为什么在尝试使用eslint nodejs api时未应用eslint插件？

Question

I want to use eslint api in my node js script. I found this: https://eslint.org/docs/developer-guide/nodejs-api . So I am trying to create CLIEngine, load config and lint something using API.

When I am trying to lint some code using API I am getting error: Definition for rule <ruleName> was not found. .

You can watch code in this repo: https://github.com/sharikovvladislav/eslint-try-api-with-plugins

Here is whole my code:

const CLIEngine = require('eslint').CLIEngine;
const Linter = require('eslint').Linter;
const path = require('path');

const cli = new CLIEngine({
    configPath: path.resolve(process.cwd(), '.eslintrc.json')
});

const linter = new Linter();

const result = linter.verifyAndFix('var foo', cli.getConfigForFile("script.js"));

console.log(result);

In result I get something like this:

 ~/tmp/test-eslint-with-plugins  node script.js
{ fixed: false,
  messages:
   [ { ruleId: 'node/no-extraneous-require',
       message:
        'Definition for rule \'node/no-extraneous-require\' was not found.',
       line: 1,
       column: 1,
       endLine: 1,
       endColumn: 2,
       severity: 2,
       nodeType: null }
  // ....
]
}

I have this in my package dependency:

    "eslint": "^6.1.0",
    "eslint-plugin-node": "^9.1.0"

This is my eslintrc:

{
    "extends": [
        "eslint:recommended",
        "plugin:node/recommended"
    ],
    "rules": {
        "node/exports-style": ["error", "module.exports"],
        "node/file-extension-in-import": ["error", "always"],
        "node/prefer-global/buffer": ["error", "always"],
        "node/prefer-global/console": ["error", "always"],
        "node/prefer-global/process": ["error", "always"],
        "node/prefer-global/url-search-params": ["error", "always"],
        "node/prefer-global/url": ["error", "always"],
        "node/prefer-promises/dns": "error",
        "node/prefer-promises/fs": "error"
    }
}

So I specified some plugins and rules. Looks like everything is correct.

I tried to debug a bit and I realised that CLI is created (looks like) normally. Also, config file parsed correctly. I can see this in config properties:

cli.getConfigForFile("script.js").plugins
>> ["node"]
Object.keys(cli.getConfigForFile("script.js").rules).filter(key => key.startsWith('node'))
>> ["node/exports-style", "node/file-extension-in-import", "node/prefer-global/buffer", "node/prefer-global/console", "node/prefer-global/process", "node/prefer-global/url-search-params", "node/prefer-global/url", "node/prefer-promises/dns", "node/prefer-promises/fs", "node/no-deprecated-api", "node/no-extraneous-require", "node/no-missing-require", "node/no-unpublished-bin", "node/no-unpublished-require", "node/no-unsupported-features/es-builtins", "node/no-unsupported-features/es-syntax", "node/no-unsupported-features/node-builtins", "node/process-exit-as-throw", "node/shebang", "node/no-extraneous-import", "node/no-missing-import", "node/no-unpublished-import"]

Why do I get Definition for rule \\'node/no-extraneous-require\\' was not found. error (and other errors like this)? What I am missing?

Answer 1

Main point is not using Linter/linter at all.

The answer is here: https://github.com/eslint/eslint/issues/12030#issuecomment-516214604

Linter class is designed to work in browsers, so it doesn't depend on any file system. This means that the Linter doesn't find/load any plugins, parsers, and shareable configs. You have to prepare those manually by linter.defineRule method and something like.

Here is full code:

const cli = new CLIEngine({
    configPath: path.resolve(process.cwd(), '.eslintrc.json'),
    // eslint --fix *
    fix: true
});

// run lint & get output for fix
const report = cli.executeOnFiles([path.resolve(process.cwd(), 'test.js')]);

// log about report
console.log('>> report', report);

// write fixed files to fs
CLIEngine.outputFixes(report);

Here is full code about how to fix it in my case (github): https://github.com/sharikovvladislav/eslint-try-api-with-plugins/pull/1