IJPL-194952 Revert "[eel] IJPL-172897: remove EelPath.OS, use only EelPlatform in the API"

This reverts commit 1a1b6768


(cherry picked from commit f07a5eac3280186c0f27e156a70498a7ed962469)

IJ-MR-167682

GitOrigin-RevId: db14b1563fc992df3842d3407321bf2cc67381e9

java/idea-ui/testSrc/com/intellij/ui/ProjectWizardJdkComboBoxTest.kt

@@ -9,7 +9,6 @@ import com.intellij.openapi.projectRoots.ProjectJdkTable
 import com.intellij.openapi.projectRoots.Sdk
 import com.intellij.openapi.projectRoots.SimpleJavaSdkType
 import com.intellij.openapi.util.Disposer
-import com.intellij.platform.eel.EelPlatform
 import com.intellij.platform.eel.path.EelPath
 import com.intellij.platform.eel.provider.LocalEelDescriptor
 import com.intellij.platform.eel.provider.utils.EelPathUtils
@@ -25,7 +24,7 @@ import java.nio.file.Path
 
 @TestApplication
 class ProjectWizardJdkComboBoxTest {
-  val eelFixture = eelFixture(EelPlatform.Linux(EelPlatform.Arch.Unknown))
+  val eelFixture = eelFixture(EelPath.OS.UNIX)
 
   @Test
   fun `changing eel changes available sdks`(@TestDisposable disposable: Disposable): Unit = timeoutRunBlocking {

platform/eel-impl/src/com/intellij/platform/eel/impl/fs/LocalEelFileSystemApi.kt

@@ -27,6 +27,8 @@ import kotlin.io.path.fileStore
 import kotlin.streams.asSequence
 
 abstract class NioBasedEelFileSystemApi(@VisibleForTesting val fs: FileSystem) : EelFileSystemApi {
+  abstract val pathOs: EelPath.OS
+
   protected fun EelPath.toNioPath(): Path =
     fs.getPath(toString())
 
@@ -335,6 +337,7 @@ abstract class PosixNioBasedEelFileSystemApi(
   fs: FileSystem,
   override val user: EelUserPosixInfo,
 ) : NioBasedEelFileSystemApi(fs), LocalEelFileSystemPosixApi {
+  override val pathOs: EelPath.OS = EelPath.OS.UNIX
 
   override suspend fun createDirectory(
     path: EelPath,
@@ -404,6 +407,7 @@ abstract class WindowsNioBasedEelFileSystemApi(
   fs: FileSystem,
   override val user: EelUserWindowsInfo,
 ) : NioBasedEelFileSystemApi(fs), LocalEelFileSystemWindowsApi {
+  override val pathOs: EelPath.OS = EelPath.OS.WINDOWS
 
   override suspend fun getRootDirectories(): Collection<EelPath> =
     FileSystems.getDefault().rootDirectories.map { path ->

platform/eel-impl/src/com/intellij/platform/eel/impl/local/LocalEelApiImpl.kt

@@ -62,10 +62,18 @@ class LocalPosixEelApiImpl(private val nioFs: FileSystem = FileSystems.getDefaul
     check(SystemInfo.isUnix)
   }
 
-  override val platform: EelPlatform.Posix = when {
-    SystemInfo.isMac -> EelPlatform.Darwin(CpuArch.CURRENT.toEelArch())
-    SystemInfo.isFreeBSD -> EelPlatform.FreeBSD(CpuArch.CURRENT.toEelArch())
-    else -> EelPlatform.Linux(CpuArch.CURRENT.toEelArch())
+  override val platform: EelPlatform.Posix
+    get() {
+      val arch = CpuArch.CURRENT.toEelArch()
+      return when {
+        SystemInfo.isMac -> EelPlatform.Darwin(arch)
+        SystemInfo.isLinux -> EelPlatform.Linux(arch)
+        SystemInfo.isFreeBSD -> EelPlatform.FreeBSD(arch)
+        else -> {
+          LOG.info("Eel is not supported on current platform")
+          EelPlatform.Linux(arch)
+        }
+      }
     }
 
   override val tunnels: EelTunnelsPosixApi get() = EelLocalTunnelsApiImpl
@@ -80,6 +88,7 @@ class LocalPosixEelApiImpl(private val nioFs: FileSystem = FileSystems.getDefaul
   }
 
   override val fs: LocalEelFileSystemPosixApi = object : PosixNioBasedEelFileSystemApi(nioFs, userInfo) {
+    override val pathOs: EelPath.OS = EelPath.OS.UNIX
     override val descriptor: EelDescriptor get() = LocalEelDescriptor
 
