Extending a tuple with an optional member causes an error

[eemeli]

Search terms

tuple, optional, convertType

Expected Behavior

Docs should be generated for valid code.

Actual Behavior

Extending a tuple type that includes an optional member causes TypeDoc to exit with an unexpected error. This might be related to #1439.

Steps to reproduce the bug

Try to generate docs for this:

export function fails<T extends [foo: any, bar?: any]>(a: T): T {
  return a;
}

This causes an error Cannot read property 'name' of undefined to be thrown from here

typedoc/src/lib/converter/types.ts

Line 819 in 0c3b1a0

namedMembers[i].name.text,

due to elements having a length that's one greater than the length of namedMembers.

Minimal reproduction: https://gist.github.com/eemeli/a860c474d8a8a221985aa3fc883baed0

Environment

• Typedoc version: 0.20.10
• TypeScript version: 4.1.3
• Node.js version: 14.9.0
• OS: macOS Mojave 10.14.3

[Gerrit0]

Oh shoot.. this is another instance of #1408. TS does weird things with generic constraints. Fixed in 0.20.11, thanks for the reproduction!