Mocking static methods with Mockito

Question

I\'ve written a factory to produce java.sql.Connection objects:

public class MySQLDatabaseConnectionFactory implements DatabaseConnectionFactory         


        

Answer 1

For those who use JUnit 5, Powermock is not an option. You'll require the following dependencies to successfully mock a static method with just Mockito.

testCompile    group: 'org.mockito', name: 'mockito-core',           version: '3.6.0'
testCompile    group: 'org.mockito', name: 'mockito-junit-jupiter',  version: '3.6.0'
testCompile    group: 'org.mockito', name: 'mockito-inline',         version: '3.6.0'

mockito-junit-jupiter add supports for JUnit 5.

And support for mocking static methods is provided by mockito-inline dependency.

Example:

@Test
void returnUtilTest() {
    assertEquals("foo", UtilClass.staticMethod("foo"));

    try (MockedStatic classMock = mockStatic(UtilClass.class)) {

        classMock.when(() -> UtilClass.staticMethod("foo")).thenReturn("bar");

        assertEquals("bar", UtilClass.staticMethod("foo"));
     }

     assertEquals("foo", UtilClass.staticMethod("foo"));
}

The try-catch block is used to make the static mock remains temporary, so it's mocked only within that scope. But It's not mandatory to use a try-catch block.