     override suspend fun createTemporaryDirectory(

platform/eel/api-dump-experimental.txt

@@ -393,13 +393,6 @@ f:com.intellij.platform.eel.channels.EelSendChannelKt
 - a:toString():java.lang.String
 *f:com.intellij.platform.eel.path.EelPath$Companion
 - f:parse(java.lang.String,com.intellij.platform.eel.EelDescriptor):com.intellij.platform.eel.path.EelPath
-*e:com.intellij.platform.eel.path.EelPath$OS
-- java.lang.Enum
-- sf:UNIX:com.intellij.platform.eel.path.EelPath$OS
-- sf:WINDOWS:com.intellij.platform.eel.path.EelPath$OS
-- s:getEntries():kotlin.enums.EnumEntries
-- s:valueOf(java.lang.String):com.intellij.platform.eel.path.EelPath$OS
-- s:values():com.intellij.platform.eel.path.EelPath$OS[]
 *f:com.intellij.platform.eel.path.EelPathException
 - java.lang.RuntimeException
 - <init>(java.lang.String,java.lang.String):V

platform/eel/src/com/intellij/platform/eel/EelApi.kt

@@ -18,7 +18,6 @@ interface EelApi {
   @get:ApiStatus.Experimental
   val descriptor: EelDescriptor
 
-  // TODO: should it be extension property?
   val platform: EelPlatform
 
   /** Docs: [EelFileSystemApi] */

platform/eel/src/com/intellij/platform/eel/EelDescriptor.kt

@@ -51,7 +51,7 @@ interface EelDescriptorWithoutNativeFileChooserSupport : EelDescriptor
  */
 @ApiStatus.Experimental
 interface EelDescriptor {
-  @Deprecated("Use platform instead", ReplaceWith("platform"))
+  @Deprecated("Use osFamily instead", ReplaceWith("platform"))
   @get:ApiStatus.Internal
   val operatingSystem: OS
     get() = when (osFamily) {

platform/eel/src/com/intellij/platform/eel/fs/EelFileSystemApi.kt

@@ -9,6 +9,14 @@ import org.jetbrains.annotations.ApiStatus
 import org.jetbrains.annotations.CheckReturnValue
 import java.nio.ByteBuffer
 
+@get:ApiStatus.Internal
+val EelFileSystemApi.pathOs: EelPath.OS
+  get() = when (this) {
+    is EelFileSystemPosixApi -> EelPath.OS.UNIX
+    is EelFileSystemWindowsApi -> EelPath.OS.WINDOWS
+    else -> throw UnsupportedOperationException("Unsupported OS: ${this::class.java}")
+  }
+
 @get:ApiStatus.Internal
 val EelFileSystemApi.pathSeparator: String
   get() = when (this) {

platform/eel/src/com/intellij/platform/eel/path/ArrayListEelAbsolutePath.kt

@@ -3,7 +3,6 @@ package com.intellij.platform.eel.path
 
 import com.intellij.platform.eel.EelDescriptor
 import com.intellij.platform.eel.EelOsFamily
-import com.intellij.platform.eel.directorySeparators
 
 internal class ArrayListEelAbsolutePath private constructor(
   override val descriptor: EelDescriptor,
@@ -53,7 +52,7 @@ internal class ArrayListEelAbsolutePath private constructor(
   }
 
   override fun resolve(other: String): EelPath {
-    val delimiters = this.platform.directorySeparators
+    val delimiters = this.os.directorySeparators
     val otherParts = other.split(*delimiters).filter(String::isNotEmpty)
     for (name in otherParts) {
       if (name.isNotEmpty()) {
@@ -117,6 +116,12 @@ internal class ArrayListEelAbsolutePath private constructor(
     return nameCount - other.nameCount
   }
 
+  override val os: EelPath.OS
+    get() = when (this._root) {
+      Root.Unix -> EelPath.OS.UNIX
+      is Root.Windows -> EelPath.OS.WINDOWS
+    }
+
   override fun equals(other: Any?): Boolean =
     other is EelPath &&
     nameCount == other.nameCount &&

platform/eel/src/com/intellij/platform/eel/path/EelPath.kt

@@ -3,6 +3,8 @@ package com.intellij.platform.eel.path
 
 import com.intellij.platform.eel.EelDescriptor
 import com.intellij.platform.eel.EelOsFamily
+import com.intellij.platform.eel.EelPlatform
+import com.intellij.platform.eel.path.EelPath.OS
 import org.jetbrains.annotations.ApiStatus
 
