Function parseEventStreamLine

packages/experimental/src/Sse.ts:191–242

(
    lineBuffer: string,
    index: number,
    fieldLength: number,
    lineLength: number
  )

  }

  function parseEventStreamLine(
    lineBuffer: string,
    index: number,
    fieldLength: number,
    lineLength: number
  ) {
    if (lineLength === 0) {
      // We reached the last line of this event
      if (data.length > 0) {
        onParse({
          _tag: "Event",
          id: eventId,
          event: eventName ?? "message",
          data: data.slice(0, -1) // remove trailing newline
        })
        data = ""
        eventId = undefined
      }
      eventName = undefined
      return
    }

    const noValue = fieldLength < 0
    const field = lineBuffer.slice(index, index + (noValue ? lineLength : fieldLength))
    let step = 0

    if (noValue) {
      step = lineLength
    } else if (lineBuffer[index + fieldLength + 1] === " ") {
      step = fieldLength + 2
    } else {
      step = fieldLength + 1
    }

    const position = index + step
    const valueLength = lineLength - step
    const value = lineBuffer.slice(position, position + valueLength).toString()

    if (field === "data") {
      data += value ? `${value}\n` : "\n"
    } else if (field === "event") {
      eventName = value
    } else if (field === "id" && !value.includes("\u0000")) {
      eventId = value
      lastEventId = value
    } else if (field === "retry") {
      const retry = parseInt(value, 10)
      if (!Number.isNaN(retry)) {
        onParse(new Retry({ duration: Duration.millis(retry), lastEventId }))
      }
    }
  }
}

const BOM = [239, 187, 191]