Support TypeScript 4.1

[talohana]

TypeScript 4.1 adds an option to use path mapping without specifying baseUrl, more about it in TypeScript 4.1 Release Notes

My project is using TypeScript 4.1.2, trying to remove the baseUrl I get the following error

Failed to load tsconfig.json: Missing baseUrl in compilerOptions tsconfig-paths-webpack-plugin: Found no baseUrl in tsconfig.json, not applying tsconfig-paths-webpack-plugin

Would like to submit a PR with a little help :)

[jakebailey]

See also: dividab/tsconfig-paths#143, https://github.com/dividab/tsconfig-paths-webpack-plugin/issues/32#issuecomment-695134747

[jakebailey]

Since 4.1, I've worked around this with secondary configs that extend and add a baseUrl; after hitting more bugs like #60, I've found that it's easier to drop the plugin in favor of a little code that transforms the paths config into webpack resolve aliases; the output is identical to the tsconfig-paths plugin (when it's working).

[7iomka]

@jakebailey

Hi, share please your solution / example repo? I have similar issues

[jakebailey]

Sure, the function I wrote to generate aliases is here: https://github.com/microsoft/pyright/blob/169c6089b9914870c43622743c75844657cd9d70/build/lib/webpack.js#L90

resolve.alias gets set to the return value of this function.

As far as I can tell, this is all you need to support tsconfig paths. It verifies enough to make the file ts-check (hence the asserts), but otherwise is all that's really needed to make paths work, no plugin needed.

[7iomka]

https://github.com/microsoft/pyright/blob/169c6089b9914870c43622743c75844657cd9d70/build/lib/webpack.js#L90

resolve: {
            extensions: ['.ts', '.js'],
            alias: tsconfigResolveAliases('tsconfig.json'),
        },

That is enough?

[jakebailey]

Correct.

[7iomka]

Correct.

With storybook it is correct usage?

  webpackFinal: async (config) => {
    // resolve problem with typescript aliases
    config.resolve.alias = {
      ...config.resolve?.alias,
      ...tsconfigResolveAliases('../tsconfig.json'),
    };
  ....
}

[jakebailey]

I have no idea what storybook is, but I don't see why not. Can't hurt to try.

[7iomka]

I have no idea what storybook is, but I don't see why not. Can't hurt to try.

I have that config

{
  "extends": "./tsconfig/nextjs.json",
  "include": ["."],
  "exclude": ["dist", "build", "node_modules"]
}

With JSONC you parse content of file and compilerOptions required inside. Any workaround for that kind of configs? filepath on the field extends may have similar extends (That is how monorepo configs structured)

[jakebailey]

Last I looked, paths is not a config that is carried over from the extended config, so if your project doesn't copy/paste paths around, they aren't working correctly in the first place, and my snippet is still doing the right thing by not following extended paths. The project that uses my little helper (pyright and Pylance) are forced to duplicate them in every tsconfig.