Class AbstractAssert

src/main/java/org/assertj/core/api/AbstractAssert.java:45–524

Base class for all assertions. @param the "self" type of this assertion class. Please read " Emulating 'self types' using Java Generics to simplify fluent API implementation " for more details. @param the type of t

 * @author Nicolas François
 */
public abstract class AbstractAssert<S extends AbstractAssert<S, A>, A> implements Assert<S, A> {

  @VisibleForTesting
  Objects objects = Objects.instance();

  @VisibleForTesting
  Conditions conditions = Conditions.instance();

  @VisibleForTesting
  protected final WritableAssertionInfo info;

  // visibility is protected to allow us write custom assertions that need access to actual
  @VisibleForTesting
  protected final A actual;
  protected final S myself;

  // we prefer not to use Class<? extends S> selfType because it would force inherited
  // constructor to cast with a compiler warning
  // let's keep compiler warning internal (when we can) and not expose them to our end users.
  @SuppressWarnings("unchecked")
  protected AbstractAssert(A actual, Class<?> selfType) {
	myself = (S) selfType.cast(this);
	this.actual = actual;
	info = new WritableAssertionInfo();
  }

  /**
   * Exposes the {@link WritableAssertionInfo} used in the current assertion for better extensibility.</br> When writing
   * your own assertion class, you can use the returned {@link WritableAssertionInfo} to change the error message and
   * still keep the description set by the assertion user.
   * 
   * @return the {@link WritableAssertionInfo} used in the current assertion
   */
  protected WritableAssertionInfo getWritableAssertionInfo() {
	return info;
  }

  /**
   * Utility method to ease writing custom assertions classes, you can use format specifiers in error message, they
   * will be replaced by the given arguments.
   * <p>
   * Moreover, this method honors any description ({@link #as(String, Object...)} or overridden error message defined by
   * the user ( {@link #overridingErrorMessage(String, Object...)}.
   * <p>
   * Example :
   * 
   * <pre><code class='java'>
   * public TolkienCharacterAssert hasName(String name) {
   *   // check that actual TolkienCharacter we want to make assertions on is not null.
   *   isNotNull();
   * 
   *   // check condition
   *   if (!actual.getName().equals(name)) {
   *     failWithMessage(&quot;Expected character's name to be &lt;%s&gt; but was &lt;%s&gt;&quot;, name, actual.getName());
   *   }
   * 
   *   // return the current assertion for method chaining
   *   return this;