eslint-lockdown

generate an .eslintrc against a legacy codebase

usage

$ npm i -g eslint-lockdown
$ eslint-lockdown

eslint-lockdown will generate an .eslintrc to utilize eslint against a legacy codebase. It reads in your (optional) current .eslintrc file and generates a new .eslintrc with failing rules marked as warn. This allows you to "put a stake in the ground" to prevent your code getting worse, utilizing eslint as part of your build process without halting development.

By default, eslint-lockdown will overwrite the .eslintrc file. To preview the results without overwriting:

$ eslint-lockdown --debug

example

This snippet, foo.js:

module.exports = function() {
    var unused = true;
    console.log("foobar");
}

violates many eslint:recommended rules:

$ eslint foo.js

/foo/bar/foo.js
  1:1  error  "module" is not defined             no-undef
  2:9  error  "unused" is defined but never used  no-unused-vars
  3:5  error  Unexpected console statement        no-console
  3:5  error  "console" is not defined            no-undef

✖ 4 problems (4 errors, 0 warnings)

Running eslint-lockdown, we would generate an .eslintrc file to make eslint pass:

{
    "extends": "eslint:recommended",
    "rules": {
        "no-undef": [ 1 ],
        "no-unused-vars": [ 1 ],
        "no-console": [ 1 ]
    }
}

After generating the new file, eslint will pass with warnings:

$ eslint .

/Users/john/mysrc/weisjohn/scratch/eslint_lockdown/index.js
  1:1  warning  "module" is not defined             no-undef
  2:9  warning  "unused" is defined but never used  no-unused-vars
  3:5  warning  Unexpected console statement        no-console
  3:5  warning  "console" is not defined            no-undef

✖ 4 problems (0 errors, 4 warnings)

library

If you want to further wrangle the configuration, you can use eslint-lockdown as a node library:

var lockdown = require('eslint-lockdown');

lockdown(__dirname, function(err, config) {
    if (err) return console.error(err);
    console.log(config);
});