TS type for Entry error

[ebuchmann]

Bug report

What is the current behavior?

Typing error with the following:

import { Configuration } from 'webpack';

const configuration = (): Configuration => {
  const webpackConfig = {
    mode: 'development' as const,
    entry: ['webpack-hot-middleware/client', path.join(__dirname, '..', 'client', 'index.jsx')],
    plugins: [
      new HtmlWebPackPlugin({
        title: config.pageTitle,
        template: path.join(__dirname, '..', 'client', 'index.html'),
        filename: path.join(__dirname, '..', 'client', 'index.html'),
      }),
      new webpack.HotModuleReplacementPlugin(),
    ],
    output: {
      filename: '[name].bundle.js',
      path: path.resolve(__dirname, '..', 'client'),
      publicPath: config.basePath,
    },
  };

  return webpackConfig;
};

  Types of property 'entry' are incompatible.
    Type 'string[]' is not assignable to type 'string | (() => string | EntryObject | [string, ...string[]] | Promise<EntryStatic>) | EntryObject | [string, ...string[]] | undefined'.
      Property '0' is missing in type 'string[]' but required in type '[string, ...string[]]'.ts(2345)

The typing for Entry:

type Entry =
	| string
	| (() => string | EntryObject | [string, ...string[]] | Promise<EntryStatic>)
	| EntryObject
	| [string, ...string[]];

If the current behavior is a bug, please provide the steps to reproduce.

What is the expected behavior?

The code works fine, the typing shouldn't be throwing an error for something that is valid. It seems the last part of the typing should just be string[], which works fine if I adjust it manually.

Other relevant information:
webpack version: webpack 5 beta 18
Node.js version: 12
Operating System: macos
Additional tools: vscode

[sokra]

You could try that:

-entry: ['webpack-hot-middleware/client', path.join(__dirname, '..', 'client', 'index.jsx')],
+entry: ['webpack-hot-middleware/client', path.join(__dirname, '..', 'client', 'index.jsx')] as const,

[alexander-akait]

Answer above

[ebuchmann]

I did try that, didn't work. For now I just have to @ts-ignore the line because it doesn't like the typing of [string, ...string[]].

[alexander-akait]

/cc @sokra I think it is bug, here infromation microsoft/TypeScript#30798

[mitchell-frost]

Can I work on this issue?

[alexander-akait]

Yes, PR welcome

[mitchell-frost]

How do I reproduce the bug and where are the changes supposed to be made?

[alexander-akait]

Example above

[sokra]

We can workaround that problem omitting minLength from the Schema for generating type declarations

See webpack/tooling repo

[mitchell-frost]

I created a simple webpack project with the documentation here https://webpack.js.org/guides/getting-started/ and copied and pasted the code above. I don't understand where the code for the type entry is supposed to be. i could not reproduce the bug with npx webpack or npm run build . Is there some other process involved in reproducing it?

[moltar]

Also having a similar issue.

I'm defining an entry in a variable:

const entry: Record<string, string[]> = {
  foo: ['bar', 'baz']
}

But when I supply this to configuration, get the following:

Type 'Record<string, string[]>' is not assignable to type 'Entry'.
  Type 'Record<string, string[]>' is not assignable to type 'string'.ts(2322)

types.d.ts(1790, 2): The expected type comes from property 'entry' which is declared here on type 'Configuration'

[alexander-akait]

Fixed https://github.com/webpack/webpack/releases/tag/v5.3.1