 @get:ApiStatus.Internal
@@ -135,6 +137,17 @@ sealed interface EelPath {
   /** See [java.nio.file.Path.endsWith] */
   fun endsWith(suffix: List<String>): Boolean
 
+  /**
+   * Returns [EelPath.OS] that corresponds to this path.
+   *
+   *  ```kotlin
+   *  EelPath.parse("/abc/").os == EelPath.OS.UNIX
+   *  EelPath.parse("C:\\abc\").os == EelPath.OS.WINDOWS
+   *  ```
+   */
+  @get:ApiStatus.Internal
+  val os: OS
+
   /**
    * ```kotlin
    * EelPath.parse("/abc", OS.UNIX).getChild("..") == EelPath.parse("abc/..", false)
@@ -154,7 +167,7 @@ sealed interface EelPath {
    */
   override fun toString(): String
 
-  @Deprecated("Use EelPlatform instead, will be removed soon")
+  @ApiStatus.Internal
   enum class OS {
     WINDOWS, UNIX
   }
@@ -165,3 +178,27 @@ operator fun EelPath.div(part: String): EelPath = resolve(part)
 
 @ApiStatus.Experimental
 class EelPathException(val raw: String, val reason: String) : RuntimeException("`$raw`: $reason")
+
+@get:ApiStatus.Internal
+val OS.pathSeparator: String
+  get() = when (this) {
+    OS.UNIX -> ":"
+    OS.WINDOWS -> ";"
+  }
+
+@get:ApiStatus.Internal
+val EelPlatform.pathOs: OS
+  get() = when (this) {
+    is EelPlatform.Posix -> OS.UNIX
+    is EelPlatform.Windows -> OS.WINDOWS
+  }
+
+private val UNIX_DIRECTORY_SEPARATORS = charArrayOf('/')
+private val WINDOWS_DIRECTORY_SEPARATORS = charArrayOf('/', '\\')
+
+@get:ApiStatus.Internal
+val OS.directorySeparators: CharArray
+  get() = when (this) {
+    OS.UNIX -> UNIX_DIRECTORY_SEPARATORS
+    OS.WINDOWS -> WINDOWS_DIRECTORY_SEPARATORS
+  }

platform/ijent/impl/src/com/intellij/platform/ijent/community/impl/nio/IjentNioFileSystem.kt

@@ -1,4 +1,4 @@
-// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.platform.ijent.community.impl.nio
 
 import com.intellij.platform.eel.directorySeparators
@@ -67,6 +67,10 @@ class IjentNioFileSystem internal constructor(
     }
 
   override fun getPath(first: String, vararg more: String): IjentNioPath {
+    val os = when (ijentFs) {
+      is IjentFileSystemPosixApi -> EelPath.OS.UNIX
+      is IjentFileSystemWindowsApi -> EelPath.OS.WINDOWS
+    }
     return try {
       more.fold(EelPath.parse(first, ijentFs.descriptor)) { path, newPart -> path.resolve(newPart) }.toNioPath()
     }

platform/ijent/impl/src/com/intellij/platform/ijent/community/impl/nio/IjentNioPath.kt

@@ -2,10 +2,8 @@
 package com.intellij.platform.ijent.community.impl.nio
 
 import com.intellij.platform.core.nio.fs.BasicFileAttributesHolder2
-import com.intellij.platform.eel.EelOsFamily
 import com.intellij.platform.eel.path.EelPath
 import com.intellij.platform.eel.path.EelPathException
-import com.intellij.platform.eel.path.platform
 import com.intellij.platform.eel.provider.utils.getOrThrowFileSystemException
 import org.jetbrains.annotations.ApiStatus
 import java.net.URI
@@ -156,9 +154,9 @@ internal class AbsoluteIjentNioPath(val eelPath: EelPath, nioFs: IjentNioFileSys
   }
 
   override fun toUri(): URI {
-    val prefix = when (eelPath.platform) {
-      EelOsFamily.Windows -> "/" + eelPath.root.toString().replace('\\', '/')
-      EelOsFamily.Posix -> null
+    val prefix = when (eelPath.os) {
+      EelPath.OS.WINDOWS -> "/" + eelPath.root.toString().replace('\\', '/')
+      EelPath.OS.UNIX -> null
     }
     val allParts = listOfNotNull(prefix) + eelPath.parts
     return allParts.fold(nioFs.uri, URI::resolve)

platform/ijent/src/com/intellij/platform/ijent/EelPlatformEx.kt

@@ -1,4 +1,4 @@
-// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.platform.ijent
 
 import com.intellij.platform.eel.EelPlatform

platform/ijent/src/com/intellij/platform/ijent/spi/IjentDeployingOverShellProcessStrategy.kt

