Request: rule for banning synchronous imports of arbitrary packages

[ryami333]

Managing bundle sizes and enforcing code-splitting in large applications can be delicate, and there is currently no mechanism which I know of to enforce that specific libraries must not be imported with ordinary import moment from 'moment'; syntax, and instead must be split like const momentPromise = import('moment').

Proposed API:

  "rules": {
    "import/no-synchronous-dependencies": ["error", {
      "packages": ['moment', 'zxcvbn']
    }]
  }

Example No. 1, errors:

import moment from 'moment'

Example No. 2, errors:

const moment = require('moment')

Example No. 3, passes

const momentLoader = import('moment')

Would there be an appetite for this? If there would be, I would consider making a PR of my own.

[ljharb]

This already exists overall: no-restricted-imports and no-restricted-modules.

I’d say the import rule could perhaps have an extra config option that indicates whether it’s redtricted for sync, async, or both.

However, both of those are core rules (not in this plugin), import() is stage 3, eslint only supports stage 4 and above, and i don’t think it’d make sense to add an entire rule here when it’d be a simple option in the future in core.