@ayaseaki/swc-plugin-monorepo-relative-path-resolve

A SWC plugin to handle resolving relative import paths like @/* and @common/* of sub-packages in a monorepo.

Why

For monorepo scene, we often have the need to directly import the source code of sub-packages to get a better bundle speed.

However, when a sub-package in a monorepo has its own path alias defined in its tsconfig.json, the bundle of base app may not respect the alias config, which results in a failure of resolution:

// sub-package/src/index.ts
import { foo } from '@/common/constants';
export { foo };

// sub-package/src/common/constants.ts
export const foo = 'foo';

// base/index.ts
import { foo } from 'sub-package'; 
console.log(foo);

// while compiling base/index.ts `Can't resolve @/common/constants` will be thrown

This plugin aims to resolve a subset of this issue: if your alias is just a relative of src path, you can use this swc plugin to dynamically replace the import alias during compile-time.

Usage

pnpm i -D @ayaseaki/swc-plugin-monorepo-relative-path-resolve

This plugin can handle the import source matching {prefix}{subpath}?/. For example:

• @/*
• @common/*
• ~common/*

Usage with rspack:

// in rspack.config.js (ts):
{
  test: /\.(jsx?|tsx?)$/,
  use: [
    {
      loader: "builtin:swc-loader",
      options: {
        jsc: {
          // ...
          // add the following config:
          experimental: {
            plugins: [
              [
                "@ayaseaki/swc-plugin-monorepo-relative-path-resolve",
                {
                  prefix: "@",
                  allowedPathnames: ["common"],
                },
              ],
            ],
          },
        },
      },
    },
  ],
},

See example for detail.

Configration

prefix

• type: string
• description: specify the import prefix of your code.
• default: @

allowedPathnames

• type: string[]
• description: specify the allowed pathnames after prefix, for example if you have a relative path @common/ and @components/, then you set allowedPathnames to ['common', 'components'.]
• default: []