@@ -1,4 +1,4 @@
-// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.platform.ijent.spi
 
 import com.intellij.execution.CommandLineUtil.posixQuote
@@ -58,16 +58,12 @@ abstract class IjentDeployingOverShellProcessStrategy(scope: CoroutineScope) : I
     context
   }
 
-  private val myTargetPlatform = scope.async(start = CoroutineStart.LAZY) {
-    myContext.await().execCommand {
+  override suspend fun getTargetPlatform(): EelPlatform.Posix {
+    return myContext.await().execCommand {
       getTargetPlatform()
     }
   }
 
-  override suspend fun getTargetPlatform(): EelPlatform.Posix {
-    return myTargetPlatform.await()
-  }
-
   final override suspend fun createProcess(binaryPath: String): IjentSessionMediator {
     return myContext.await().execCommand {
       execIjent(binaryPath)

platform/lang-impl/testSources/com/intellij/openapi/projectRoots/ProjectJdkEelTest.kt

@@ -6,7 +6,6 @@ import com.intellij.openapi.application.edtWriteAction
 import com.intellij.openapi.roots.ui.configuration.SdkTestCase.TestSdkGenerator.SdkInfo
 import com.intellij.openapi.roots.ui.configuration.projectRoot.ProjectSdksModel
 import com.intellij.openapi.roots.ui.configuration.testSdkFixture
-import com.intellij.platform.eel.EelPlatform
 import com.intellij.platform.eel.path.EelPath
 import com.intellij.platform.eel.provider.utils.EelPathUtils
 import com.intellij.platform.testFramework.junit5.eel.fixture.eelFixture
@@ -26,7 +25,7 @@ import java.nio.file.Files
 
 @TestApplication
 class ProjectJdkEelTest {
-  val eel = eelFixture(EelPlatform.Linux(EelPlatform.Arch.Unknown))
+  val eel = eelFixture(EelPath.OS.UNIX)
 
   val localProject = projectFixture(openAfterCreation = true)
 

platform/platform-impl/eel/src/com/intellij/platform/ide/impl/wsl/ijent/nio/toggle/IjentWslNioFsToggleStrategy.kt

@@ -5,10 +5,8 @@ import com.intellij.execution.wsl.WSLDistribution
 import com.intellij.execution.wsl.WslDistributionManager
 import com.intellij.execution.wsl.WslIjentManager
 import com.intellij.openapi.diagnostic.logger
-import com.intellij.openapi.progress.runBlockingMaybeCancellable
 import com.intellij.platform.eel.provider.EelNioBridgeService
 import com.intellij.platform.ide.impl.wsl.ijent.nio.IjentWslNioFileSystemProvider
-import com.intellij.platform.ijent.IjentPosixApi
 import com.intellij.platform.ijent.community.impl.IjentFailSafeFileSystemPosixApi
 import com.intellij.platform.ijent.community.impl.nio.IjentNioFileSystemProvider
 import com.intellij.platform.ijent.community.impl.nio.telemetry.TracingFileSystemProvider
@@ -22,19 +20,14 @@ import java.net.URI
 import java.nio.file.FileSystem
 import java.nio.file.FileSystemAlreadyExistsException
 import java.nio.file.spi.FileSystemProvider
-import java.util.concurrent.ConcurrentHashMap
 import java.util.function.BiConsumer
 
-private suspend fun WSLDistribution.getIjent(): IjentPosixApi {
-  return WslIjentManager.instanceAsync().getIjentApi(this, null, false)
-}
-
 @ApiStatus.Internal
 @VisibleForTesting
 class IjentWslNioFsToggleStrategy(
   private val coroutineScope: CoroutineScope,
 ) {
-  internal val enabledInDistros: MutableMap<WSLDistribution, WslEelDescriptor> = ConcurrentHashMap()
+  internal val enabledInDistros: MutableSet<WSLDistribution> = ContainerUtil.newConcurrentSet()
 
   private val providersCache = ContainerUtil.createConcurrentWeakMap<String, IjentWslNioFileSystemProvider>()
 
