即使具有相同的数据，断言也无法比较两个数据类答案

【问题标题】：Assert fails in comparing two data classes even though the have same data即使具有相同的数据，断言也无法比较两个数据类
【发布时间】：2023-04-06 07:52:01
【问题描述】：

我有两个数据类 - HindiTranslation 和 EnglishTranslation。我正在使用第三个数据类 - HindiAndEnglishTranslation，将它们映射到房间数据库中的一对多关系中。我试图通过断言给定和检索到的 HindiAndEnglishTranslation 对象是否相等来测试 Room Dao，但即使两个对象中的数据相同，测试也会失败。

印地语翻译：

@Entity(tableName = "hindi_translations")
data class HindiTranslation(
    @PrimaryKey
    var word: String,
    val hindiTranslation: String,
    val id: Long = randomNumberGenerator()
)

英文翻译：

@Entity(tableName = "english_translations")
data class EnglishTranslation(
    val translations: List<String>,
    val examples: List<String>,
    val usage: String,
    var parentKey: String,
    @PrimaryKey
    var englishId: Long = randomNumberGenerator(),
)

印地语和英语翻译：

data class HindiAndEnglishTranslation(
    @Embedded val hindi: HindiTranslation,
    @Relation(
        parentColumn = "word",
        entityColumn = "parentKey"
    )
    val englishTranslations: List<EnglishTranslation>
)

Dao 测试代码：

    @Test
    fun getAllTranslations() = runBlockingTest {
        //  Given - inserting a few hindi and corresponding english translations
        database.getTranslationDao().insertHindiTranslation(hindi1)
        database.getTranslationDao().insertEnglishTranslation(english1)
        database.getTranslationDao().insertHindiTranslation(hindi2)
        database.getTranslationDao().insertEnglishTranslation(english22)
        database.getTranslationDao().insertEnglishTranslation(english32)
        database.getTranslationDao().insertEnglishTranslation(english42)

        //  When - all translations in database are fetched
        val translations = database.getTranslationDao().getAllTranslations()

        //  Then - the loaded translations contain the expected values
        assertThat(translations, equalTo((listOf(hindiAndEnglish1, hindiAndEnglish2))))

    }

我得到的错误：

java.lang.AssertionError: 
Expected: <HindiAndEnglishTranslation(hindi=HindiTranslation(word=hot, hindiTranslation=गरम, id=6050220789869782304), englishTranslations=[EnglishTranslation(translations=[having a high degree of heat or a high temperature, (of food) containing or consisting of pungent spices or peppers which produce a burning sensation when tasted, passionately enthusiastic, eager, or excited], examples=[it was hot inside the hall, a very hot dish cooked with green chili, the idea had been nurtured in his hot imagination], usage=Adjective, parentKey=hot, englishId=133595475665305056)])>
     but: was <HindiAndEnglishTranslation(hindi=HindiTranslation(word=hot, hindiTranslation=गरम, id=6050220789869782304), englishTranslations=[EnglishTranslation(translations=[having a high degree of heat or a high temperature, (of food) containing or consisting of pungent spices or peppers which produce a burning sensation when tasted, passionately enthusiastic, eager,  or excited], examples=[it was hot inside the hall, a very hot dish cooked with green chili, the idea had been nurtured in his hot imagination], usage=Adjective, parentKey=hot, englishId=133595475665305056)])>

我做错了什么？

【问题讨论】：

标签： java android kotlin junit hamcrest

【解决方案1】：

您可能想要覆盖 hashcode 和 equals 方法。由于默认的 equals 方法是按引用而不是按数据进行比较。

【讨论】：

不适用于数据类
我不确定，但我认为数据类中的 equals 是按数据进行比较的。尽管如此，我也尝试过覆盖 equals 和 hashcode 方法，但没有成功。

【解决方案2】：

您应该使用assertContentEquals(expectedArray, actualArray) 而不是assertThat(expectedArray, actualArray)

【讨论】：

我会在哪个库中找到 assertContentEqual 方法？ Android Studio 无法识别此方法。
在 kotlin 1.5 中可用