eslint-plugin-ts-import

^{Define specific import rules for files within your Typescript project. Adapted and enhanced from VSCode's code-import-patterns}

yarn add --dev eslint-plugin-ts-import

Features

• Provide import patterns that restrict imports of certain files based on location.
• Ensure imports meet the expected guidelines within your repo.
• Adapted from VSCode's rule code-import-patterns.
• Works with configured paths from your tsconfig.json
• Provide custom eslint messaging for each pattern if needed.
• Useful in monorepos and most Typescript projects which utilize incremental builds.

Simple Example

// .eslintrc.js

module.exports = {
  root: true,
  parser: '@typescript-eslint/parser',
  rules: {
    'ts-import/patterns': [
      'error',
      {
        // these rules apply to any files which are within the src/services directory
        target: '**/src/services/*/**',

        // allow any imports to node_modules.  We confirm that the node_module exists in case the use of paths / absolute imports is used so that
        // we can tell the difference
        modules: true,

        // allow imports of node core modules?  defaults to true.  if false, imports like fs, path, stream will cause an error
        node: true,

        allowed: [
          // anything in src/services/{service}/** may import config `import config from 'config'`
          'config',

          // anything in src/services/{service}/** may import from core `import someModule from 'core/someModule'`
          'core/**',

          // run target.replace(arr[0], arr[1]) to build pattern
          // any service may import from itself - so src/services/rest-api/** may always import from `src/services/rest-api/**`
          // whether using relative or absolute imports.  However it will not be able to import from `../api-client/**` or `services/api-client/**`
          [/.*\/src\/services\/([^/]*)\/.*/, '**/src/services/$1/**'],

          // allow any imports whether relative or absolute as long as they are not higher than /src/services
          [/(.*\/src\/services).*/, '$1/**'],

          // this rule without the above rule would only allow the files to import themselves or higher and would restrict `../`
          './**',
        ],
        message:
          'Optional custom message to display when violated',
      },
    ],
  },
  plugins: ['ts-import']
}

Special Thanks

• While originally utilizing custom logic, we since borrowed the resolving method used by eslint-import-resolver-typescript.