@@ -67,27 +60,23 @@ class IjentWslNioFsToggleStrategy(
   }
 
   private fun handleWslDistributionAddition(distro: WSLDistribution) {
+    enabledInDistros += distro
     switchToIjentFs(distro)
   }
 
   private fun handleWslDistributionDeletion(distro: WSLDistribution) {
-    val descriptor = enabledInDistros.remove(distro)
-
-    if (descriptor != null) {
-      recomputeEel(descriptor) { _, actualFs ->
+    enabledInDistros -= distro
+    recomputeEel(distro) { _, actualFs ->
       actualFs
     }
   }
-  }
 
   fun switchToIjentFs(distro: WSLDistribution) {
     val ijentFsProvider = TracingFileSystemProvider(IjentNioFileSystemProvider.getInstance())
-    val descriptor = runBlockingMaybeCancellable { distro.getIjent() }.descriptor as WslEelDescriptor
-
-    enabledInDistros[distro] = descriptor
-
     try {
-      val ijentFs = IjentFailSafeFileSystemPosixApi(coroutineScope) { distro.getIjent() }
+      val ijentFs = IjentFailSafeFileSystemPosixApi(coroutineScope) {
+        WslIjentManager.instanceAsync().getIjentApi(distro, null, false)
+      }
       ijentFsProvider.newFileSystem(
         URI("ijent", "wsl", "/${distro.id}", null, null),
         IjentNioFileSystemProvider.newFileSystemMap(ijentFs),
@@ -97,7 +86,7 @@ class IjentWslNioFsToggleStrategy(
       // Nothing.
     }
 
-    recomputeEel(descriptor) { underlyingProvider, _ ->
+    recomputeEel(distro) { underlyingProvider, _ ->
       val fileSystemProvider = providersCache.computeIfAbsent(distro.id) {
         IjentWslNioFileSystemProvider(
           wslDistribution = distro,
@@ -111,9 +100,9 @@ class IjentWslNioFsToggleStrategy(
     }
   }
 
-  fun switchToTracingWsl9pFs(descriptor: WslEelDescriptor) {
-    recomputeEel(descriptor) { underlyingProvider, previousFs ->
-      LOG.info("Switching $descriptor to the original file system but with tracing")
+  fun switchToTracingWsl9pFs(distro: WSLDistribution) {
+    recomputeEel(distro) { underlyingProvider, previousFs ->
+      LOG.info("Switching $distro to the original file system but with tracing")
 
       try {
         previousFs?.close()
@@ -129,11 +118,14 @@ class IjentWslNioFsToggleStrategy(
   fun unregisterAll() {
     val service = EelNioBridgeService.getInstanceSync()
 
-    enabledInDistros.entries.forEachGuaranteed { (_, descriptor) ->
-      service.unregister(descriptor)
+    val distros = mutableListOf<WSLDistribution>()
+    enabledInDistros.removeIf {
+      distros += it
+      true
+    }
+    for (distro in distros) {
+      service.unregister(WslEelDescriptor(distro))
     }
-
-    enabledInDistros.clear()
   }
 }
 
@@ -152,12 +144,13 @@ private val WSLDistribution.roots: Set<String>
   }
 
 private fun recomputeEel(
-  descriptor: WslEelDescriptor,
+  distro: WSLDistribution,
   action: (underlyingProvider: FileSystemProvider, previousFs: FileSystem?) -> FileSystem?,
 ) {
   val service = EelNioBridgeService.getInstanceSync()
+  val descriptor = WslEelDescriptor(distro)
 
-  descriptor.distribution.roots.forEachGuaranteed { localRoot ->
-    service.register(localRoot, descriptor, descriptor.distribution.id, false, false, action)
+  distro.roots.forEachGuaranteed { localRoot ->
+    service.register(localRoot, descriptor, distro.id, false, false, action)
   }
 }

platform/platform-impl/eel/src/com/intellij/platform/ide/impl/wsl/ijent/nio/toggle/IjentWslNioFsToggler.kt

@@ -48,14 +48,15 @@ class IjentWslNioFsToggler(private val coroutineScope: CoroutineScope) {
   fun switchToIjentFs(distro: WSLDistribution) {
     logErrorIfNotWindows()
     strategy ?: error("Not available")
+    strategy.enabledInDistros.add(distro)
     strategy.switchToIjentFs(distro)
   }
 
   @TestOnly
-  fun switchToTracingWsl9pFs(descriptor: WslEelDescriptor) {
+  fun switchToTracingWsl9pFs(distro: WSLDistribution) {
     logErrorIfNotWindows()
     strategy ?: error("Not available")
-    strategy.switchToTracingWsl9pFs(descriptor)
+    strategy.switchToTracingWsl9pFs(distro)
   }
 
