Use anonymous system FS subclasses

Author: fzhinkin

core/js/src/files/FileSystemJs.kt

@@ -25,11 +25,7 @@ internal val os: dynamic
         }
     }
 
-private class JsFileSystem : SystemFileSystemImpl() {
-    companion object {
-        val Instance = JsFileSystem()
-    }
-
+internal actual val SystemFileSystem: FileSystem = object : SystemFileSystemImpl() {
     override fun exists(path: Path): Boolean {
         check(fs !== null) { "Module 'fs' was not found" }
         return fs.existsSync(path.path) as Boolean
@@ -104,8 +100,6 @@ private class JsFileSystem : SystemFileSystemImpl() {
     }
 }
 
-internal actual val SystemFileSystem: FileSystem = JsFileSystem.Instance
-
 internal actual val SystemTemporaryDirectoryImpl: Path
     get() {
         check(os !== null) { "Module 'os' was not found" }

core/jvm/src/files/FileSystemJvm.kt

@@ -41,10 +41,8 @@ private val mover: Mover by lazy {
     }
 }
 
-private class JvmFileSystem : SystemFileSystemImpl() {
-    companion object {
-        val Instance = JvmFileSystem()
-    }
+@JvmField
+internal actual val SystemFileSystem: FileSystem = object : SystemFileSystemImpl() {
 
     override fun exists(path: Path): Boolean {
         return path.file.exists()
@@ -64,7 +62,7 @@ private class JvmFileSystem : SystemFileSystemImpl() {
 
     override fun createDirectories(path: Path, mustCreate: Boolean) {
         if (!path.file.mkdirs() && mustCreate) {
-            throw IOException("Path already exist: ${path}")
+            throw IOException("Path already exist: $path")
         }
     }
 
@@ -79,8 +77,6 @@ private class JvmFileSystem : SystemFileSystemImpl() {
     }
 }
 
-internal actual val SystemFileSystem: FileSystem = JvmFileSystem.Instance
-
 internal actual val SystemTemporaryDirectoryImpl: Path
     get() = Path(System.getProperty("java.io.tmpdir"))
 

core/native/src/files/FileSystemNative.kt

@@ -9,11 +9,7 @@ import kotlinx.cinterop.*
 import kotlinx.io.IOException
 import platform.posix.*
 
-private class NativeFileSystem : SystemFileSystemImpl() {
-    companion object {
-        val Instance = NativeFileSystem()
-    }
-
+internal actual val SystemFileSystem: FileSystem = object : SystemFileSystemImpl() {
     override fun exists(path: Path): Boolean {
         return access(path.path, F_OK) == 0
     }
@@ -82,9 +78,6 @@ internal expect fun atomicMoveImpl(source: Path, destination: Path)
 
 internal expect fun mkdirImpl(path: String)
 
-internal actual val SystemFileSystem: FileSystem
-    get() = NativeFileSystem.Instance
-
 public actual open class FileNotFoundException actual constructor(
     message: String?
 ) : IOException(message)