Anvia

Splitting and validation ​

Adapters own their platform text limits; the shared package provides the splitting helpers and the portable payload validators they all build on. See Channel core for the full utility map.

Splitting and platform limits ​

Each adapter owns its platform's text limit through splitMessage(). The package exports the two helpers adapters build on: splitChannelText() splits plain text, and splitChannelMessage() splits a complete portable message:

ts
import { splitChannelMessage, splitChannelText } from '@anvia/channel'

const textParts = splitChannelText({ text: longReport, maximumLength: 2_000 })
const parts = splitChannelMessage({ message, maximumLength: 2_000 })

Splitting behavior:

  • Boundaries prefer readability: the last newline before the limit, then the last space, then a hard cut.
  • maximumLength must be a positive safe integer (TypeError otherwise); a maximumLength too small to hold one Unicode character throws a RangeError.
  • Empty text throws a TypeError; a media-only message (text: '' plus attachments) becomes a single part.
  • replyToMessageId is copied to every part.
  • actions and attachments are placed only on the final part.

Runtime validation ​

sendChannelMessage() validates actions and attachments up front, and every platform send() validates again before delivery. Call the validators yourself when you build UI constraints or accept user-supplied payloads:

ts
import {
  validateChannelActions,
  validateChannelAttachments,
  validateChannelMessage,
} from '@anvia/channel'

validateChannelMessage(message) // checks actions and attachments
validateChannelActions(message.actions)
validateChannelAttachments(message.attachments)

The validators throw a TypeError for malformed values and a RangeError for limit violations. The portable limits:

  • At most 5 actions per message (MAX_CHANNEL_ACTIONS).
  • Action labels contain between 1 and 80 characters (MAX_CHANNEL_ACTION_LABEL_LENGTH).
  • Action IDs are non-empty and unique within a message (TypeError when empty or duplicated) and at most 64 UTF-8 bytes (RangeError when overlong; isChannelActionId() checks the shape).
  • Action style is 'default', 'primary', or 'danger' (default when omitted); anything else throws a TypeError.
  • At most 10 outbound attachments per logical message (MAX_CHANNEL_ATTACHMENTS).
  • Attachment url sources must use HTTPS; data sources must be valid base64. mediaType must be non-empty, filename non-empty when present, and size a non-negative safe integer when present.
  • When present, actions and attachments must be non-empty arrays.

validateChannelMessage() checks only actions and attachments — it does not validate text length, which is the adapter's splitMessage() job. Use the exported MAX_CHANNEL_* constants when an application UI needs to enforce the same limits.

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Built for Anvia.