no-unused-vars wrong error when using imported JSDoc definition as @property type.

[ernestostifano]

eslint-plugin-jsdoc/no-undefined-types is correctly added to ESLint configuration.

import {myTypesA} from '../internal/file.js'; // ERROR
import {myTypesB} from '../internal/file.js'; // NO ERROR

/**
* @typedef newType
* @property {myTypesA.someType} someProp - Some prop.
*/

/**
* @param {newType} arg - Arg.
*/
function myFunctionA(arg) {
    return arg;
}

/**
* @param {myTypesB.someType} arg - Arg.
*/
function myFunctionB(arg) {
    return arg;
}

What did you expect to happen?

There should not be an error.
JSDoc definition is correctly imported and used even when the error is present.
The error only appears when imported type is used as a type for a @property tag.
Error does not appear is used in @param tag.

What actually happened? Please include the actual, raw output from ESLint.

/path/to/issue/file.js
  1:9  error  'fiberRegExpTypes' is defined but never used  no-unused-vars

Please see this ESLint issue for more details.

[brettz9]

This is basically a dupe of #99 which I've just renamed and edited slightly to reflect this fact more clearly. See also #178. Closing, but feel free to comment further as needed or add to those issues as needed.

As I have a lot on my plate now, if someone else were up to implementing, my incomplete project at https://github.com/brettz9/es-file-traverse has some code comments which might give ideas for a strategy and tools that could be used.

[brettz9]

Apologies, I think I misread your issue.

[brettz9]

I've reduced the test case to this:

{
      code: `
      import {myTypesA} from '../internal/file.js'; // ERROR
      import {myTypesB} from '../internal/file.js'; // NO ERROR

      /**
      * @typedef newType
      * @property {myTypesA.someType} someProp - Some prop.
      */

      /**
      * @param {newType} arg - Arg.
      */
      function myFunctionA(arg) {
          return arg;
      }

      /**
      * @param {myTypesB.someType} arg - Arg.
      */
      function myFunctionB(arg) {
          return arg;
      }
      export {myFunctionA, myFunctionB};
      `,
      parserOptions: {
        sourceType: 'module',
      },
      rules: {
        'no-unused-vars': ['error'],
      },
    },

...and am indeed getting an error that myTypesA is unused.

(Please note that I have added the second asterisk to the /** block as jsdoc requires it (and therefore so do we. I've also added an export line for myFunctionA, and myFunctionB so they wouldn't get marked as unused as well.)

[brettz9]

The issue seems to be, not with it being on @property vs. @param but due to it not being attached to a regular context like a function and instead to a @typedef comment block not above any function or such context.

The strange thing is that I see that myTypesA is in fact found and added to the line context.markVariableAsUsed(name) within the no-undefined-types rule, but it seems not to be registered with eslint for some reason.

[brettz9]

This looks like it may be related to eslint/eslint#9810 .

[ernestostifano]

@brettz9 thank you for your response and sorry that my report wasn't clear at first sight. I've just added the mandatory second asterisks, it was just a typo.

As far as I know @typedef blocks are not intended to be attached to any other JavaScript context. Indeed, my example is very similar to the @typedef usage example in JSDoc official documentation.

Since your mentioned ESLint issue has been archived, shouldn't we fix this by our own means?

I'm not familiar with your codebase, but if you think that I might be of help in some way, please let me know.

[ernestostifano]

Side note: WebStorm correctly marks myTypesA as used (no error), auto-completion works as intended and even TypeScript generates correct declaration files without complaining. This is just to reinforce the fact that myTypesA seems to be correctly used and that "no error" should be the correct behaviour.