test: Improve unit test for 'sketch-core' module

internal/test-utils-core/src/androidMain/kotlin/com/github/panpf/sketch/test/utils/bitmaps.kt

@@ -19,6 +19,15 @@ package com.github.panpf.sketch.test.utils
 import android.graphics.Bitmap
 
 
+fun Bitmap.toSizeString(): String = "${width}x${height}"
+
+@Suppress("USELESS_ELVIS")
+val Bitmap.configOrNull: Bitmap.Config?
+    get() = config ?: null
+
+fun Bitmap.toShortInfoString(): String = "Bitmap(${width}x${height},$configOrNull)"
+
+
 val Bitmap.cornerA: Int
     get() = getPixel(0, 0)
 val Bitmap.cornerB: Int
@@ -32,12 +41,4 @@ fun Bitmap.corners(block: Bitmap.() -> List<Int>): List<Int> {
     return block(this)
 }
 
-fun Bitmap.toSizeString(): String = "${width}x${height}"
-
-fun Bitmap.corners(): List<Int> = listOf(cornerA, cornerB, cornerC, cornerD)
-
-@Suppress("USELESS_ELVIS")
-val Bitmap.configOrNull: Bitmap.Config?
-    get() = config ?: null
-
-fun Bitmap.toShortInfoString(): String = "Bitmap(${width}x${height},$configOrNull)"
+fun Bitmap.corners(): List<Int> = listOf(cornerA, cornerB, cornerC, cornerD)

internal/test-utils-core/src/androidMain/kotlin/com/github/panpf/sketch/test/utils/images.android.kt

@@ -1,6 +1,7 @@
 package com.github.panpf.sketch.test.utils
 
 import android.graphics.Bitmap
+import androidx.core.graphics.get
 import com.github.panpf.sketch.AndroidBitmapImage
 import com.github.panpf.sketch.Image
 import com.github.panpf.sketch.asSketchImage
@@ -13,4 +14,13 @@ actual fun createImage(width: Int, height: Int): Image {
 
 actual fun createCacheValue(image: Image, extras: Map<String, Any?>): MemoryCache.Value {
     return AndroidBitmapImageValue(image = image as AndroidBitmapImage, extras = extras)
+}
+
+actual fun Image.hasAlpha(): Boolean = (this as AndroidBitmapImage).bitmap.hasAlpha()
+
+/**
+ * Returns the Color at the specified location.
+ */
+actual fun Image.getPixel(x: Int, y: Int): Int {
+    return (this as AndroidBitmapImage).bitmap.get(x, y)
 }

internal/test-utils-core/src/commonMain/kotlin/com/github/panpf/sketch/test/utils/images.common.kt

@@ -5,4 +5,26 @@ import com.github.panpf.sketch.cache.MemoryCache
 
 expect fun createImage(width: Int, height: Int): Image
 
-expect fun createCacheValue(image: Image, extras: Map<String, Any?>): MemoryCache.Value
+expect fun createCacheValue(image: Image, extras: Map<String, Any?>): MemoryCache.Value
+
+val Image.cornerA: Int
+    get() = getPixel(0, 0)
+val Image.cornerB: Int
+    get() = getPixel(width - 1, 0)
+val Image.cornerC: Int
+    get() = getPixel(width - 1, height - 1)
+val Image.cornerD: Int
+    get() = getPixel(0, height - 1)
+
+fun Image.corners(block: Image.() -> List<Int>): List<Int> {
+    return block(this)
+}
+
+fun Image.corners(): List<Int> = listOf(cornerA, cornerB, cornerC, cornerD)
+
+expect fun Image.hasAlpha(): Boolean
+
+/**
+ * Returns the Color at the specified location.
+ */
+expect fun Image.getPixel(x: Int, y: Int): Int

internal/test-utils-core/src/nonAndroidMain/kotlin/com/github/panpf/sketch/test/utils/images.nonAndroid.kt

@@ -6,6 +6,8 @@ import com.github.panpf.sketch.SkiaBitmapImage
 import com.github.panpf.sketch.asSketchImage
 import com.github.panpf.sketch.cache.MemoryCache
 import com.github.panpf.sketch.cache.SkiaBitmapImageValue
+import com.github.panpf.sketch.util.getPixel
+import com.github.panpf.sketch.util.hasAlpha
 
 actual fun createImage(width: Int, height: Int): Image {
     return SkiaBitmap().apply {
@@ -15,4 +17,14 @@ actual fun createImage(width: Int, height: Int): Image {
 
 actual fun createCacheValue(image: Image, extras: Map<String, Any?>): MemoryCache.Value {
     return SkiaBitmapImageValue(image = image as SkiaBitmapImage, extras = extras)
+}
+
+//actual fun Image.hasAlpha(): Boolean = !(this as SkiaBitmapImage).bitmap.isOpaque
+actual fun Image.hasAlpha(): Boolean = (this as SkiaBitmapImage).bitmap.hasAlpha()
+
+/**
+ * Returns the Color at the specified location.
+ */
+actual fun Image.getPixel(x: Int, y: Int): Int {
+    return (this as SkiaBitmapImage).bitmap.getPixel(x, y)
 }

sketch-core/src/commonMain/kotlin/com/github/panpf/sketch/transform/BlurTransformation.common.kt

@@ -31,6 +31,8 @@ internal expect fun blurTransformation(
 
 /**
  * Bitmap blur transformation
+ *
+ * @see com.github.panpf.sketch.core.common.test.transform.BlurTransformationTest
  */
 class BlurTransformation constructor(
     /** Blur radius */
@@ -86,12 +88,27 @@ class BlurTransformation constructor(
     }
 }
 
+/**
+ * Create a blur transform record
+ *
+ * @see com.github.panpf.sketch.core.common.test.transform.BlurTransformationTest.testBlurTransformed
+ */
 fun createBlurTransformed(
     radius: Int, hasAlphaBitmapBgColor: Int?, maskColor: Int?
 ) = "BlurTransformed($radius,$hasAlphaBitmapBgColor,$maskColor)"
 
+/**
+ * Check if the transformed string is a blur transformation
+ *
+ * @see com.github.panpf.sketch.core.common.test.transform.BlurTransformationTest.testBlurTransformed
+ */
 fun isBlurTransformed(transformed: String): Boolean =
     transformed.startsWith("BlurTransformed(")
 
+/**
+ * Get the blur transformation record from the transformed record list
+ *
+ * @see com.github.panpf.sketch.core.common.test.transform.BlurTransformationTest.testBlurTransformed
+ */
 fun List<String>.getBlurTransformed(): String? =
     find { isBlurTransformed(it) }