no-extra-type-param-tags

Disallow stale generic tags (@typeParam/@template) that do not map to declared type parameters.

Targeted pattern scope

This rule checks documented generic declarations:

• function declarations and declared functions,
• methods,
• classes,
• interfaces,
• type aliases.

What this rule reports

This rule reports generic documentation tags whose names are not present in the declaration's generic type parameter list.

Why this rule exists

Generic signatures change frequently. Stale generic tags are hard to spot manually and can mislead generated docs.

❌ Incorrect

/**
 * Build a pair.
 * @typeParam TLeft Left type.
 * @typeParam TRight Right type.
 * @typeParam TExtra Stale generic.
 * @param left Left value.
 * @param right Right value.
 * @returns Pair tuple.
 */
export function pair<TLeft, TRight>(left: TLeft, right: TRight): [TLeft, TRight] {
    return [left, right];
}

✅ Correct

/**
 * Build a pair.
 * @typeParam TLeft Left type.
 * @typeParam TRight Right type.
 * @param left Left value.
 * @param right Right value.
 * @returns Pair tuple.
 */
export function pair<TLeft, TRight>(left: TLeft, right: TRight): [TLeft, TRight] {
    return [left, right];
}

Behavior and migration notes

This rule accepts both @typeParam and @template as generic tags, and only validates name mapping.

ESLint flat config example

import typedocPlugin from "eslint-plugin-typedoc";

export default [
    {
        plugins: { typedoc: typedocPlugin },
        rules: {
            "typedoc/no-extra-type-param-tags": "error",
        },
    },
];

When not to use it

Disable this rule during intermediate migrations where docs are intentionally ahead of code changes.

Package documentation

TypeDoc package documentation:

• TypeDoc @typeParam tag

Further reading

Rule catalog ID: R009

• TypeDoc comments and tags

Adoption resources

• Combine with require-type-param-tags for complete and accurate generic docs.