Java:单元测试未返回正确的结果

Question

我正在编写一个程序，如果游戏没有任何评论，那么我需要将其添加到 map 中。如果游戏有评论，则将给定的评论添加到相应的 GameInfo 中。我的代码编译得很好，但我的单元测试没有返回我需要的点，以便它们返回以表明我的代码正在正确执行。这是我的代码:

class GameInfoCollection {
    // TODO - you need to use a Map (from a String, the title, to a GameInfo) to keep track of all the GameInfo's
    Map<String, Integer> titles = new HashMap<String, Integer>();
    // TODO - if there are no reviews for the game, create a new GameInfo  (with this review) and add it to the map
    // if there's one, add the given review to the corresponding GameInfo 
    public void addGameReview(String gameTitle, Review r)
    {
        if (titles.isEmpty()) {
            GameInfo g = new GameInfo("Review");
        } else titles.put(gameTitle, 1);

    }

    public int getNumberOfReviewsForGame(String gameTitle)
    {
        // TODO - implement this
        return titles.get(titles);
    }

这是我对这些方法的单元测试。它应该返回 20 分，但没有返回任何分:

public void testGetNumberOfReviewsForGame()
    {       
        GameInfoCollection gic=new GameInfoCollection();


        gic.addGameReview("g1",new Review("cool",5));
        gic.addGameReview("g1",new Review("cool",3));
        gic.addGameReview("g2",new Review("cool",2));
        gic.addGameReview("g3",new Review("cool",2));

        Assert.assertEquals(2,gic.getNumberOfReviewsForGame("g1"));
        Assert.assertEquals(1,gic.getNumberOfReviewsForGame("g2"));
        gic.addGameReview("g1",new Review("cool",3));
        Assert.assertEquals(3,gic.getNumberOfReviewsForGame("g1"));
    }

    @Grade(points=20)
    @Test

这是我的整个程序的代码。请注意，最后有一些部分我还没有完成。

package assignment;

import java.text.MessageFormat;
import java.util.Scanner;

import java.awt.Point;
import java.awt.Dimension;
import java.awt.Rectangle;

import java.time.LocalDate;

import java.util.*; // List, ArrayList, Map, HashMap

class Review {
    public String reviewText;
    public int numberOfStars;

    public Review(String reviewText, int numberOfStars) {
        this.reviewText=reviewText;
        this.numberOfStars=numberOfStars;
    }
}

class GameInfo {
    private String title;
    // need an ArrayList to keep the reviews;
    private Review[] reviews = new Review[10];
    int numReviews=0;

    public GameInfo(String title) {
        this.title=title;
        // you may want to initialize any other variables you create here
    }

    public String getTitle() {
        return title;
    }

    // TODO - adds the review to the 'array' of reviews. You need to keep all reviews in an array
    public void addReview(Review r) {
        reviews[numReviews] = r;
        ++numReviews;
    }

    // TODO - returns the number of reviews which have been added to this GameInfo
    public int getNumberOfReviews() {
        return numReviews;
    }

    // TODO - returns the sum of the number of stars which have been added to this GameInfo
    // you have to calculate this from your array
    public int getSumOfStars() {
        int sum=0;
        for (int i=0; i<numReviews;++i)
            sum +=reviews[i].numberOfStars;
        return sum;
    }

    // TODO - returns the average number of stars for this GameInfo's reviews
    // again, have to calculate this (or at least the sum of stars) from your array
    public double getAverageStarRating() {
        double firstNumber = getSumOfStars();
        double secondNumber = getNumberOfReviews();
        double avg = firstNumber/secondNumber;

        return avg;
    }
}

// TODO - you need to implement all these methods
class GameInfoCollection {
    // TODO - you need to use a Map (from a String, the title, to a GameInfo) to keep track of all the GameInfo's
    Map<String, Integer> titles = new HashMap<String, Integer>();
    // TODO - if there are no reviews for the game, create a new GameInfo  (with this review) and add it to the map
    // if there's one, add the given review to the corresponding GameInfo 
    public void addGameReview(String gameTitle, Review r)
    {
        if (titles.isEmpty()) {
            GameInfo g = new GameInfo("Review");
        } else titles.put(gameTitle, 1);

    }

    public int getNumberOfReviewsForGame(String gameTitle)
    {
        // TODO - implement this
        return titles.get(titles);
    }

请注意，我对 Java 还很陌生，非常感谢您的帮助。谢谢!

Answer 1

这看起来像是一项家庭作业，我猜单元测试是您老师提供的代码的一部分。单元测试失败的事实并不意味着单元测试是错误的，而是意味着您的代码行为不正确。特别是GameInfoCollection中的部分你还没有完成。

那么，让我们看一下每个 TODO 注释的含义:

// TODO - you need to use a Map (from a String, the title, to a GameInfo) to keep track of all the GameInfo's

Map 具有键和值，据说是从键映射到值。在声明中Map<String, Integer> ，第一个类型(String)是键的类型，第二个是值的类型。这里的 TODO 是说值的类型需要是 GameInfo .

// TODO - if there are no reviews for the game, create a new GameInfo  (with this review) and add it to the map

这一切的每个部分都需要在 if 内完成分支。您需要 a) 创建一个新的 GameInfo ，b) 将评论放入其中，c) 将其添加到 map 中。您当前只执行 a) 部分，即使如此，您也没有将正确的值传递给构造函数 - 看看 GameInfo构造函数及其所采用的参数名称； “评论”与此相符吗？

// if there's one, add the given review to the corresponding GameInfo 

这是关于 else 中应该包含的内容。分支。

// TODO - implement this

从技术上讲，此方法已经有一个实现，但您需要对其进行更改以正确匹配第一个 TODO 中关于 map 值类型的更改。