Make ResourceReader a public API (#5334)

Describe proposed changes and the issue being fixed

Fixes
[CMP-8134](https://youtrack.jetbrains.com/issue/CMP-8134/Switch-the-ClassLoader-used-by-ResourceReader)


## Testing
- [x] Add Test to **desktopTest** SourceSet
- (Optional) This should be tested by QA

## Release Notes
### Features - Resources
- Added `JvmResourceReader` API and made `LocalResourceReader` public to
allow providing a custom classloader for desktop target

components/resources/library/build.gradle.kts

@@ -217,3 +217,13 @@ tasks.register<GeneratePluralRuleListsTask>("generatePluralRuleLists") {
     outputFile = projectDir.file("src/commonMain/kotlin/org/jetbrains/compose/resources/plural/CLDRPluralRuleLists.kt")
     samplesOutputFile = projectDir.file("src/commonTest/kotlin/org/jetbrains/compose/resources/CLDRPluralRuleLists.test.kt")
 }
+
+tasks {
+    val desktopTestProcessResources =
+        named<ProcessResources>("desktopTestProcessResources")
+
+    withType<Test> {
+        dependsOn(desktopTestProcessResources)
+        environment("RESOURCES_PATH", desktopTestProcessResources.map { it.destinationDir.absolutePath }.get())
+    }
+}

components/resources/library/src/androidMain/kotlin/org/jetbrains/compose/resources/ResourceReader.android.kt

@@ -8,7 +8,11 @@ import androidx.compose.runtime.ProvidableCompositionLocal
 import java.io.FileNotFoundException
 import java.io.InputStream
 
-internal actual fun getPlatformResourceReader(): ResourceReader = object : ResourceReader {
+@ExperimentalResourceApi
+internal actual fun getPlatformResourceReader(): ResourceReader = DefaultAndroidResourceReader
+
+@ExperimentalResourceApi
+internal object DefaultAndroidResourceReader : ResourceReader {
     private val assets: AssetManager by lazy {
         val context = androidContext ?: error(
             "Android context is not initialized. " +

components/resources/library/src/commonMain/kotlin/org/jetbrains/compose/resources/ResourceReader.kt

@@ -24,7 +24,8 @@ suspend fun readResourceBytes(path: String): ByteArray = DefaultResourceReader.r
 @InternalResourceApi
 fun getResourceUri(path: String): String = DefaultResourceReader.getUri(path)
 
-internal interface ResourceReader {
+@ExperimentalResourceApi
+interface ResourceReader {
     suspend fun read(path: String): ByteArray
     suspend fun readPart(path: String, offset: Long, size: Long): ByteArray
     fun getUri(path: String): String
@@ -32,10 +33,12 @@ internal interface ResourceReader {
 
 internal expect fun getPlatformResourceReader(): ResourceReader
 
+@ExperimentalResourceApi
 internal val DefaultResourceReader = getPlatformResourceReader()
 
 //ResourceReader provider will be overridden for tests
-internal val LocalResourceReader = staticCompositionLocalOf { DefaultResourceReader }
+@ExperimentalResourceApi
+val LocalResourceReader = staticCompositionLocalOf { DefaultResourceReader }
 
 //For an android preview we need to initialize the resource reader with the local context
 internal expect val ProvidableCompositionLocal<ResourceReader>.currentOrPreview: ResourceReader

components/resources/library/src/desktopMain/kotlin/org/jetbrains/compose/resources/ResourceReader.desktop.kt

@@ -1,10 +1,20 @@
 package org.jetbrains.compose.resources
 
-import java.io.EOFException
-import java.io.IOException
 import java.io.InputStream
 
