`@inline` and `@inlineType` not usable with `@typedef`

[stwlam]

I wasn't sure whether to report this as a bug or feature request since @inline, etc. aren't explicitly marked as supporting @typedef. But since @typedefs are converted to type aliases or interfaces, it seems it should have worked out of the box.

Search terms

inline, expand, typedef

Expected Behavior

The @inline tag may be placed on type aliases and interfaces. When a type is annotated with @inline and the type is referenced, TypeDoc will attempt to inline the referenced type within the other type.

Actual Behavior

The referenced type and type definition itself fall back to any:

Steps to reproduce the bug

/**
 * @typedef HelloProps
 * @inline
 * @property {string} name Name property docs
 */

/**
 * Hello component - HelloProps will be inlined here as
 * if you had written `Hello(props: { name: string })`
 * @param {HelloProps} props
 */
export function hello(props) {
  return "Hello {props.name}!";
}

Moving the placement of @inline to above @typedef or below the @property has it get ignored entirely (perhaps expected).

Environment

• Typedoc version: 0.28.1
• TypeScript version: 5.6.3
• Node.js version: 22.14.0
• OS: Ubuntu 22.04.5

[Gerrit0]

Switching to feature type -- @typedef, despite being converted as a type alias, takes an entirely different code path because it is special and doesn't follow the normal structure that TypeDoc relies on for type aliases. It should be relatively straightforward to add support for @inline.

I'd kind of expect @expand to work already as that tag is used when rendering, at which point TypeDoc has unified both typedef and type aliases into a common reflection structure...

[Gerrit0]

After further review, so far as I can tell there is absolutely no way for TypeDoc to support this with @inline because of a limitation of TypeScript's JSDoc parser. It does not support additional tags within the description of a typedef alias.

TypeDoc respects TypeScript's rules for how to parse typedef comments, and there is no place in which @inline can be placed in the typedef comment where TypeScript considers it to be a part of the typedef comment.

(after typedef -- ends parse of @typedef, so TypeDoc's any was correct)

(after properties -- not a part of the typedef declaration, TS allows multiple typedefs in a single comment)

(before typedef -- not a part of the typedef declaration, ditto)

---

You can, however, use @inlineType HelloProps in the comment for hello to inline the type.