JavaScript promise optional chaining [closed]

Question

I've wrote a piece of code today that really make me sick about:

if ( account.plan_id ) {
    const featuresToCheck = [];
    for (const vertical of Object.keys(account.account_settings.enabled_features)) {
        for (const feature of Object.keys(account.account_settings.enabled_features[vertical])){
            featuresToCheck.push(`${vertical}.${feature}`);
        }
    }
    planService.filterFeatures(account.plan_id.id,featuresToCheck).then((filtered) => {
        filtered.forEach((feature) => {
            const [ vert , feat] = feature.split('.');
            out.account_settings.enabled_features[vert][feat].is_active = false;
        });
        customFieldsService.getAccountCustomFields(account_id, out)
        .then(function(){
            return cb();
        })
        .fail(cb);
    });
} else {
    customFieldsService.getAccountCustomFields(account_id, out)
    .then(function(){
        return cb();
    })
    .fail(cb);
}

Which could be best practice to handle cases like this? Unfortunately I cannot transform it in async/await.

Answer 1

If the part you don't like it the repetition of calling customFieldsServer.getAccountCustomFields(...) in two separate places, then you can avoid that without using async/await like this by create a common promise variable that each branch of the if/else fills in so after the if/else progress can continue using the common promise:

let p;
if ( account.plan_id ) {
    const featuresToCheck = [];
    for (const vertical of Object.keys(account.account_settings.enabled_features)) {
        for (const feature of Object.keys(account.account_settings.enabled_features[vertical])){
            featuresToCheck.push(`${vertical}.${feature}`);
        }
    }
    p = planService.filterFeatures(account.plan_id.id,featuresToCheck).then((filtered) => {
        filtered.forEach((feature) => {
            const [ vert , feat] = feature.split('.');
            out.account_settings.enabled_features[vert][feat].is_active = false;
        });
    });
} else {
    p = Promise.resolve();
}
p.then(() => {
    customFieldsService.getAccountCustomFields(account_id, out).then(function(){
        return cb();
    }).fail(cb);
});

---

But, this would be simpler if you could use async/await and if your promises were standard-type promises (the .fail() you were using is non-standard):

try {
    if ( account.plan_id ) {
        const featuresToCheck = [];
        for (const vertical of Object.keys(account.account_settings.enabled_features)) {
            for (const feature of Object.keys(account.account_settings.enabled_features[vertical])){
                featuresToCheck.push(`${vertical}.${feature}`);
            }
        }
        let filtered = await planService.filterFeatures(account.plan_id.id,featuresToCheck);
        filtered.forEach((feature) => {
            const [ vert , feat] = feature.split('.');
            out.account_settings.enabled_features[vert][feat].is_active = false;
        });
    }
    await customFieldsService.getAccountCustomFields(account_id, out);
    cb();
} catch(e) {
    cb(e);
}