DateInRegionFormatter crashes with any non-default allowed components

[andriichernenko]

The following code crashes with 4.0.10:

let from = DateInRegion() + 2.days
let to = DateInRegion()

let fmt = DateInRegionFormatter()
fmt.allowedComponents = [.day]

try fmt.colloquial(from: from, to: to).colloquial // crash here

The problem seems to be here:

public class DateInRegionFormatter {
    // ...
    public func colloquial(from fDate: DateInRegion, to tDate: DateInRegion) throws -> (colloquial: String, time: String?) {
	guard fDate.region.calendar == tDate.region.calendar else {
		throw DateError.DifferentCalendar
	}
	let cal = fDate.region.calendar
	let cmp = cal.dateComponents(self.allowedComponents, from: fDate.absoluteDate, to: tDate.absoluteDate)
	let isFuture = (fDate > tDate)
	
	if cmp.year != 0 { // this condition is true when cmp.year is nil
		// force unwrapping cmp.year results in crash 
		let colloquial_time = try self.colloquial_time(forUnit: .year, withValue: cmp.year!, date: fDate)
		// ...
	}
	// ...

[malcommac]

Thank you for your report; it's a bug because it try to unwrap and verify a component that is not part of the allowedComponents property.
I've just fixed it in this commit 94682db.
It will be part of the 4.0.11 release.

Just a note:
When you do let from = DateInRegion() + 2.days you are adding 2 days to the current date+time, so unless the current datetime is midnight resulting colloquial string is like "tomorrow" (or yesterday, the difference is less than 1 day).