Class Mockito

mockito-core/src/main/java/org/mockito/Mockito.java:1806–3895

The Mockito library enables mock creation, verification and stubbing. This javadoc content is also available on the https://site.mockito.org/ web page. All documentation

 * </code></pre>
 */
@CheckReturnValue
@SuppressWarnings("unchecked")
public class Mockito extends ArgumentMatchers {

    static final MockitoCore MOCKITO_CORE = new MockitoCore();

    /**
     * The default <code>Answer</code> of every mock <b>if</b> the mock was not stubbed.
     *
     * Typically, it just returns some empty value.
     * <p>
     * {@link Answer} can be used to define the return values of un-stubbed invocations.
     * <p>
     * This implementation first tries the global configuration and if there is no global configuration then
     * it will use a default answer that returns zeros, empty collections, nulls, etc.
     */
    public static final Answer<Object> RETURNS_DEFAULTS = Answers.RETURNS_DEFAULTS;

    /**
     * Optional <code>Answer</code> to be used with {@link Mockito#mock(Class, Answer)}.
     * <p>
     * {@link Answer} can be used to define the return values of un-stubbed invocations.
     * <p>
     * This implementation can be helpful when working with legacy code.
     * Un-stubbed methods often return null. If your code uses the object returned by an un-stubbed call,
     * you get a NullPointerException.
     * This implementation of Answer <b>returns SmartNull instead of null</b>.
     * <code>SmartNull</code> gives nicer exception messages than NPEs, because it points out the
     * line where the un-stubbed method was called. You just click on the stack trace.
     * <p>
     * <code>ReturnsSmartNulls</code> first tries to return ordinary values (zeros, empty collections, empty string, etc.)
     * then it tries to return SmartNull. If the return type is final then plain <code>null</code> is returned.
     * <p>
     * Example:
     * <pre class="code"><code class="java">
     *   Foo mock = mock(Foo.class, RETURNS_SMART_NULLS);
     *
     *   //calling un-stubbed method here:
     *   Stuff stuff = mock.getStuff();
     *
     *   //using object returned by un-stubbed call:
     *   stuff.doSomething();
     *
     *   //Above doesn't yield NullPointerException this time!
     *   //Instead, SmartNullPointerException is thrown.
     *   //Exception's cause links to un-stubbed <i>mock.getStuff()</i> - just click on the stack trace.
     * </code></pre>
     */
    public static final Answer<Object> RETURNS_SMART_NULLS = Answers.RETURNS_SMART_NULLS;

    /**
     * Optional <code>Answer</code> to be used with {@link Mockito#mock(Class, Answer)}
     * <p>
     * {@link Answer} can be used to define the return values of un-stubbed invocations.
     * <p>
     * This implementation can be helpful when working with legacy code.
     * <p>
     * ReturnsMocks first tries to return ordinary values (zeros, empty collections, empty string, etc.)