Overview

Im trying to create an initialise an object with known keys, however the initial empty object {} that I need breaks my typing.

The problem:

I have a list of value, that I want to use as keys, and I want to initialise an object with those keys. In python i would do something like:

myDict = {key: value for (key, value) in zip(myKeys, [[]]*len(myKeys))}

This should give the myDict the type Record<myKeys, string[]>

In TS, i dont seem to be able to have the same luck, as i need to initialise the object to an empty list before i can populate it with my keys/values. I would rather not need to call it a partial, then coerce it into the correct type.

what ive tried:

I have tried:

    const allPlanFeatures: Partial<Record<ExtensivePlanHandle, string[]>> = {};
    for (const planId of extensivePlanList) {
        const features = getFeaturesForPlan(planHandleToMonthly[planId], is4kEnabled, exportFlow);
        allPlanFeatures[planId] = features;
    }
    return allPlanFeatures as Record<ExtensivePlanHandle, string[]>;

and

 const allPlanFeatures: Partial<Record<ExtensivePlanHandle, string[]>> =
        extensivePlanList.reduce(
            (a, planHandle) => ({
                ...a,
                [planHandle]: getFeaturesForPlan(
                    planHandleToMonthly[planHandle],
                    is4kEnabled,
                    exportFlow
                ),
            }),
            {}
        );
    return allPlanFeatures as Record<ExtensivePlanHandle, string[]>;

These do end up with the desired effect at the end of the day, but I'd rather be able to not have this partially working middle