Test driving external dependencies

CurrencyPublisherTest.java

public class CurrencyPublisherTest {

    private SubscriptionRepository subscriptionRepository = mock(SubscriptionRepository.class);
    private EmailService emailService = mock(EmailService.class);
    private CurrencyPublisher publisher = new CurrencyPublisher();
    private CurrencyService currencyService = mock(CurrencyService.class);
    private GeolocationService geolocationService = mock(GeolocationService.class);

    @Test
    public void shouldPublishCurrency() throws Exception {
        Subscription subscription = TestDataFactory.randomSubscription();
        String location = TestDataFactory.randomCountry();
        String currency = TestDataFactory.randomCurrency();
        double exchangeRate = subscription.getLowLimit() * 0.9;

        when(subscriptionRepository.findPendingSubscriptions()).thenReturn(Arrays.asList(subscription));

        when(geolocationService.getCountryByIp(subscription.getIpAddress())).thenReturn(location);

        when(currencyService.getCurrency(location)).thenReturn(currency);
        when(currencyService.getExchangeRateFromUSD(currency)).thenReturn(exchangeRate);

        publisher.runPeriodically();

        verify(emailService).publishCurrencyAlert(subscription, currency, exchangeRate);
    }

    @Before
    public void setupPublisher() {
        publisher.setSubscriptionRepository(subscriptionRepository);
        publisher.setGeolocationService(geolocationService);
        publisher.setCurrencyService(currencyService);
        publisher.setEmailService(emailService);
    }
}

GeolocationServiceLiveTest.java

public class GeolocationServiceLiveTest {

    @Test
    public void shouldFindLocation() throws Exception {
        GeolocationService wsClient = new GeolocationServiceWsClient("http://www.webservicex.net/geoipservice.asmx");
        assertThat(wsClient.getCountryByIp("80.203.105.247")).isEqualTo("Norway");
    }

}

GeolocationServiceStub.java

public class GeolocationServiceStub extends HttpServlet {

    private Map<String,String> locations = new HashMap<String, String>();

    public void addLocation(String ipAddress, String country) {
        locations.put(ipAddress, country);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        try {
            String ipAddress = $(req.getReader()).xpath("/Envelope/Body/GetGeoIP/IPAddress").text();
            String location = locations.get(ipAddress);
            createResponse(location).write(resp.getOutputStream());
        } catch (Exception e) {
            throw new RuntimeException("Exception at server " + e);
        }
    }
}

GeolocationServiceStubHttpTest.java

public class GeolocationServiceStubHttpTest {

    @Test
    public void shouldAnswerCountry() throws Exception {
        GeolocationServiceStub stub = new GeolocationServiceStub();
        stub.addLocation("80.203.105.247", "Norway");

        Server server = new Server(0);
        ServletContextHandler context = new ServletContextHandler();
        context.addServlet(new ServletHolder(stub), "/GeoService");
        server.setHandler(context);
        server.start();

        String url = "http://localhost:" + server.getConnectors()[0].getLocalPort();

        GeolocationService wsClient = new GeolocationServiceWsClient(url + "/GeoService");
        String location = wsClient.getCountryByIp("80.203.105.247");

        assertThat(location).isEqualTo("Norway");
    }
}

GeolocationServiceWsClient.java

public class GeolocationServiceWsClient implements GeolocationService {

    private Validator validator;
    private UrlSoapEndpoint endpoint;

    public GeolocationServiceWsClient(String url) throws Exception {
        this.endpoint = new UrlSoapEndpoint(url);
        validator = createValidator();
    }

    @Override
    public String getCountryByIp(String ipAddress) throws Exception {
        Element request = createGeoIpRequest(ipAddress);
        Document soapRequest = createSoapEnvelope(request);
        validateXml(soapRequest);
        Document soapResponse = endpoint.postRequest(getSOAPAction(), soapRequest);
        validateXml(soapResponse);
        return parseGeoIpResponse(soapResponse);
    }

    private void validateXml(Document soapMessage) throws Exception {
        validator.validate(toXmlSource(soapMessage));
    }

    protected Validator createValidator() throws SAXException {
        SchemaFactory schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
        Schema schema = schemaFactory.newSchema(new Source[] {
              new StreamSource(getClass().getResource("/geoipservice.xsd").toExternalForm()),
              new StreamSource(getClass().getResource("/soap.xsd").toExternalForm()),
        });
        return schema.newValidator();
    }

    private Document createSoapEnvelope(Element request) throws Exception {
        return $("S:Envelope",
                $("S:Body", request)).document();
    }

    private Element createGeoIpRequest(String ipAddress) throws Exception {
        return $("wsx:GetGeoIP", $("wsx:IPAddress", ipAddress)).get(0);
    }

    private String parseGeoIpResponse(Element response) {
        // TODO
        return null;
    }

    private Source toXmlSource(Document document) throws Exception {
        return new StreamSource(new StringReader($(document).toString()));
    }
}

UrlSoapEndpoint.java

public class UrlSoapEndpoint {

    private final String url;

    public UrlSoapEndpoint(String url) {
        this.url = url;
    }

    public Document postRequest(String soapAction, Document soapRequest) throws Exception {
        URL httpUrl = new URL(url);
        HttpURLConnection connection = (HttpURLConnection) httpUrl.openConnection();
        connection.setDoInput(true);
        connection.setDoOutput(true);
        connection.addRequestProperty("SOAPAction", soapAction);
        connection.addRequestProperty("Content-Type", "text/xml");
        $(soapRequest).write(connection.getOutputStream());

        int responseCode = connection.getResponseCode();
        if (responseCode != 200) {
            throw new RuntimeException("Something went terribly wrong: " + connection.getResponseMessage());
        }
        return $(connection.getInputStream()).document();
    }
}