ts 5.2 API Change: labeledElementDeclarations can contain undefined

[alex-kinokon]

This isn’t really as much as a bug report as a heads-up. TypeScript 5.2 RC contains a breaking change that affects typedoc:

labeledElementDeclarations May Hold undefined Elements

In order to support a mixture of labeled and unlabeled elements, TypeScript’s API has changed slightly. The labeledElementDeclarations property of TupleType may hold undefined for at each position where an element is unlabeled.

  interface TupleType {
-     labeledElementDeclarations?: readonly (NamedTupleMember | ParameterDeclaration)[];
+     labeledElementDeclarations?: readonly (NamedTupleMember | ParameterDeclaration | undefined)[];
  }

Search terms

labeledElementDeclarations, TypeError: Cannot read properties of undefined (reading 'name')

[WikiRik]

Yes, this happens on the newly released TypeScript 5.2.2. A naive update of two lines in the snippet below

typedoc/src/lib/converter/types.ts

Lines 922 to 932 in 76c918c

	if (type.target.labeledElementDeclarations) {
	const namedDeclarations = type.target.labeledElementDeclarations;
	elements = elements?.map(
	(el, i) =>
	new NamedTupleMember(
	namedDeclarations[i].name.getText(),
	!!namedDeclarations[i].questionToken,
	removeUndefined(el),
	),
	);
	}

to

                 namedDeclarations[i]!.name.getText(), 
                 !!namedDeclarations[i]!.questionToken, 

casues 10 tests to fail