Cannot disable "typescript is not installed" warning as instructed #1773

Expected behavior

The warning issued states

⚠️ typescript is not installed. jsdoc/no-unnecessary-type-assertion will not work. To disable this warning, you must disable the rule.

If the jsdoc/no-unnecessary-type-assertion rule is not enabled, this warning should not be issued.

Actual behavior

The warning is issued as soon as the package is imported, even if the plugin isn't enabled in the config at all.

ESLint Config

import jsdoc from 'eslint-plugin-jsdoc';

export default [
    {
        // Normally we'd configure eslint-plugin-jsdoc and such in here, but it's not actually necessary to illustrate the bug.
    },
];

Note that you have to make sure that the optional peer dependency on typescript isn't automatically installed. For example, with pnpm, set autoInstallPeers: false in pnpm-workspace.yaml.

ESLint sample

No specific code is necessary, just run eslint.

Environment

• Node version: v24.21.0
• ESLint version v10.10.0
• eslint-plugin-jsdoc version: 64.5.3

Additional notes

PR #1769 fixed one part of #1768, but not this part. It seemed cleanest to file a separate report. 🙂

I suppose you could instead change the warning to state "To disable this warning, install typescript" if you'd rather.