require-code-fence-language

Require Markdown fenced code blocks inside TypeDoc comments to declare a language.

Targeted pattern scope

This rule scans TypeDoc block comments for Markdown triple-backtick fences and checks opening fences.

What this rule reports

This rule reports opening code fences that omit a language identifier (for example, ``` instead of ```ts).

Why this rule exists

Language-less fences reduce syntax highlighting quality and readability in generated docs. Explicit language tags produce more consistent docs output.

❌ Incorrect

/**
 * Render value.
 * @example
 * ```
 * renderValue(1);
 * ```
 */
export function renderValue(value: number): string {
    return String(value);
}

✅ Correct

/**
 * Render value.
 * @example
 * ```ts
 * renderValue(1);
 * ```
 */
export function renderValue(value: number): string {
    return String(value);
}

Behavior and migration notes

Autofix adds ts as the default language to missing opening fences.

ESLint flat config example

import typedocPlugin from "eslint-plugin-typedoc";

export default [
    {
        plugins: { typedoc: typedocPlugin },
        rules: {
            "typedoc/require-code-fence-language": "error",
        },
    },
];

When not to use it

Disable when your comments intentionally use language-agnostic fences for non-code prose snippets.

Package documentation

TypeDoc package documentation:

• TypeDoc comments and Markdown support

Further reading

Rule catalog ID: R014

• TypeDoc comments and tags

Adoption resources

• Especially useful when teams embed multi-line examples directly in API comments.