'Test Fails with "when() requires an argument which has to be 'a method call on a mock' " error on maven project(no frameworks used)
Hi I am trying to mock an insertion in my database and run it for a test. The test is failing with and error "when() requires an argument which has to be 'a method call on a mock'." I am new to this and i need a little help with it.
I am not using any framework
Editing the test code
SaveServlet.java
package com.consentServlets;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/SaveServlet")
public class SaveServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out=response.getWriter();
//Getting the attributes from the UI
String first_Name = request.getParameter("fname");
String last_Name = request.getParameter("lname");
String gender = request.getParameter("gender");
String age = request.getParameter("age");
String dob = request.getParameter("dob");
//Setting the objects to insert the achieved attributes to corresponding the columns of the table
patient addPatient = new patient();
addPatient.setLastName(last_Name);
addPatient.setFirstName(first_Name);
addPatient.setGender(gender);
addPatient.setAge(age);
addPatient.setDoB(dob);
out.print(" <link rel=\"stylesheet\" href=\"https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.css\">");
//calling the save function from the patientDao class to execute the query
int status=patientDao.save(addPatient);
if(status>0){
out.print("<p>Patient Record saved successfully!</p>");
request.getRequestDispatcher("index.html").include(request, response);
}else{
out.println("Sorry! unable to save record");
}
out.close();
}
}
patient.java
package com.consentServlets;
import java.util.List;
//creating objects for patient class which will help to store the patient details
public class patient {
private int id;
private String first_Name,last_Name,gender,age,dob;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getFirstName() {
return first_Name;
}
public void setFirstName(String first_Name) {
this.first_Name = first_Name;
}
public String getLastName() {
return last_Name;
}
public void setLastName(String last_Name) {
this.last_Name = last_Name;
}
public String getGender() {
return gender;
}
public void setGender(String Gender) {
this.gender = Gender;
}
public String getAge() {
return age;
}
public void setAge(String Age) {
this.age = Age;
}
public String getDoB() {
return dob;
}
public void setDoB(String DOB) {
this.dob = DOB;
}
}
patientDao.java
package com.consentServlets;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
public class patientDao {
//establishing the connection with the database
public Connection getConnection(){
Connection con=null;
try{
Class.forName("com.mysql.jdbc.Driver");
con=DriverManager.getConnection("jdbc:mysql://localhost:3306/consent_share","root","");
}catch(Exception e){System.out.println(e);}
return con;
}
public static int save(patient addPatient){
int status = 0;
//Inserting patient details from UI to Database
try{
Connection con = new patientDao().getConnection();
PreparedStatement ps = con.prepareStatement(
"insert into patient(last_name,first_name,gender,age,dob) values (?,?,?,?,?)");
ps.setString(1,addPatient.getLastName());
ps.setString(2,addPatient.getFirstName());
ps.setString(3,addPatient.getGender());
ps.setString(4,addPatient.getAge());
ps.setString(5,addPatient.getDoB());
status = ps.executeUpdate();
con.close();
}catch(Exception ex){ex.printStackTrace();}
return status;
}
public static patient getPatientbyId(int id){
patient getPatient = new patient();
//selecting a patient record by matching the patient_ID
try{
Connection con = new patientDao().getConnection();
PreparedStatement ps = con.prepareStatement("select * from patient where patient_id=?");
ps.setInt(1,id);
ResultSet rs = ps.executeQuery();
if(rs.next()){
getPatient.setId(rs.getInt(1));
getPatient.setLastName(rs.getString(2));
getPatient.setFirstName(rs.getString(3));
getPatient.setGender(rs.getString(4));
getPatient.setAge(rs.getString(5));
getPatient.setDoB(rs.getString(6));
}
con.close();
}catch(Exception ex){ex.printStackTrace();}
return getPatient;
}
// Fetching all the records from table
public static List<patient> getAllPatients(){
List<patient> list = new ArrayList<patient>();
try{
Connection con = new patientDao().getConnection();
PreparedStatement ps = con.prepareStatement("select * from patient");
ResultSet rs = ps.executeQuery();
while(rs.next()){
patient getAllPatients=new patient();
getAllPatients.setId(rs.getInt(1));
getAllPatients.setFirstName(rs.getString(3));
getAllPatients.setLastName(rs.getString(2));
getAllPatients.setGender(rs.getString(4));
getAllPatients.setAge(rs.getString(5));
