valid-types false positive for type-guard syntax

[Shinigami92]

Expected behavior

Should allow type guards

Working example:

Actual behavior

ESLint Config

{
  "extends": ["plugin:jsdoc/recommended"]
}

ESLint sample

/**
 * String Type-Guard
 *
 * @param {any} value Value
 * @returns {value is string} `true` if value is of type string, otherwise `false`
 */
function isString(value) {
  return typeof value === "string";
}

Environment

• Node version: 14.4.0
• ESLint version 7.1
• eslint-plugin-jsdoc version: 27.0.4

[brettz9]

I believe this is a dupe of jsdoctypeparser/jsdoctypeparser#50 (our dependency for handling type parsing).