInt(value)

      if (Number.isInteger(maybeInteger) && maybeInteger >= 0 && maybeInteger.toString() === value) {
        message.retry = maybeInteger
      }
    }
  }

  message.data = message.data?.replace(/\n$/, '')

  return message
}

export interface EventDecoderOptions {
  onEvent?: (event: EventMessage) => void