-internal actual fun getPlatformResourceReader(): ResourceReader = object : ResourceReader {
+@ExperimentalResourceApi
+internal actual fun getPlatformResourceReader(): ResourceReader =
+    JvmResourceReader.Default
+
+@ExperimentalResourceApi
+class JvmResourceReader(
+    private val classLoader: ClassLoader
+) : ResourceReader {
+
+    companion object {
+        internal val Default = JvmResourceReader(JvmResourceReader::class.java.classLoader)
+    }
+
     override suspend fun read(path: String): ByteArray {
         val resource = getResourceAsStream(path)
         return resource.use { input -> input.readBytes() }
@@ -31,17 +41,12 @@ internal actual fun getPlatformResourceReader(): ResourceReader = object : Resou
     }
 
     override fun getUri(path: String): String {
-        val classLoader = getClassLoader()
         val resource = classLoader.getResource(path) ?: throw MissingResourceException(path)
         return resource.toURI().toString()
     }
 
     private fun getResourceAsStream(path: String): InputStream {
-        val classLoader = getClassLoader()
         return classLoader.getResourceAsStream(path) ?: throw MissingResourceException(path)
     }
 
-    private fun getClassLoader(): ClassLoader {
-        return this.javaClass.classLoader ?: error("Cannot find class loader")
-    }
 }

components/resources/library/src/desktopTest/kotlin/org/jetbrains/compose/resources/CustomClassloaderTest.kt

@@ -0,0 +1,39 @@
+@file:OptIn(ExperimentalTestApi::class)
+
+package org.jetbrains.compose.resources
+
+import androidx.compose.ui.test.ExperimentalTestApi
+import kotlinx.coroutines.test.runTest
+import java.net.URLClassLoader
+import kotlin.io.path.Path
+import kotlin.io.path.isDirectory
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+
+class CustomClassloaderTest {
+
+    val RESOURCES_PATH
+        get() = System.getenv("RESOURCES_PATH")
+            ?.let { Path(it) }
+            ?.takeIf { it.isDirectory() }
+            ?: error("RESOURCES_PATH environment variable is not set or is not a directory")
+
+    @Test
+    fun testCustomClassloader() = runTest {
+        val actualResourceText =
+            CustomClassloaderTest::class
+                .java
+                .classLoader
+                .getResourceAsStream("hello.txt")
+                ?.readAllBytes()
+                ?.toString(Charsets.UTF_8)
+
+        val classloader = URLClassLoader(arrayOf(RESOURCES_PATH.toUri().toURL()), null)
+        val reader = JvmResourceReader(classloader)
+        assertEquals(
+            expected = actualResourceText,
+            actual = reader.read("hello.txt").toString(Charsets.UTF_8)
+        )
+    }
+}

components/resources/library/src/desktopTest/resources/hello.txt

@@ -0,0 +1 @@
+Hello World!

components/resources/library/src/iosMain/kotlin/org/jetbrains/compose/resources/ResourceReader.ios.kt

@@ -25,8 +25,12 @@ import platform.Foundation.readDataOfLength
 import platform.Foundation.seekToFileOffset
 import platform.posix.memcpy
 
+@ExperimentalResourceApi
 @OptIn(BetaInteropApi::class)
-internal actual fun getPlatformResourceReader(): ResourceReader = object : ResourceReader {
+internal actual fun getPlatformResourceReader(): ResourceReader = DefaultIOsResourceReader
+
+@ExperimentalResourceApi
+internal object DefaultIOsResourceReader : ResourceReader {
     private val composeResourcesDir: String by lazy { findComposeResourcesPath() }
 
     override suspend fun read(path: String): ByteArray {

components/resources/library/src/jsMain/kotlin/org/jetbrains/compose/resources/ResourceReader.js.kt

@@ -9,12 +9,14 @@ import org.w3c.files.Blob
 import org.w3c.xhr.XMLHttpRequest
 import kotlin.js.Promise
 
+@ExperimentalResourceApi
 internal actual fun getPlatformResourceReader(): ResourceReader {
     if (isInTestEnvironment()) return TestJsResourceReader
     return DefaultJsResourceReader
 }
 
-private val DefaultJsResourceReader = object : ResourceReader {
+@ExperimentalResourceApi
+internal object DefaultJsResourceReader : ResourceReader {
     override suspend fun read(path: String): ByteArray {
         return readAsBlob(path).asByteArray()
     }
@@ -46,36 +48,34 @@ private val DefaultJsResourceReader = object : ResourceReader {
 }
 
