FixtureAsserts.java

package org.multibit.mbm.test;

import com.google.common.base.Charsets;
import com.google.common.io.Resources;
import com.theoryinpractise.halbuilder.spi.Resource;
import com.yammer.dropwizard.json.Json;
import junit.framework.Assert;
import org.codehaus.jackson.JsonNode;
import org.multibit.mbm.api.hal.HalMediaType;

import java.io.IOException;
import java.util.Arrays;

import static junit.framework.Assert.assertTrue;

/**
 * <p>Fixture assertions to provide the following to application:</p>
 * <ul>
 * <li>Support methods to simplify common test patterns</li>
 * </ul>
 *
 * @since 0.0.1
 */
public class FixtureAsserts {

  private static final Json JSON = new Json();

  /**
   * Validates the fixture JSON and provides a minified String for comparison
   *
   * @param fixtureClasspath The classpath (can be in other JARs)
   *
   * @return The contents as parsed by JSON
   *
   * @throws IOException If something goes wrong
   */
  public static String jsonFixture(String fixtureClasspath) throws IOException {
    return JSON.writeValueAsString(JSON.readValue(fixture(fixtureClasspath), JsonNode.class));
  }

  /**
   * @param fixtureClasspath The classpath (can be in other JARs)
   *
   * @return A contents as a UTF8 string
   *
   * @throws IOException If something goes wrong
   */
  public static String fixture(String fixtureClasspath) throws IOException {
    return Resources.toString(FixtureAsserts.class.getResource(fixtureClasspath), Charsets.UTF_8).trim();
  }

  /**
   * Takes a String and compares it to a JSON fixture (
   *
   * @param reason           The reason (e.g. "a Customer can be marshalled to JSON")
   * @param representation   The simple string representation
   * @param fixtureClasspath The classpath reference to the resource (e.g. "fixtures/example.json")
   *
   * @throws java.io.IOException If something goes wrong
   */
  public static void assertStringMatchesJsonFixture(String reason, String representation, String fixtureClasspath) throws IOException {

    Assert.assertEquals(reason,
      jsonFixture(fixtureClasspath),
      representation
    );
  }

  /**
   * Takes a String and compares it to a normalised String fixture
   *
   * @param reason           The reason (e.g. "a Customer can be marshalled to JSON")
   * @param representation   The simple string representation
   * @param fixtureClasspath The classpath reference to the resource (e.g. "/fixtures/example.json")
   *
   * @throws java.io.IOException If something goes wrong
   */
  public static void assertStringMatchesStringFixture(String reason, String representation, String fixtureClasspath) throws IOException {

    Assert.assertEquals(reason,
      fixture(fixtureClasspath),
      representation
    );
  }

  /**
   * Renders a HAL resource as JSON and compares it to a normalised JSON fixture
   *
   * @param reason           The reason (e.g. "a Customer can be marshalled to JSON")
   * @param representation   The HAL representation
   * @param fixtureClasspath The classpath reference to the resource (e.g. "fixtures/example.json")
   *
   * @throws java.io.IOException If something goes wrong
   */
  public static void assertRepresentationMatchesJsonFixture(String reason, Resource representation, String fixtureClasspath) throws IOException {

    Assert.assertEquals(reason,
      jsonFixture(fixtureClasspath),
      representation.renderContent(HalMediaType.APPLICATION_HAL_JSON)
    );
  }

  /**
   * Renders a HAL representation as JSON and compares it to the expected fixture
   *
   * @param reason           The reason (e.g. "a Customer can be marshalled to JSON")
   * @param representation   The HAL representation
   * @param fixtureClasspath The classpath reference to the resource (e.g. "fixtures/example.xml")
   *
   * @throws java.io.IOException If something goes wrong
   */
  public static void assertRepresentationMatchesXmlFixture(String reason, Resource representation, String fixtureClasspath) throws IOException {
    Assert.assertEquals(reason,
      fixture(fixtureClasspath),
      representation.renderContent(HalMediaType.APPLICATION_HAL_XML)
    );
  }

  /**
   * Compares the given byte[] with that read from the expected fixture
   *
   * @param reason           The reason (e.g. "a correct swatch has been generated")
   * @param representation   The byte[] to test
   * @param fixtureClasspath The classpath reference to the resource (e.g. "fixtures/example.png")
   *
   * @throws java.io.IOException If something goes wrong
   */
  public static void assertRepresentationMatchesBinaryFixture(String reason, byte[] representation, String fixtureClasspath) throws IOException {
    assertTrue(reason, Arrays.equals(representation, BinaryFixtureHelpers.fixture(fixtureClasspath)));
  }

}