我的单元测试由于无法创建位图而失败 [英] my unit test fails due to Bitmap can not be created

问题描述

由于无法创建位图，因此我无法测试此 getGeneratedBitmap 函数.

I can not test this getGeneratedBitmap function, since Bitmap can not be created.

import android.graphics.Bitmap

class BitmapGenerator(query: String, private val width: Int, private val height: Int) {

    private var sizeExpansion: SizeExpansion = SizeExpansion(query, width, height)

    private var bitmap: Bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888)

    private var expandedQuery: String

    private var colors: IntArray

    private var colorsLength: Int = 0

    init {
        colorsLength = sizeExpansion.getExpectedLength()
        expandedQuery = sizeExpansion.getExpandedString()
        colors = IntArray(colorsLength)
        generateColorArray()
    }

    private fun generateColorArray(): IntArray {
        for (x in 0 until colorsLength) {
            colors[x] = ColorGenerator().generateColorAccToChar(expandedQuery[x])
        }
        return colors
    }

    fun getGeneratedBitmap(): Bitmap {
        bitmap.setPixels(colors, 0, width, 0, 0, width, height)
        return bitmap
    }
}

我尝试测试的方式是:

import org.junit.Test

import org.junit.Assert.*

class BitmapGeneratorTest {

@Test
fun getGeneratedBitmap() {
    assertNotEquals(BitmapGenerator("salih",25,25).getGeneratedBitmap(),null)
}
}

运行此测试时，它会在Bitmap.createBitmap

When I run this test, it throws exception on Bitmap.createBitmap

java.lang.IllegalStateException: Bitmap.createBitmap(widt… Bitmap.Config.ARGB_8888) must not be null

推荐答案

它位于(/src/test/java/)

it is at (/src/test/java/)

这些是JVM单元测试，无需任何Android运行时即可运行.通常，JVM单元测试是以Android平台方法返回默认值的方式配置的. null是返回引用类型(例如Bitmap.createBitmap())的方法的默认值.尝试将此null分配给Kotlin nonnull类型会导致运行时异常.

These are JVM unit tests that run without any Android runtime. Usually JVM unit tests are configured in a way where Android platform methods return default values. A null is a default value for a method returning a reference type, such as Bitmap.createBitmap(). Trying to assign this null to a Kotlin nonnull type causes the runtime exception.

两种常见方法:

• 以最小化Android SDK方法的表面积的方式重构代码，以便您可以使用简单的JVM单元测试来测试大多数代码.各种MV *架构模式可以为您提供帮助.

• Refactor your code in a way that the surface area to Android SDK methods is minimized so you can test most of your code with plain JVM unit tests. Various MV* architectural patterns help there.

在Android运行时上使用Android依赖项运行测试，即使其成为androidTest.

Run your tests with Android dependencies on an Android runtime, i.e. make it an androidTest.

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