bug#26001: js-mode: JSX indentation after fat-arrow attribute

[Dražen]

As mentioned in https://github.com/mooz/js2-mode/issues/389#issuecomment-271869380 , there seems to be a bug in the way js-mode (at least the folks there pointed me at js-mode) indents JSX _javascript_.

When I'm doing a map with JSX syntax I'm getting:

render() {
    const messages = this.state.messages.map(
        message => <Message key={message.id}
        text={message.text}
        mine={message.mine} />
    );
    return messages;
}

I'd ideally expect something like:

render() {
    const messages = this.state.messages.map(
        message => <Message key={message.id}
                            text={message.text}
                            mine={message.mine} />
    );
    return messages;
}

It's even odder when I try to leave the argument to the arrow function in the line above:

render() {
    const messages = this.state.messages.map(message =>
                                             <Message key={message.timestamp}
                                             text={message.text}
                                             mine={message.mine} />
                                            );
    return messages;
}

For this second case, I'd hope to get:

render() {
    const messages = this.state.messages.map(message =>
        <Message key={message.timestamp}
                 text={message.text}
                 mine={message.mine} />
    );
    return messages;
}

(I get such results if I wrap the return _expression_ in parentheses)