org.mockito.exceptions.misusing.UnnecessaryStubbingException Maven / Gradle / Ivy

/*
 * Copyright (c) 2016 Mockito contributors
 * This program is made available under the terms of the MIT License.
 */
package org.mockito.exceptions.misusing;

import org.mockito.exceptions.base.MockitoException;

/**
 * This exception indicates presence of unused stubbings.
 * It is highly recommended to remove unused stubbings to keep the codebase clean.
 * You can opt-out from detecting unused stubbings using {@link org.mockito.junit.MockitoJUnitRunner.Silent} or
 * {@link org.mockito.junit.MockitoRule#silent()} (when you are using Mockito JUnit rules.
 * For more information about detecting unused stubbings, see {@link org.mockito.quality.MockitoHint}.
 * 
 * Unnecessary stubbings are stubbed method calls that were never realized during test execution. Example:
 * 

 * //code under test:
 * ...
 * String result = translator.translate("one")
 * ...
 *
 * //test:
 * ...
 * when(translator.translate("one")).thenReturn("jeden"); // <- stubbing realized during code execution
 * when(translator.translate("two")).thenReturn("dwa"); // <- stubbing never realized
 * ...
 * 

 * Notice that one of the stubbed methods were never realized in the code under test, during test execution.
 * The stray stubbing might be an oversight of the developer, the artifact of copy-paste
 * or the effect not understanding the test/code.
 * Either way, the developer ends up with unnecessary test code.
 * In order to keep the codebase clean & maintainable it is necessary to remove unnecessary code.
 * Otherwise tests are harder to read and reason about.
 * 
 * Mockito JUnit Runner triggers UnnecessaryStubbingException only when none of the test methods use the stubbings.
 * This means that it is ok to put default stubbing in a 'setup' method or in test class constructor.
 * That default stubbing needs to be used at least once by one of the test methods.
 * 
 * To find out more about detecting unused stubbings see {@link org.mockito.quality.MockitoHint}.
 * See javadoc for {@link org.mockito.junit.MockitoJUnitRunner} to find out how Mockito JUnit Runner detects unused stubs.
 * See javadoc for {@link org.mockito.junit.MockitoRule} to understand the behavior or Mockito JUnit Rules.
 */
public class UnnecessaryStubbingException extends MockitoException {
    public UnnecessaryStubbingException(String message) {
        super(message);
    }
}