Should I unit test these method if so, how?

[must Janik]

I've built ToDoApp. I want to test my controller. I've got methods like:

 public boolean createUser(String username, String password) throws SQLException {
    return userStorage.createUser(new User(username, password));
}
public List<Task> getTasks() throws SQLException {
    return taskStorage.getTasks(connectedUser);
}

I've tried to test them with mocking storage. I've made something like this:

package controller;

import model.Task;
import model.User;
import org.junit.Before;
import org.junit.Test;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
import repository.TaskInterface;
import repository.UserInterface;

import static org.junit.Assert.assertEquals;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;


import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class ToDoEngineTest {

    @Mock
    TaskInterface taskStorageMock;
    @Mock
    UserInterface userStorageMock;
    ToDoEngine toDoEngine;


    @Before
    public void setup() {
        MockitoAnnotations.initMocks(this);
        toDoEngine = new ToDoEngine(userStorageMock, taskStorageMock);
    }

    @Test
    public void createUser() throws SQLException {
        User user = new User("admin", "123");
        toDoEngine.createUser("admin", "123");
        verify(userStorageMock).createUser(user);
    }

    @Test
    public void getTasks() throws SQLException {
        List<Task> tasks = new ArrayList<Task>();
        User user = new User("admin","123");
        Task task = new Task("wash");
        tasks.add(task);
        when(taskStorageMock.getTasks(user)).thenReturn(tasks);

        List<Task> actual = toDoEngine.getTasks();
        List<Task> expected = taskStorageMock.getTasks(user);

        assertEquals(expected,actual);

    }

}

For createUser I've got error like this:

Argument(s) are different! Wanted:
userStorageMock.createUser(
    model.User@a87f8ec
);
-> at controller.ToDoEngineTest.createUser(ToDoEngineTest.java:45)
Actual invocation has different arguments:
userStorageMock.createUser(
    model.User@5443d039
);
-> at controller.ToDoEngine.createUser(ToDoEngine.java:34)

Comparison Failure:  <Click to see difference>

Argument(s) are different! Wanted:
userStorageMock.createUser(
    model.User@a87f8ec
);
-> at controller.ToDoEngineTest.createUser(ToDoEngineTest.java:45)
Actual invocation has different arguments:
userStorageMock.createUser(
    model.User@5443d039
);
-> at controller.ToDoEngine.createUser(ToDoEngine.java:34)

	at controller.ToDoEngineTest.createUser(ToDoEngineTest.java:45)

and for getTasks:

java.lang.AssertionError: 
Expected :[Task: wash]
Actual   :[]
 <Click to see difference>


	at org.junit.Assert.fail(Assert.java:88)
	at org.junit.Assert.failNotEquals(Assert.java:834)
	at org.junit.Assert.assertEquals(Assert.java:118)
	at org.junit.Assert.assertEquals(Assert.java:144)
	at controller.ToDoEngineTest.getTasks(ToDoEngineTest.java:54)

Should I test these methods? If so, how should I improve my actual tests.

[Jeanne Boyarsky]

Does the User object have an equals method defined? If not, Mockito wouldn't see the objects as equal and would behave as you described.

[must Janik]

What do you mean? I do not understand. Ye, objects are not equaled as we see on stacktrace, but how can I deal with it.

[Jeanne Boyarsky]

I'm saying you should write equals and hash code methods for this object.

[must Janik]

I generated these method. What should I do know?

package model;

import java.util.Objects;

public class User {
    private String name;
    private String password;
    private int ID;

    public User(String name, String password) {
        this.name = name;
        this.password = password;
    }

    public int getID() {
        return ID;
    }

    public void setID(int ID) {
        this.ID = ID;
    }

    public String getName() {
        return name;
    }

    public String getPassword() {
        return password;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        User user = (User) o;
        return ID == user.ID &&
                Objects.equals(name, user.name) &&
                Objects.equals(password, user.password);
    }

    @Override
    public int hashCode() {
        return Objects.hash(name, password, ID);
    }
}

[Jeanne Boyarsky]

Consider adding a toString method to print the username (not the password) to get clearer error messages.

Then run your test again. What is the output?

[must Janik]

Well..Test passed. I don't know what `equal` and hashCode` changed...

[Jeanne Boyarsky]

I do . Mockito uses the Hamcrest matchers. When you say which objects you expect to pass in as parameters, it calls equals() on the object ot determine if they are equivalent.

Before, you were using Object equals() implementation. Which checked if they were the same object. Since they weren't, Mockito didn't recognize them as being the same. Once you added the equals() implementation, Mockito saw them as the same and the tests behaved as you expected.

[must Janik]

Well... Thanks. What about the getTasks method? What should I change?

[must Janik]

Once again, to be clear:

 @Test
    public void createUser() throws SQLException {
        User user = new User("admin", "123");
        toDoEngine.createUser("admin", "123");
        verify(userStorageMock).createUser(user);
    }

At 3 line I create new object of user. At 4 line I pass another object. They are not the same, right? How does it know that object from line that I pass and object from 4 line are the same... By this method?

[Jeanne Boyarsky]

It calls the equals method. Which checks that the username/password are the same.

[must Janik]

Ahh.. Okey. What about getTasks?

List<Task> actual = toDoEngine.getTasks();

In my opinion, that's only bad implemented line. (Whole method in the first post)

[Jeanne Boyarsky]

getTasks() takes a user parameter so it had the same problem/solution.

[must Janik]

Jeanne Boyarsky wrote:getTasks() takes a user parameter so it had the same problem/solution.

Well, it doesn't work anyway.
Here is my stacktrace:

java.lang.AssertionError: 
Expected :[Task: wash]
Actual   :[]
 <Click to see difference>
 
 
    at org.junit.Assert.fail(Assert.java:88)
    at org.junit.Assert.failNotEquals(Assert.java:834)
    at org.junit.Assert.assertEquals(Assert.java:118)
    at org.junit.Assert.assertEquals(Assert.java:144)
    at controller.ToDoEngineTest.getTasks(ToDoEngineTest.java:54)
    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:564)
    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.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    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$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)