   @TestOnly

platform/testFramework/junit5/eel/src/fixture/fixtures.kt

@@ -3,7 +3,7 @@ package com.intellij.platform.testFramework.junit5.eel.fixture
 
 import com.intellij.platform.eel.EelApi
 import com.intellij.platform.eel.EelDescriptor
-import com.intellij.platform.eel.EelPlatform
+import com.intellij.platform.eel.EelOsFamily
 import com.intellij.platform.eel.path.EelPath
 import com.intellij.platform.testFramework.junit5.eel.impl.currentOs
 import com.intellij.platform.testFramework.junit5.eel.impl.eelInitializer
@@ -39,7 +39,11 @@ interface IsolatedFileSystem {
  * The local file system would not be able to recognize these paths, so you can test whether your feature is eel-agnostic.
  */
 @TestOnly
-fun eelFixture(os: EelPlatform = currentOs): TestFixture<IsolatedFileSystem> {
+fun eelFixture(os: EelPath.OS = currentOs): TestFixture<IsolatedFileSystem> {
+  val os = when (os) {
+    EelPath.OS.WINDOWS -> EelOsFamily.Windows
+    EelPath.OS.UNIX -> EelOsFamily.Posix
+  }
   return testFixture("eel-test-fixture", eelInitializer(os))
 }
 

platform/testFramework/junit5/eel/src/impl/nio/EelUnitTestFileSystem.kt

@@ -1,19 +1,14 @@
-// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.platform.testFramework.junit5.eel.impl.nio
 
 import com.intellij.openapi.util.SystemInfo
-import com.intellij.platform.eel.EelPlatform
-import com.intellij.platform.eel.path.EelPath
+import com.intellij.platform.eel.EelOsFamily
 import java.io.File
-import java.nio.file.FileStore
-import java.nio.file.FileSystem
-import java.nio.file.Path
-import java.nio.file.PathMatcher
-import java.nio.file.WatchService
+import java.nio.file.*
 import java.nio.file.attribute.UserPrincipalLookupService
 import java.nio.file.spi.FileSystemProvider
 
-internal class EelUnitTestFileSystem(val provider: FileSystemProvider, val os: EelPlatform, val rootDirectory: Path, val fakeLocalRoot: String) : FileSystem() {
+internal class EelUnitTestFileSystem(val provider: FileSystemProvider, val os: EelOsFamily, val rootDirectory: Path, val fakeLocalRoot: String) : FileSystem() {
   val root: EelUnitTestPath = EelUnitTestPath(this, rootDirectory)
 
   override fun provider(): FileSystemProvider {

platform/testFramework/junit5/eel/src/impl/util.kt

@@ -5,11 +5,9 @@ package com.intellij.platform.testFramework.junit5.eel.impl
 
 import com.intellij.openapi.util.SystemInfo
 import com.intellij.platform.core.nio.fs.MultiRoutingFileSystem
-import com.intellij.platform.eel.EelApi
-import com.intellij.platform.eel.EelDescriptor
-import com.intellij.platform.eel.EelPlatform
+import com.intellij.platform.eel.*
 import com.intellij.platform.eel.fs.createTemporaryDirectory
-import com.intellij.platform.eel.getOrThrow
+import com.intellij.platform.eel.path.EelPath
 import com.intellij.platform.eel.provider.EelNioBridgeService
 import com.intellij.platform.eel.provider.asNioPath
 import com.intellij.platform.testFramework.junit5.eel.fixture.IsolatedFileSystem
@@ -28,31 +26,26 @@ import kotlin.io.path.name
 
 internal const val FAKE_WINDOWS_ROOT = "\\\\dummy-ij-root\\test-eel\\"
 
-private val EelPlatform.name: String get() = when (this) {
-  is EelPlatform.Posix -> "posix"
-  is EelPlatform.Windows -> "windows"
-}
-
-internal val currentOs: EelPlatform
+internal val currentOs: EelPath.OS
   get() = if (SystemInfo.isWindows) {
-    EelPlatform.Windows(EelPlatform.Arch.Unknown)
+    EelPath.OS.WINDOWS
   }
   else {
-    EelPlatform.Linux(EelPlatform.Arch.Unknown)
+    EelPath.OS.UNIX
   }
 
