@Test public void testGetRunningContainersExpectingTwoContainers() { String container1 = "TEST_CONTAINER_ID1"; String container2 = "TEST_CONTAINER_ID2"; String imageName1 = "TEST_IMAGE_NAME1"; String imageName2 = "TEST_IMAGE_NAME2"; List<Container> containerIds = new ArrayList<Container>() { { add(getContainer(container1, imageName1)); add(getContainer(container2, imageName2)); } }; // // Arrange // this.mockListCommand(containerIds); // // Act // DockerClient target = new DockerClient(dockerClientStub); target.updateContainerState(); Set<String> result = target.getRunningContainers(); // // Assert // assertTrue(result.contains(container1)); assertTrue(result.contains(container2)); }