AddressFormatter in Swift

AddressFormatter.swift

import CoreLocation

struct AddressFormatter {
    private let placemark: Placemarkable

    init(placemark: Placemarkable) {
        self.placemark = placemark
    }

    func formattedAddress() -> String {
        let nameOrAddress = placemark.name ?? placemark.thoroughfare
        var city = placemark.locality
        var state = placemark.administrativeArea
        let zip = placemark.postalCode

        var cityAndState: String?
        if let presentCity = city, presentState = state {
            cityAndState = "\(presentCity), \(presentState)"
            city = nil
            state = nil
        }

        let presentInfo = [nameOrAddress, city, state, cityAndState, zip].flatMap{$0}
        return presentInfo.joinWithSeparator(" ")
    }
}

AddressFormatterTests.swift

import XCTest
import CoreLocation

class AddressFormatterTests: XCTestCase {
    var subject: AddressFormatter!

    func test_WithAName_ReturnJustTheName() {
        let placemark = MockPlacemarkable()
        placemark.name = "St. Gambrinus Beer Shoppe"
        subject = AddressFormatter(placemark: placemark)
        XCTAssertEqual(subject.formattedAddress(), "St. Gambrinus Beer Shoppe")
    }

    func test_WithoutANameButWithAnAddress_ReturnJustTheAddress() {
        let placemark = MockPlacemarkable()
        placemark.thoroughfare = "533 Atlantic Ave"
        subject = AddressFormatter(placemark: placemark)
        XCTAssertEqual(subject.formattedAddress(), "533 Atlantic Ave")
    }

    func test_WithANameAndACity_ReturnBoth() {
        let placemark = MockPlacemarkable()
        placemark.name = "St. Gambrinus Beer Shoppe"
        placemark.locality = "Brooklyn"
        subject = AddressFormatter(placemark: placemark)
        XCTAssertEqual(subject.formattedAddress(), "St. Gambrinus Beer Shoppe Brooklyn")
    }

    func test_WithACityAndState_IncludesThemWithAComma() {
        let placemark = MockPlacemarkable()
        placemark.locality = "Brooklyn"
        placemark.administrativeArea = "NY"
        subject = AddressFormatter(placemark: placemark)
        XCTAssertEqual(subject.formattedAddress(), "Brooklyn, NY")
    }

    func test_WithAStateButNoCity_DoesNotIncludeAComma() {
        let placemark = MockPlacemarkable()
        placemark.administrativeArea = "NY"
        subject = AddressFormatter(placemark: placemark)
        XCTAssertEqual(subject.formattedAddress(), "NY")
    }

    func test_WithAOptionalParameters_IncludesThem() {
        let placemark = MockPlacemarkable()
        placemark.thoroughfare = "533 Atlantic Ave"
        placemark.locality = "Brooklyn"
        placemark.administrativeArea = "NY"
        placemark.postalCode = "11217"
        subject = AddressFormatter(placemark: placemark)
        XCTAssertEqual(subject.formattedAddress(), "533 Atlantic Ave Brooklyn, NY 11217")
    }
}

MockPlacemarkable.swift

import Foundation

@objc class MockPlacemarkable: NSObject, Placemarkable {
    var name: String?
    var thoroughfare: String?
    var administrativeArea: String?
    var locality: String?
    var postalCode: String?
}

@Aghassi thanks for the review!

Comment 1: Good idea pulling the placemark out to a let variable. Fortunately, the code in setup isn't needed. The class is recreated by XCTest for each test, so no pollution would occur.

Comment 2: The first test covers just name, right? But I can definitely add a test that checks both, good point.

Comment 3: I like the idea of abstracting comparisons, but an expected placemark seems too heavy handed. Making the strings, however, be variables could be a good compromise.