-internal fun eelApiByOs(fileSystem: EelUnitTestFileSystem, descriptor: EelTestDescriptor, os: EelPlatform): EelApi {
+internal fun eelApiByOs(fileSystem: EelUnitTestFileSystem, descriptor: EelTestDescriptor, os: EelOsFamily): EelApi {
   return when (os) {
-    is EelPlatform.Posix -> EelTestPosixApi(descriptor, fileSystem, fileSystem.fakeLocalRoot)
-    is EelPlatform.Windows -> EelTestWindowsApi(descriptor, fileSystem, fileSystem.fakeLocalRoot)
+    EelOsFamily.Posix  -> EelTestPosixApi(descriptor, fileSystem, fileSystem.fakeLocalRoot)
+    EelOsFamily.Windows -> EelTestWindowsApi(descriptor, fileSystem, fileSystem.fakeLocalRoot)
   }
 }
 
 internal data class IsolatedFileSystemImpl(override val storageRoot: Path, override val eelDescriptor: EelDescriptor, override val eelApi: EelApi) : IsolatedFileSystem
 
-internal fun eelInitializer(os: EelPlatform): TestFixtureInitializer<IsolatedFileSystem> = TestFixtureInitializer { initialized ->
+internal fun eelInitializer(os: EelOsFamily): TestFixtureInitializer<IsolatedFileSystem> = TestFixtureInitializer { initialized ->
   checkMultiRoutingFileSystem()
-  val meaningfulDirName = "eel-fixture-${os.name}"
+  val meaningfulDirName = "eel-fixture-${os.name.lowercase()}"
   val directory = Files.createTempDirectory(meaningfulDirName)
 
   val fakeRoot = if (SystemInfo.isUnix) {
@@ -67,8 +60,8 @@ internal fun eelInitializer(os: EelPlatform): TestFixtureInitializer<IsolatedFil
   val service = EelNioBridgeService.getInstanceSync()
   val fakeLocalFileSystem = EelUnitTestFileSystem(EelUnitTestFileSystemProvider(defaultProvider), os, directory, fakeRoot)
   val apiRef = AtomicReference<EelApi>(null)
-  val descriptor = EelTestDescriptor(Ksuid.generate().toString(), os.osFamily, apiRef::get)
-  service.register(fakeRoot, descriptor, descriptor.id, true, (os is EelPlatform.Windows)) { _, _ ->
+  val descriptor = EelTestDescriptor(Ksuid.generate().toString(), os, apiRef::get)
+  service.register(fakeRoot, descriptor, descriptor.id, true, (os.isWindows)) { _, _ ->
     fakeLocalFileSystem
   }
   val eelApi = eelApiByOs(fakeLocalFileSystem, descriptor, os)

platform/testFramework/junit5/eel/test/showcase/EelFsShowcase.kt

@@ -1,15 +1,14 @@
-// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.platform.testFramework.junit5.eel.showcase
 
 import com.intellij.openapi.util.io.OSAgnosticPathUtil
-import com.intellij.platform.eel.EelPlatform
 import com.intellij.platform.eel.path.EelPath
 import com.intellij.platform.eel.provider.asEelPath
 import com.intellij.platform.eel.provider.asNioPath
 import com.intellij.platform.eel.provider.utils.EelPathUtils
-import com.intellij.testFramework.junit5.TestApplication
 import com.intellij.platform.testFramework.junit5.eel.fixture.IsolatedFileSystem
 import com.intellij.platform.testFramework.junit5.eel.fixture.eelFixture
+import com.intellij.testFramework.junit5.TestApplication
 import com.intellij.testFramework.junit5.fixture.TestFixture
 import org.junit.jupiter.api.Assertions
 import org.junit.jupiter.api.Test
@@ -20,13 +19,13 @@ import java.nio.file.Path
 @TestApplication
 class EelFsShowcase {
 
-  val fsAndEelUnix: TestFixture<IsolatedFileSystem> = eelFixture(EelPlatform.Linux(EelPlatform.Arch.Unknown))
+  val fsAndEelUnix: TestFixture<IsolatedFileSystem> = eelFixture(EelPath.OS.UNIX)
 
-  val fsAndEelWindows: TestFixture<IsolatedFileSystem> = eelFixture(EelPlatform.Windows(EelPlatform.Arch.Unknown))
+  val fsAndEelWindows: TestFixture<IsolatedFileSystem> = eelFixture(EelPath.OS.WINDOWS)
 
-  fun EelPlatform.osDependentFixture(): TestFixture<IsolatedFileSystem> = when (this) {
-    is EelPlatform.Windows -> fsAndEelWindows
-    is EelPlatform.Posix -> fsAndEelUnix
+  fun EelPath.OS.osDependentFixture(): TestFixture<IsolatedFileSystem> = when (this) {
+    EelPath.OS.WINDOWS -> fsAndEelWindows
+    EelPath.OS.UNIX -> fsAndEelUnix
   }
 
   @Test
@@ -60,17 +59,16 @@ class EelFsShowcase {
     Assertions.assertEquals(eelNio, eelNioEel)
   }
 
