InvoiceControllerUnitTest.java

@RunWith(SpringRunner.class)
@WebMvcTest(InvoiceController.class)
public class InvoiceControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private InvoiceService invoiceService;

    private static final ObjectMapper mapper = new ObjectMapper();

    @Test
    public void testWhenPhoneNumEnteredAndDataExists_thenReturnHttp200() throws Exception {

        final String mockPhoneNumber = "534*******";

        final FileInputStream fileInputStream = new FileInputStream(ResourceUtils.getFile("classpath:response_http200.json"));
        final String staticResponse = StreamUtils.copyToString(fileInputStream, Charset.defaultCharset());

        InvoiceResponse mockInvoiceResponse = mapper.readValue(staticResponse, InvoiceResponse.class);

        when(invoiceService.getInvoiceInfo(mockPhoneNumber))
                .thenReturn(mockInvoiceResponse);

        mockMvc.perform(get("/invoiceQuery/{phoneNumber}", mockPhoneNumber))
                .andExpect(jsonPath("$.statusCode", is("200")));

    }

    @Test
    public void testWhenPhoneNumEnteredAndNoDataFound_thenReturnHttp204() throws Exception {

        final String mockPhoneNumber = "542*******";

        final FileInputStream fileInputStream = new FileInputStream(ResourceUtils.getFile("classpath:response_http204.json"));
        final String staticResponse = StreamUtils.copyToString(fileInputStream, Charset.defaultCharset());

        InvoiceResponse mockInvoiceResponse = mapper.readValue(staticResponse, InvoiceResponse.class);

        when(invoiceService.getInvoiceInfo(mockPhoneNumber))
                .thenReturn(mockInvoiceResponse);

        mockMvc.perform(get("/invoiceQuery/{phoneNumber}", mockPhoneNumber))
                .andExpect(jsonPath("$.statusCode", is("204")));

    }

}