idlharness: add iterable members if implicitly iterable

Description

Contributor guide

Tech stack

javascript

Domain

testing

Issue type

feature

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

3

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

half day

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

stale

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

clear

Prerequisites

WebIDL specificationJavaScriptidlharness.js codebase

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

30

Research direction

The issue requires adding @@iterator related methods for interfaces that have an indexed property getter and an integer typed length attribute, as per the WebIDL spec (https://heycam.github.io/webidl/#es iterator). The implementation should be added to the idlharness.js file, specifically around the existing TODO at line 2014 (current line numbers may vary). The issue has been open since 2017 with no recent activity, and there are no linked PRs or assignees. The contributor should first understand the WebIDL spec section, then locate the relevant code in idlharness.js, and implement the missing iterable support. Testing should be added to ensure the feature works correctly.