[#412] frint-config/Typescript

[adrw]

Unsure how to get past the below typing error so I added rudimentary Typescript support just with any for function-returned arrays of externals.

Issue

Consider if there was a type External.

declare type External = {
  root: string|string[]|Array<string>;
  commonjs: string;
  commonjs2: string;
  amd: string;
}

From my research, there doesn't seem to be a way to define a further type that is an object of strings mapping to External.

let lodashExternal : External = {
      root: '_',
      commonjs: 'lodash',
      commonjs2: 'lodash',
      amd: 'lodash',
   }

let rxjsExternal : External = { ... }

export const thirdParties = [{
  'lodash': lodashExternal,
  'rxjs': rxjsExternal,
    ...
]

In the example above, though it is clear that the const thirdParties consists of named External objects, how can this type be defined without explicitly defining each library?

export declare type Externals = [{
  'lodash'?: External,
  'rxjs'?: External,
  'react'?: External,
  'react-dom'?: External,
  'prop-types'?: External,
  'frint'?: External,
  'frint-store'?: External,
  'frint-model'?: External,
  'frint-data'?: External,
  'frint-react'?: External,
  'frint-router'?: External,
  'frint-router-react'?: External,
...
}

[fahad19]

Thanks for the PR, @andrewparadi!

TypeScript also supports any for keys. for example, in this interface:

interface Foo {
  [key: string]: any;
}

It means, any object implementing the Foo interface can have any keys which is a string, which any value.

[fahad19]

Refs #412