getAllPatients.setDoB(rs.getString(6));
list.add(getAllPatients);
}
con.close();
}catch(Exception e){e.printStackTrace();}
return list;
}
}
patientTest.java
package com.test;
import static org.junit.Assert.assertEquals;
import java.sql.Connection;
import java.sql.PreparedStatement;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Matchers;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.junit.MockitoJUnitRunner;
import com.consentServlets.patient;
import com.consentServlets.patientDao;
@RunWith(MockitoJUnitRunner.class)
public class patientTest{
@Mock
Connection mockCom;
@Mock
PreparedStatement mockSt;
@InjectMocks
patientDao mockPatDao;
@Test
public void testPatientServlet() throws Exception {
HttpServletRequest request = Mockito.mock(HttpServletRequest.class);
HttpServletResponse response = Mockito.mock(HttpServletResponse.class);
/*
* Mockito.when(request.getParameter("fname")).thenReturn("Rahul");
* Mockito.when(request.getParameter("lname")).thenReturn("Sen");
* Mockito.when(request.getParameter("gender")).thenReturn("Male");
* Mockito.when(request.getParameter("age")).thenReturn("20");
* Mockito.when(request.getParameter("dob")).thenReturn("1996-07-24");
*/
patient patientSave = new patient();
patientSave.setLastName("Rahul");
patientSave.setFirstName("Sen");
patientSave.setGender("Male");
patientSave.setAge("20");
patientSave.setDoB("1996-07-24");
//String query = "";
Mockito.when(new patientDao().getConnection()).thenReturn(mockCom);
Mockito.when(mockCom.prepareStatement(Matchers.anyString())).thenReturn(mockSt);
Mockito.when(mockSt.executeUpdate()).thenReturn(1);
String URI = "/SaveServlet";
//int status=patientDao.save(patientSave);
int actualStatus= mockPatDao.save(patientSave);
int expectedStatus = 1;
//Mockito.when(insert.save(patientSave)).thenReturn(1);
assertEquals(expectedStatus,actualStatus);
}
}
STACKTRACE
org.mockito.exceptions.misusing.MissingMethodInvocationException:
when() requires an argument which has to be 'a method call on a mock'. For example: when(mock.getArticles()).thenReturn(articles);
Also, this error might show up because: 1. you stub either of: final/private/equals()/hashCode() methods. Those methods cannot be stubbed/verified. Mocking methods declared on non-public parent classes is not supported. 2. inside when() you don't call method on mock but on some other object.
at com.test.patientTest.testPatientServlet(patientTest.java:62)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.mockito.internal.runners.DefaultInternalRunner$1$1.evaluate(DefaultInternalRunner.java:46)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:77)
at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:83)
at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39)
at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:89)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)
Solution 1:[1]
In the exception message it says:
inside when() you don't call method on mock but on some other object.
And in your code you have:
patientDao insert = new patientDao();
...
Mockito.when(insert.save(patientSave)).thenReturn(status);
I'm not really sure what you wanted to achieve with that second line but it causes the error and is useless - you should remove it.
Actually the whole test is unclear to me.
If I understand correctly, insert is meant to be the tested object so no point in mocking it, you have to work on an actual object.
Solution 2:[2]
As the stacktrace says when can only be used with mocked objects.
when() requires an argument which has to be 'a method call on a mock'.
While following code has a usage of when where the object is not mocked.
patientDao insert = new patientDao();
Mockito.when(insert.save(patientSave)).thenReturn(status);
You need to mock the remove insert object ORMockito.when(insert.save(patientSave)).thenReturn(status); as it is not needed.
Solution 3:[3]
When you @InjectMocks, Mockito doesn't create a mock. It creates an actual instance, hence the error:
when() requires an argument which has to be 'a method call on a mock'.
Now the error makes sense. This means when() fails because your class is not a mock but an actual instance.
You can solve this by putting @Spy on top of your @InjectMocks annotation.
I found this out from this article: https://mkyong.com/spring-boot/mockito-when-requires-an-argument-which-has-to-be-a-method-call-on-a-mock/
Solution 4:[4]
If you use KOIN, include in the gradle's dependencies:
dependencies {
...
testImplementation "org.koin:koin-test:2.0.0"
}
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | |
| Solution 2 | |
| Solution 3 | Mike Cheel |
| Solution 4 | J. Soares |