v4.5.0

Minor Changes

• #192 fbf639b Thanks @SukkaW! - The PR implements the new resolver design proposed in #40 (comment)

  For eslint-plugin-import-x users

  Like the ESLint flat config allows you to use js objects (e.g. import and require) as ESLint plugins, the new eslint-plugin-import-x resolver settings allow you to use js objects as custom resolvers through the new setting import-x/resolver-next:

  // eslint.config.js
  import { createTsResolver } from '#custom-resolver';
  const { createOxcResolver } = require('path/to/a/custom/resolver');
  
  const resolverInstance = new ResolverFactory({});
  const customResolverObject = {
    interfaceVersion: 3,
    name: 'my-custom-eslint-import-resolver',
    resolve(modPath, sourcePath) {
      const path = resolverInstance.resolve(modPath, sourcePath);
      if (path) {
        return {
          found: true,
          path
        };
      }
  
      return {
        found: false,
        path: null
      }
    };
  };
  
  module.exports = {
    settings: {
      // multiple resolvers
      'import-x/resolver-next': [
        customResolverObject,
        createTsResolver(enhancedResolverOptions),
        createOxcResolver(oxcOptions),
      ],
      // single resolver:
      'import-x/resolver-next': [createOxcResolver(oxcOptions)]
    }
  }

  The new import-x/resolver-next no longer accepts strings as the resolver, thus will not be compatible with the ESLint legacy config (a.k.a. .eslintrc). Those who are still using the ESLint legacy config should stick with import-x/resolver.

  In the next major version of eslint-plugin-import-x (v5), we will rename the currently existing import-x/resolver to import-x/resolver-legacy (which allows the existing ESLint legacy config users to use their existing resolver settings), and import-x/resolver-next will become the new import-x/resolver. When ESLint v9 (the last ESLint version with ESLint legacy config support) reaches EOL in the future, we will remove import-x/resolver-legacy.

  We have also made a few breaking changes to the new resolver API design, so you can't use existing custom resolvers directly with import-x/resolver-next:

  // When migrating to `import-x/resolver-next`, you CAN'T use legacy versions of resolvers directly:
  module.exports = {
    settings: {
      // THIS WON'T WORK, the resolver interface required for `import-x/resolver-next` is different.
      'import-x/resolver-next': [
         require('eslint-import-resolver-node'),
         require('eslint-import-resolver-webpack'),
         require('some-custom-resolver')
      ];
    }
  }

  For easier migration, the PR also introduces a compat utility importXResolverCompat that you can use in your eslint.config.js:

  // eslint.config.js
  import eslintPluginImportX, { importXResolverCompat } from 'eslint-plugin-import-x';
  // or
  const eslintPluginImportX = require('eslint-plugin-import-x');
  const { importXResolverCompat } = eslintPluginImportX;
  
  module.exports = {
    settings: {
      // THIS WILL WORK as you have wrapped the previous version of resolvers with the `importXResolverCompat`
      'import-x/resolver-next': [
         importXResolverCompat(require('eslint-import-resolver-node'), nodeResolveOptions),
         importXResolverCompat(require('eslint-import-resolver-webpack'), webpackResolveOptions),
         importXResolverCompat(require('some-custom-resolver'), { option1: true, option2: '' })
      ];
    }
  }

  For custom import resolver developers

  This is the new API design of the resolver interface:

  export interface NewResolver {
    interfaceVersion: 3;
    name?: string; // This will be included in the debug log
    resolve: (modulePath: string, sourceFile: string) => ResolvedResult;
  }
  
  // The `ResultNotFound` (returned when not resolved) is the same, no changes
  export interface ResultNotFound {
    found: false;
    path?: undefined;
  }
  
  // The `ResultFound` (returned resolve result) is also the same, no changes
  export interface ResultFound {
    found: true;
    path: string | null;
  }
  
  export type ResolvedResult = ResultNotFound | ResultFound;

  You will be able to import NewResolver from eslint-plugin-import-x/types.

  The most notable change is that eslint-plugin-import-x no longer passes the third argument (options) to the resolve function.

  We encourage custom resolvers' authors to consume the options outside the actual resolve function implementation. You can export a factory function to accept the options, this factory function will then be called inside the eslint.config.js to get the actual resolver:

  // custom-resolver.js
  exports.createCustomResolver = (options) => {
    // The options are consumed outside the `resolve` function.
    const resolverInstance = new ResolverFactory(options);
  
    return {
      name: 'custom-resolver',
      interfaceVersion: 3,
      resolve(mod, source) {
        const found = resolverInstance.resolve(mod, {});
  
        // Of course, you still have access to the `options` variable here inside
        // the `resolve` function. That's the power of JavaScript Closures~
      }
    }
  };
  
  // eslint.config.js
  const { createCustomResolver } = require('custom-resolver')
  
  module.exports = {
    settings: {
      'import-x/resolver-next': [
         createCustomResolver(options)
      ];
    }
  }

  This allows you to create a reusable resolver instance to improve the performance. With the existing version of the resolver interface, because the options are passed to the resolver function, you will have to create a resolver instance every time the resolve function is called:

  module.exports = {
    interfaceVersion: 2,
    resolve(mod, source) {
      // every time the `resolve` function is called, a new instance is created
      // This is very slow
      const resolverInstance = ResolverFactory.createResolver({});
      const found = resolverInstance.resolve(mod, {});
    },
  };

  With the factory function pattern, you can create a resolver instance beforehand:

  exports.createCustomResolver = (options) => {
    // `enhance-resolve` allows you to create a reusable instance:
    const resolverInstance = ResolverFactory.createResolver({});
    const resolverInstance = enhanceResolve.create({});
  
    // `oxc-resolver` also allows you to create a reusable instance:
    const resolverInstance = new ResolverFactory({});
  
    return {
      name: "custom-resolver",
      interfaceVersion: 3,
      resolve(mod, source) {
        // the same re-usable instance is shared across `resolve` invocations.
        // more performant
        const found = resolverInstance.resolve(mod, {});
      },
    };
  };

Patch Changes

• #184 bc4de89 Thanks @marcalexiei! - fix(no-cycle): improves the type declaration of the rule no-cycle’s maxDepth option

• #184 bc4de89 Thanks @marcalexiei! - fix(first): improves the type declaration of the rule first's option

• #184 bc4de89 Thanks @marcalexiei! - fix(no-unused-modules): improves the type declaration of the rule no-unused-modules’s missingExports option

• #184 bc4de89 Thanks @marcalexiei! - fix(no-deprecated): improve error message when no description is available