webdriverio: async errors in executeAsync are not getting caught by Selenium

In my tests, I’m using this pattern when I need to run browser.executeAsync:

const result = browser.executeAsync(function(param, done) {
    setTimeout(function() {
        const result = getResult();
        if (result) {
            done([null, result]);
        } else {
            done(['getResult() failed because...']);
        }
    }, 1000);
});
return checkAsyncResult(result)

function checkAsyncResult(result) {
    if (!result || !Array.isArray(result.value)) {
        throw Error(`Unexpected reponse from executeAsync: ${JSON.stringify(result.value)}`);
    }

    if (result.value[0]) {
        throw result.value[0];
    }

    return result.value[1];
};

It’d be quite nice if webdriverio could do this automatically, and we could standardise on the [(err), res] format for async responses. It’s somewhat related to the idea of making WebElement JSON objects first-class citizens.