Inheritance description of properties missing generic type

[DerGernTod]

Search terms

inherit, properties, typescript helpers

Expected Behavior

The link to inherited properties of interfaces with generics should be created properly for interfaces like Partial<Foo>.

Actual Behavior

The inheritance description is created without the generic type, like Partial.propertyOfFoo instead of Partial<Foo>.propertyOfFoo, resulting in a missing link to the generic type.

Steps to reproduce the bug

1. Create typedoc for the following code:

/**
 * Some foo interface
 */
export interface Foo {
    hello: string;
    world: number;
}

/**
 * Some bar interface
 */
export interface Bar extends Partial<Foo> {
    baz: boolean;
}

2. Check the documentation of Bar.hello

You can see that the hierarchy view properly shows Partial<Foo> including the link to Foo, but when rendering the inherited properties, it just says Partial.hello. You can clone my reproducer for simplicity.

Environment

• Typedoc version: 0.28.7
• TypeScript version: 5.8.3
• Node.js version: 22.12.0
• OS: Windows 11

[Gerrit0]

This is because of

typedoc/src/lib/converter/plugins/ImplementsPlugin.ts

Lines 113 to 123 in f60f0a4

	const extendedTypes = filterMap(
	reflection.extendedTypes ?? [],
	(type) => {
	return type instanceof ReferenceType &&
	type.reflection instanceof DeclarationReflection
	? (type as ReferenceType & {
	reflection: DeclarationReflection;
	})
	: void 0;
	},
	);

.

TypeDoc considers inheritance parent-by-parent, which means that it does not consider parents wrapped in some generic type.

Doing so member-by-member is probably a better way of doing this when possible, but needs to be done carefully to ensure the wrong member isn't linked by mistake, e.g.

type Tricky<T> = Omit<T, "x"> & { x: number }

interface Foo {
  x: string
}

interface Bar extends Tricky<Foo> {
  // Bar.x should *not* be linked to Foo.x
}