# eslint-comments/no-unused-disable

disallow unused eslint-disable comments

Since refactoring or a bug fix of upstream, an eslint-disable directive-comment may become unnecessary. In that case, you should remove the garbage as soon as possible since the garbage may cause to overlook ESLint warnings in future.

This rule warns unnecessary eslint-disable directive-comments.

# Rule Details

Examples of 👎 incorrect code for this rule:

/*eslint eslint-comments/no-unused-disable: error, eqeqeq: error, no-undef: error */

var foo = bar() //eslint-disable-line no-undef,eqeqeq

Now loading...

/*eslint eslint-comments/no-unused-disable: error, eqeqeq: error, no-undef: error */
/*globals doSomething */

doSomething() //eslint-disable-line

Now loading...

Examples of 👍 correct code for this rule:

/*eslint eslint-comments/no-unused-disable: error, eqeqeq: error, no-undef: error */

var foo = bar() //eslint-disable-line no-undef

Now loading...

/*eslint eslint-comments/no-unused-disable: error, eqeqeq: error, no-undef: error */
/*globals doSomething */

doSomething()

Now loading...

# Known limitations

This rule might not work fine if the rule wasn't loaded from CLIEngine class because this rule is hacky a bit.

Previously, this rule had depended on a private API of ESLint, but the private API was removed at ESLint 5.0.0 (see eslint/eslint#10140 for details). So this rule is now using two public APIs as an alternative hack.

And it needs an assumption:

The rule was loaded from CLIEngine API.
(I.e., the eslint module was loaded already, but the Linter.prototype.verify method hasn't been called yet.)

# How it works

When the rule is loaded, it searches eslint module from require.cache API and it overrides Linter.prototype.verify method.

The overridden Linter.prototype.verify method does the following steps:

If config.rules["eslint-comments/no-unused-disable"] is not enabled, it calls super.verify and returns the result as is.
Otherwise, it calls super.verify with reportUnusedDisableDirectives option.
It converts the result of super.verify as from reportUnusedDisableDirectives errors to eslint-comments/no-unused-disable errors.
It returns the converted result.

← eslint-comments/no-unlimited-disable eslint-comments/no-unused-enable →