-  @Test
-  fun `uri validity`() {
-    for (eel in listOf(fsAndEelUnix, fsAndEelWindows)) {
-      val root = eel.get().storageRoot
+  @ParameterizedTest
+  @EnumSource(EelPath.OS::class)
+  fun `uri validity`(os: EelPath.OS) {
+    val root = os.osDependentFixture().get().storageRoot
     val path = root.resolve("a/b/c/d/e")
     val uri = EelPathUtils.getUriLocalToEel(path)
     Assertions.assertEquals("file", uri.scheme)
     Assertions.assertNull(uri.authority)
     Assertions.assertTrue(uri.path.contains("a/b/c/d/e"))
   }
-  }
 
   @Test
   fun `windows path is separator agnostic`() {

platform/testFramework/junit5/eel/test/showcase/EelProjectShowcase.kt

@@ -1,13 +1,12 @@
-// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.platform.testFramework.junit5.eel.showcase
 
-import com.intellij.platform.eel.EelPlatform
 import com.intellij.platform.eel.path.EelPath
 import com.intellij.platform.eel.provider.asEelPath
 import com.intellij.platform.eel.provider.utils.EelPathUtils
-import com.intellij.testFramework.junit5.TestApplication
 import com.intellij.platform.testFramework.junit5.eel.fixture.eelFixture
 import com.intellij.platform.testFramework.junit5.eel.fixture.tempDirFixture
+import com.intellij.testFramework.junit5.TestApplication
 import com.intellij.testFramework.junit5.fixture.projectFixture
 import org.junit.jupiter.api.Assertions
 import org.junit.jupiter.api.Test
@@ -15,7 +14,7 @@ import java.nio.file.Path
 
 @TestApplication
 class EelProjectShowcase {
-  val eel = eelFixture(EelPlatform.Linux(EelPlatform.Arch.Unknown))
+  val eel = eelFixture(EelPath.OS.UNIX)
   val tempDir = eel.tempDirFixture()
   val project = projectFixture(tempDir, openAfterCreation = true)
 

platform/workspace/jps/tests/testSrc/com/intellij/workspaceModel/ide/GlobalWorkspaceModelEelTest.kt

@@ -6,7 +6,6 @@ import com.intellij.openapi.application.edtWriteAction
 import com.intellij.openapi.components.service
 import com.intellij.openapi.util.registry.Registry
 import com.intellij.platform.backend.workspace.GlobalWorkspaceModelCache
-import com.intellij.platform.eel.EelPlatform
 import com.intellij.platform.eel.path.EelPath
 import com.intellij.platform.eel.provider.getEelDescriptor
 import com.intellij.platform.testFramework.junit5.eel.fixture.eelFixture
@@ -26,7 +25,7 @@ import org.junit.jupiter.api.Test
 
 @TestApplication
 class GlobalWorkspaceModelEelTest {
-  val eel = eelFixture(EelPlatform.Linux(EelPlatform.Arch.Unknown))
+  val eel = eelFixture(EelPath.OS.UNIX)
 
   val eelTempDir = eel.tempDirFixture()
   val eelProject = projectFixture(eelTempDir)

python/services/internal-impl/src/com/intellij/python/community/services/internal/impl/VanillaPythonWithLanguageLevelImpl.kt

@@ -1,7 +1,8 @@
 // Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.python.community.services.internal.impl
 
-import com.intellij.platform.eel.EelPlatform
+import com.intellij.platform.eel.fs.pathOs
+import com.intellij.platform.eel.path.EelPath
 import com.intellij.platform.eel.provider.asNioPath
 import com.intellij.platform.eel.provider.getEelDescriptor
 import com.intellij.python.community.execService.python.validatePythonAndGetVersion
@@ -75,9 +76,9 @@ class VanillaPythonWithLanguageLevelImpl internal constructor(
   override suspend fun getReadableName(): @Nls String {
     val eelApi = pythonBinary.getEelDescriptor().toEelApi()
     val home = eelApi.userInfo.home.asNioPath()
-    val separator = when (eelApi.platform) {
-      is EelPlatform.Windows -> "\\"
-      is EelPlatform.Posix -> "/"
+    val separator = when (eelApi.fs.pathOs) {
+      EelPath.OS.WINDOWS -> "\\"
+      EelPath.OS.UNIX -> "/"
     }
     val pythonString = (if (pythonBinary.startsWith(home)) "~$separator" + pythonBinary.relativeTo(home).pathString
     else pythonBinary.pathString)