How to show abbreviated ago Date in Swift

extension Date {
    private static let relativeFormatter: RelativeDateTimeFormatter = {
        let formatter = RelativeDateTimeFormatter()
        formatter.calendar = Calendar(identifier: .gregorian)
        formatter.calendar?.locale = Locale(identifier: "en_US_POSIX")
        formatter.dateTimeStyle = .numeric
        formatter.unitsStyle = .abbreviated
        return formatter
    }()

    var ago: String {
        guard abs(timeIntervalSinceNow) > 60 else {
            return "Just Now"
        }

        let text = Self.relativeFormatter.localizedString(for: self, relativeTo: Date())
        return text
            .replacingOccurrences(of: "ago", with: "")
            .replacingOccurrences(of: "min", with: "m")
            .replacingOccurrences(of: "hr", with: "h")
            .replacingOccurrences(of: "day", with: "d")
            .replacingOccurrences(of: "wk", with: "w")
            .replacingOccurrences(of: "yr", with: "y")
            .replacingOccurrences(of: " ", with: "")
            .trimmingCharacters(in: .whitespaces)
    }
}

struct Fake {
    static let now = Date()
    static let ago3m = now.addingTimeInterval(-3 * 60)
    static let ago3h = now.addingTimeInterval(-3 * 60 * 60)
    static let ago1d = now.addingTimeInterval(-1 * 24 * 60 * 60)
    static let ago3w = now.addingTimeInterval(-3 * 7 * 24 * 60 * 60)
    static let ago3mo = now.addingTimeInterval(-3 * 32 * 24 * 60 * 60)
    static let ago2y = now.addingTimeInterval(-2 * 366 * 24 * 60 * 60)
}

Fake.now.ago // "Just Now"
Fake.ago3m.ago // "3m"
Fake.ago3h.ago //  "3h"
Fake.ago1d.ago // "1d"
Fake.ago3w.ago // "3w"
Fake.ago3mo.ago // "3mo"
Fake.ago2y.ago // "2y"