# pubsub
ultra-minimal pubsub module written in TypeScript
## install
```sh
pnpm add @rasch/pubsub
# or with bun
bun add @rasch/pubsub
```
## usage
```js
import { publish, subscribe, unsubscribe } from "@rasch/pubsub"
import { welcome, tryagain } from "./fakeCallbackFunctions.js"
subscribe("login", welcome)
subscribe("loginError", tryagain)
if (user.isLoggedIn()) {
  publish("login", user.name)
} else {
  publish("loginError", `Incorrect username "${user.name}" or password!`)
}
unsubscribe("*")
```
## api
### subscribe
```txt
subscribe :: string -> (...a -> void) -> void
```
Attach a callback function to an event.
```typescript
subscribe("event", myFunction)
```
### publish
```txt
publish :: (string, ...a) -> void
```
Run all of the functions attached to an event with the given arguments.
```typescript
publish("event", arg)
publish("event", arg1, arg2, ...)
```
### unsubscribe
```txt
unsubscribe :: (string, ((...a -> void) | undefined)) -> void
```
Stop listening for events.
```typescript
// stop listening to a single event callback function
unsubscribe("event", myFunction)
// stop listening for all callback functions on event
unsubscribe("event")
// cancel all subscriptions
unsubscribe("*")
```

dist

image: nixos/latest
packages:
  - bun
  - nodejs_20
  - pijul
environment:
  project: pubsub
secrets:
  - 2b8f0d2a-cab9-451d-b684-6b89582fb7b0 # NPM publish token
tasks:
  - setup: |
      pijul clone https://nest.pijul.com/rasch/"$project"
      cd "$project"
      bun install
  - stop_if_not_release: |
      cd "$project"
      current=$(pijul log --limit 1 --state | grep '^State' | cut -d ' ' -f 2)
      tag=$(pijul tag | grep '^State' | cut -d ' ' -f 2)
      test "$current" = "tag" || complete-build
  - release: |
      cd "$project"
      bun run build
      echo '//registry.npmjs.org/:_authToken=${NPM_TOKEN}' >> .npmrc
      set +x
      . ~/.env
      set -x
      npm publish --access public