Definitelytyped types for system-node.cjs

[tbrannam]

• SystemJS Version:
• Which library are you using?
  • system.js
  • s.js
  • system-node.cjs
• Which extras are you using?
  • AMD extra
  • Named Exports
  • Named Register
  • Transform
  • Use Default
  • Global
  • Dynamic Import Maps
• Are you using any custom hooks?

Question

I am uncertain where to raise this issue, as npm package @types/systemjs is not maintained here, but was hoping that @joeldenning would have visibility here.

When building for a Node target, and and importing system-node.cjs, and including @types/systemjs as a dependency.

import SystemNode from 'systemjs/dist/system-node.cjs' 

Then systemjs/dist/system-node.cjs it not recognized as a typescript module and is untyped. Additionally the Typescript types that do exist do not include applyImportMap which is only available in system-node.cjs.

Are there examples that could be cited which demonstrate the usage of TS types with system-node.cjs ?

[tbrannam]

So the simplest thing I could come up with looks like this in a local file

system-node.d.ts

/// <reference types="systemjs" />

declare module 'systemjs/dist/system-node.cjs' {
  type SystemJS = typeof System & {
    constructor: new () => SystemJS
  }

  const _System: SystemJS

  export { _System as System }

  export function applyImportMap(
    system: typeof System,
    importMap: System.ImportMap
  ): void
}


// if using Webpack and referencing the module context in a SystemJS Module
declare const __system_context__: System.Context

and usage wise

import SystemPkg  from 'systemjs/dist/system-node.cjs'
const { System, applyImportMap } = SystemPkg

const anotherSystemInstance = new System.contructor()
applyImportMap(anotherSystemInstance, { /* importmap *? })