 // It uses a synchronous XmlHttpRequest (blocking!!!)
-private val TestJsResourceReader by lazy {
-    object : ResourceReader {
-        override suspend fun read(path: String): ByteArray {
-            return readByteArray(path)
-        }
+private object TestJsResourceReader : ResourceReader {
+    override suspend fun read(path: String): ByteArray {
+        return readByteArray(path)
+    }
 
-        override suspend fun readPart(path: String, offset: Long, size: Long): ByteArray {
-            return readByteArray(path).sliceArray(offset.toInt() until (offset + size).toInt())
-        }
+    override suspend fun readPart(path: String, offset: Long, size: Long): ByteArray {
+        return readByteArray(path).sliceArray(offset.toInt() until (offset + size).toInt())
+    }
 
-        override fun getUri(path: String): String {
-            val location = window.location
-            return getResourceUrl(location.origin, location.pathname, path)
-        }
+    override fun getUri(path: String): String {
+        val location = window.location
+        return getResourceUrl(location.origin, location.pathname, path)
+    }
 
-        private fun readByteArray(path: String): ByteArray {
-            val resPath = WebResourcesConfiguration.getResourcePath(path)
-            val request = XMLHttpRequest()
-            request.open("GET", resPath, false)
-            request.overrideMimeType("text/plain; charset=x-user-defined")
-            request.send()
-            if (request.status == 200.toShort()) {
-                // For blocking XmlHttpRequest the response can be only in text form, so we convert it to bytes manually
-                val text = request.responseText
-                val bytes = Uint8Array(text.length)
-                js("for (var i = 0; i < text.length; i++) { bytes[i] = text.charCodeAt(i) & 0xFF; }")
-                return bytes.unsafeCast<ByteArray>()
-            }
-            throw MissingResourceException("$resPath")
+    private fun readByteArray(path: String): ByteArray {
+        val resPath = WebResourcesConfiguration.getResourcePath(path)
+        val request = XMLHttpRequest()
+        request.open("GET", resPath, false)
+        request.overrideMimeType("text/plain; charset=x-user-defined")
+        request.send()
+        if (request.status == 200.toShort()) {
+            // For blocking XmlHttpRequest the response can be only in text form, so we convert it to bytes manually
+            val text = request.responseText
+            val bytes = Uint8Array(text.length)
+            js("for (var i = 0; i < text.length; i++) { bytes[i] = text.charCodeAt(i) & 0xFF; }")
+            return bytes.unsafeCast<ByteArray>()
         }
+        throw MissingResourceException("$resPath")
     }
 }
 

components/resources/library/src/macosMain/kotlin/org/jetbrains/compose/resources/ResourceReader.macos.kt

@@ -2,10 +2,21 @@ package org.jetbrains.compose.resources
 
 import kotlinx.cinterop.addressOf
 import kotlinx.cinterop.usePinned
-import platform.Foundation.*
+import platform.Foundation.NSBundle
+import platform.Foundation.NSData
+import platform.Foundation.NSFileHandle
+import platform.Foundation.NSFileManager
+import platform.Foundation.NSURL
+import platform.Foundation.closeFile
+import platform.Foundation.fileHandleForReadingAtPath
+import platform.Foundation.readDataOfLength
 import platform.posix.memcpy
 
-internal actual fun getPlatformResourceReader(): ResourceReader = object : ResourceReader {
+@ExperimentalResourceApi
+internal actual fun getPlatformResourceReader(): ResourceReader = DefaultMacOsResourceReader
+
+@ExperimentalResourceApi
+internal object DefaultMacOsResourceReader : ResourceReader {
     override suspend fun read(path: String): ByteArray {
         val data = readData(getPathOnDisk(path))
         return ByteArray(data.length.toInt()).apply {

components/resources/library/src/wasmJsMain/kotlin/org/jetbrains/compose/resources/ResourceReader.wasmJs.kt

