| 1 | /** |
| 2 | * Channel names and direct-message keys. Pure, so they are tested apart |
| 3 | * from the service. |
| 4 | */ |
| 5 | |
| 6 | /** The longest channel name. */ |
| 7 | export const MAX_NAME = 80; |
| 8 | |
| 9 | /** The most members a direct message may have, the viewer included. */ |
| 10 | export const MAX_DM_MEMBERS = 9; |
| 11 | |
| 12 | /** The channel every workspace starts with. */ |
| 13 | export const GENERAL = "general"; |
| 14 | |
| 15 | const NAME = /^[a-z0-9_-]+$/; |
| 16 | |
| 17 | /** |
| 18 | * Names the site's chat URLs use beside channel names |
| 19 | * (`/<workspace>/-/chat/<name>`), so no channel can take them. |
| 20 | */ |
| 21 | export const RESERVED = new Set(["dm", "browse", "live", "api", "new"]); |
| 22 | |
| 23 | /** |
| 24 | * A channel name as it is kept: lowercase, without a leading `#`, spaces |
| 25 | * as dashes. Names are what people type after `#`, so only letters, |
| 26 | * digits, `-` and `_`. |
| 27 | */ |
| 28 | export function channelName(input: string): { ok: true; name: string } | { ok: false; message: string } { |
| 29 | const name = String(input ?? "") |
| 30 | .trim() |
| 31 | .replace(/^#+/, "") |
| 32 | .toLowerCase() |
| 33 | .replace(/\s+/g, "-"); |
| 34 | if (!name) return { ok: false, message: "A channel needs a name." }; |
| 35 | if (name.length > MAX_NAME) return { ok: false, message: `A channel name is at most ${MAX_NAME} characters.` }; |
| 36 | if (!NAME.test(name)) { |
| 37 | return { ok: false, message: "A channel name can only use lowercase letters, digits, dashes and underscores." }; |
| 38 | } |
| 39 | if (RESERVED.has(name)) return { ok: false, message: `#${name} is reserved. Pick another name.` }; |
| 40 | return { ok: true, name }; |
| 41 | } |
| 42 | |
| 43 | /** |
| 44 | * Who is in a direct message: the viewer and `others`, each once, sorted. |
| 45 | * Nobody else, or only the viewer, is a direct message with yourself: |
| 46 | * a place for notes. |
| 47 | */ |
| 48 | export function dmMembers(viewer: string, others: string[]): string[] { |
| 49 | return [...new Set([viewer, ...others])].sort(); |
| 50 | } |
| 51 | |
| 52 | /** The key that finds a direct message by its members, whatever order they were given in. */ |
| 53 | export function dmKey(members: string[]): string { |
| 54 | return [...new Set(members)].sort().join(","); |
| 55 | } |