Question

如何断言对象与更好的错误相等。

让我们说我们有一类卡车：

import java.util.List;

public class Truck {

    private String model;
    private String make;
    private int year;

    public Truck(String model, String make, int year) {
        super();
        this.model = model;
        this.make = make;
        this.year = year;
    }

    public String getModel() {
        return model;
    }

    public void setModel(String model) {
        this.model = model;
    }

    public String getMake() {
        return make;
    }

    public void setMake(String make) {
        this.make = make;
    }

    public int getYear() {
        return year;
    }

    public void setYear(int year) {
        this.year = year;
    }
}

测试：

@Test
public void truckTest () {

    Truck pickupTruck1 = new Truck("Big 10", "Chevy", 1976);
    Truck pickupTruck2 = new Truck("Big 10", "Chevy", 1975);

    //assertThat(pickupTruck1, equalTo(pickupTruck2));
    //this error is not help full java.lang.AssertionError:
    //Expected: <com.tests.tests.library.Truck@59c0fef4>
    //but: was <com.tests.tests.library.Truck@da27335>

    assertThat(pickupTruck1, samePropertyValuesAs(pickupTruck2));
}

Bellow错误很有用：

java.lang.AssertionError:
Expected: same property values as Truck [make: "Chevy", model: "Big 10", parts: null, year: <1975>]
     but: year was <1976>

现在假设我们更新Truck对象有点复杂：

package com.tests.tests.library;

import java.util.List;

public class Truck {

private String model;
private String make;
private int year;
private List<TruckPartsObject> parts;


public Truck(String model, String make, int year) {
    super();
    this.model = model;
    this.make = make;
    this.year = year;
    }

    public String getModel() {
    return model;
    }

    public void setModel(String model) {
    this.model = model;
    }

    public String getMake() {
    return make;
    }

    public void setMake(String make) {
    this.make = make;
    }

    public int getYear() {
    return year;
    }

    public void setYear(int year) {
    this.year = year;
    }

    public List<TruckPartsObject> getParts() {
    return parts;
    }

    public void setParts(List<TruckPartsObject> parts) {
    this.parts = parts;
    }
}

添加TruckPartsObject：

import java.util.HashMap;

public class TruckPartsObject {

    private String name;
    private String price;
    private HashMap<String, String> partsHashMap;

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPrice() {
        return price;
    }
    public void setPrice(String price) {
        this.price = price;
    }
    public HashMap<String, String> getPartsHashMap() {
        return partsHashMap;
    }
    public void setPartsHashMap(HashMap<String, String> partsHashMap) {
        this.partsHashMap = partsHashMap;
    }
}

更新测试：

@Test
public void truckTest () {

    Truck pickupTruck1 = new Truck("Big 10", "Chevy", 1976);
    Truck pickupTruck2 = new Truck("Big 10", "Chevy", 1975);               

    List<TruckPartsObject> parts = new ArrayList<TruckPartsObject>();
    TruckPartsObject truckPartsObject = new TruckPartsObject();
    truckPartsObject.setName("part1");
    parts.add(truckPartsObject);
    pickupTruck1.setParts(parts);

    assertThat(pickupTruck1, samePropertyValuesAs(pickupTruck2));
}

输出：

java.lang.AssertionError:
Expected: same property values as Truck [make: "Chevy", model: "Big 10", parts: null, year: <1975>]
     but: parts was <[com.tests.tests.library.TruckPartsObject@11c03d7b]>

如何将最后一个输出修复为原始输出有用。它告诉我为什么对象不等于。希望使测试运行输出可读且易于调试。

I tried implementing equals method in the truck object but when the assert fails then then the message is still not helpful.

将卡车对象更新为等于方法：

@Override
    public boolean equals(Object obj) {

        Truck MyTruck = (Truck) obj;
        if(this.year == MyTruck.year)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

更新测试：

assertThat(pickupTruck1, equalTo(pickupTruck2));

输出：

java.lang.AssertionError:
Expected: <com.tests.tests.library.Truck@38862c65>
     but: was <com.tests.tests.library.Truck@70ccb7e0>

Answer 1

在任何情况下，为了获得良好的输出，您应始终覆盖operator(6) = "110"

operator(6) = operator(6 / 2) + (6 % 2)
            = operator(3) + 0
            = operator(3 / 2) + (3 % 2) + 0
            = operator(1) + 1 + 0
            = operator(1 / 2) + (1 % 2) + 1 + 0
            = operator(0) + 1 + 1 + 0
            = "" + 1 + 1 + 0
            = "110"

如何断言对象在测试中是否相同且错误更好？

1 个答案: