jkso / conducer

Minimal tools for creating rules with conditions using simple reducers.

Conducer

Minimal tools for creating rules with conditions using simple reducers. Conditions are pure functions, so there's no side-effects. Facts must have everything needed by the conditions.

Tools:

They return a single condition function which expects the facts as argument in order to return a boolean.

every([ condition, conditionOne, conditionTwo ])

Every condition (all conditions) must be true.

notEvery([ condition, conditionOne, conditionTwo ])

Every condition can't be true.

some([ condition, conditionOne, conditionTwo ])

Some condition must be true.

notSome([ condition, conditionOne, conditionTwo ])

Some condition can't be true.

Examples:

Simple:

import { every, some } from 'conducer'

export const hasRole = role => ({ user }) => user.roles.some(role)
export const isActiveUser = ({ user: { status } }) => status

const canEditComments = every([
  isActiveUser,
  some([
    hasRole('admin'),
    hasRole('moderator'),
  ])
])

const facts = { user: { status: true, roles: ['moderator', 'admin'] } }

if (canEditComments(facts)) {
  // Give access to edit comments.
}
else {
  // Denied access to editing comments.
}

Using the when() chaining function to avoid if conditions:

import { every, some, when } from 'conducer'

// ... same as above.

when(canEditComments(facts))
  .do(() => {
    // Give access to edit comments.
  })
  .else(() => {
    // Denied access to editing comments.
  })

Usage:

• Tests.

LICENSE

MIT