@@ -23,12 +23,14 @@ private external fun jsExportInt8ArrayToWasm(src: Int8Array, size: Int, dstAddr:
 @JsFun("(blob) => blob.arrayBuffer()")
 private external fun jsExportBlobAsArrayBuffer(blob: Blob): Promise<ArrayBuffer>
 
+@ExperimentalResourceApi
 internal actual fun getPlatformResourceReader(): ResourceReader {
     if (isInTestEnvironment()) return TestWasmResourceReader
     return DefaultWasmResourceReader
 }
 
-private val DefaultWasmResourceReader = object : ResourceReader {
+@ExperimentalResourceApi
+internal object DefaultWasmResourceReader : ResourceReader {
     override suspend fun read(path: String): ByteArray {
         return readAsBlob(path).asByteArray()
     }
@@ -72,45 +74,43 @@ private val DefaultWasmResourceReader = object : ResourceReader {
 }
 
 // It uses a synchronous XmlHttpRequest (blocking!!!)
-private val TestWasmResourceReader by lazy {
-    object : ResourceReader {
-        override suspend fun read(path: String): ByteArray {
-            return readByteArray(path)
-        }
+private object TestWasmResourceReader : ResourceReader {
+    override suspend fun read(path: String): ByteArray {
+        return readByteArray(path)
+    }
 
-        override suspend fun readPart(path: String, offset: Long, size: Long): ByteArray {
-            return readByteArray(path).sliceArray(offset.toInt() until (offset + size).toInt())
-        }
+    override suspend fun readPart(path: String, offset: Long, size: Long): ByteArray {
+        return readByteArray(path).sliceArray(offset.toInt() until (offset + size).toInt())
+    }
 
-        override fun getUri(path: String): String {
-            val location = window.location
-            return getResourceUrl(location.origin, location.pathname, path)
-        }
+    override fun getUri(path: String): String {
+        val location = window.location
+        return getResourceUrl(location.origin, location.pathname, path)
+    }
 
-        private fun readByteArray(path: String): ByteArray {
-            val resPath = WebResourcesConfiguration.getResourcePath(path)
-            val request = XMLHttpRequest()
-            request.open("GET", resPath, false)
-            request.overrideMimeType("text/plain; charset=x-user-defined")
-            request.send()
-            if (request.status == 200.toShort()) {
-                return requestResponseAsByteArray(request).asByteArray()
-            }
-            println("Request status is not 200 - $resPath, status: ${request.status}")
-            throw MissingResourceException("$resPath")
+    private fun readByteArray(path: String): ByteArray {
+        val resPath = WebResourcesConfiguration.getResourcePath(path)
+        val request = XMLHttpRequest()
+        request.open("GET", resPath, false)
+        request.overrideMimeType("text/plain; charset=x-user-defined")
+        request.send()
+        if (request.status == 200.toShort()) {
+            return requestResponseAsByteArray(request).asByteArray()
         }
+        println("Request status is not 200 - $resPath, status: ${request.status}")
+        throw MissingResourceException(resPath)
+    }
+
+    private fun Int8Array.asByteArray(): ByteArray {
+        val array = this
+        val size = array.length
 
-        private fun Int8Array.asByteArray(): ByteArray {
-            val array = this
-            val size = array.length
-
-            @OptIn(UnsafeWasmMemoryApi::class)
-            return withScopedMemoryAllocator { allocator ->
-                val memBuffer = allocator.allocate(size)
-                val dstAddress = memBuffer.address.toInt()
-                jsExportInt8ArrayToWasm(array, size, dstAddress)
-                ByteArray(size) { i -> (memBuffer + i).loadByte() }
-            }
+        @OptIn(UnsafeWasmMemoryApi::class)
+        return withScopedMemoryAllocator { allocator ->
+            val memBuffer = allocator.allocate(size)
+            val dstAddress = memBuffer.address.toInt()
+            jsExportInt8ArrayToWasm(array, size, dstAddress)
+            ByteArray(size) { i -> (memBuffer + i).loadByte() }
         }
     }
 }