Rollup automatically set dependencies to external

auto-external.js

import pkg from './package.json'

export function autoExternal() {
  return {
    name: 'auto-external',
    options(opts) {
      const deps = [
        ...Object.keys(pkg.dependencies),
        ...Object.keys(pkg.peerDependencies)
      ]

      const external = (id, ...args) => {
        // Bwlow adapted from https://github.com/rollup/rollup/blob/02954f5628bf8e9db57de823e92322d450f0fab4/src/utils/options/normalizeInputOptions.ts#L120-L140
        if (opts.external === true) {
          return true
        }

        if (typeof opts.external === 'function' && opts.external(id, ...args)) {
          return true
        }

        if (opts.external) {
          const externalArray = Array.isArray(opts.external)
            ? opts.external
            : [opts.external]

          const ids = new Set()
          const matchers = []

          for (const value of externalArray) {
            if (value instanceof RegExp) {
              matchers.push(value)
            } else {
              ids.add(value)
            }
          }

          if (ids.has(id) || matchers.some((matcher) => matcher.test(id))) {
            return true
          }
        }

        return deps.some((dep) => id.startsWith(dep))
      }

      return { ...opts, external }
    }
  }
}