Fixed relative path detection on Windows, split parent path test to platform specific tests as NodeJS handles UNC path differently

Author: fzhinkin

core/common/test/files/SmokeFileTestWindows.kt

@@ -15,8 +15,7 @@ class SmokeFileTestWindows {
         assertTrue(Path("C:\\").isAbsolute)
         assertTrue(Path("C:/").isAbsolute)
         assertTrue(Path("C:/../").isAbsolute)
-        // Well, it's a relative path, but Win32's PathIsRelative don't think so.
-        assertTrue(Path("C:file").isAbsolute)
+        assertFalse(Path("C:file").isAbsolute)
         assertFalse(Path("bla\\bla\\bla").isAbsolute)
         assertTrue(Path("\\\\server\\share").isAbsolute)
     }
@@ -26,7 +25,6 @@ class SmokeFileTestWindows {
         if (!isWindows) return
         assertNull(Path("C:\\").parent)
         assertNull(Path("a\\b").parent?.parent)
-        assertEquals(Path("\\\\server"), Path("\\\\server\\share").parent)
         assertEquals(Path("C:\\"), Path("C:\\Program Files").parent)
         assertEquals(Path("C:\\Program Files"), Path("C:\\Program Files/Java").parent)
     }
@@ -38,7 +36,9 @@ class SmokeFileTestWindows {
         assertEquals("C:\\", Path("C:\\").toString())
         assertEquals("C:\\", Path("C:\\\\").toString())
         assertEquals("\\\\", Path("\\\\").toString())
-        assertEquals("//", Path("//").toString())
         assertEquals(".\\a", Path(".\\a\\//\\//\\\\////").toString())
+
+        // this path could be transformed to use canonical separator on JVM
+        assertEquals(Path("//").toString(), Path("//").toString())
     }
 }

core/js/test/files/SmokeFileTestWindowsJS.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2010-2024 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE.txt file.
+ */
+
+package kotlinx.io.files
+
+import kotlinx.io.isWindows
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
+
+class SmokeFileTestWindowMinGW  {
+    @Test
+    fun uncParent() {
+        if (!isWindows) return
+        // NodeJS, correctly, assume that it's a root path, that's where behavior diverge
+        assertNull(Path("\\\\server\\share").parent)
+        assertEquals(Path("\\\\server\\share"), Path("\\\\server\\share\\dir").parent)
+    }
+}

core/jvm/test/files/SmokeFileTestWindowsJVM.kt

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2010-2024 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE.txt file.
+ */
+
+package kotlinx.io.files
+
+import kotlinx.io.isWindows
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class SmokeFileTestWindowsJVM {
+    @Test
+    fun uncParent() {
+        if (!isWindows) return
+        assertEquals(Path("\\\\server"), Path("\\\\server\\share").parent)
+        assertEquals(Path("\\\\server\\share"), Path("\\\\server\\share\\dir").parent)
+    }
+}

core/mingw/src/files/FileSystemMingw.kt

@@ -38,6 +38,11 @@ internal actual fun basenameImpl(path: String): String {
 
 internal actual fun isAbsoluteImpl(path: String): Boolean {
     if (path.startsWith(SystemPathSeparator)) return true
+    if (path.length > 1 && path[1] == ':') {
+        if (path.length == 1) return false
+        val next = path[2]
+        return next == WindowsPathSeparator || next == SystemPathSeparator
+    }
     return PathIsRelativeA(path) == 0
 }
 

core/mingw/test/files/SmokeFileTestWindowsMinGW.kt

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2010-2024 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE.txt file.
+ */
+
+package kotlinx.io.files
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class SmokeFileTestWindowsMinGW  {
+    @Test
+    fun uncParent() {
+        assertEquals(Path("\\\\server"), Path("\\\\server\\share").parent)
+        assertEquals(Path("\\\\server\\share"), Path("\\\\server\\share\\dir").parent)
+    }
+}