Resolve path slashes on File instantiation

README.md

@@ -19,14 +19,17 @@
 
 A very simple `File` API for Kotlin Multiplatform. It gets the job done.
 
-For `Jvm`, `File` is `typealias` to `java.io.File`
+For `Jvm`, `File` is `typealias` to `java.io.File`. `File` for `nonJvm` is
+operationally equivalent to `Jvm` for consistency across platforms.
 
 ```kotlin
 import io.matthewnelson.kmp.file.*
 
 fun commonMain(f: File) {
-    SYSTEM_PATH_SEPARATOR
-    SYSTEM_TEMP_DIRECTORY
+    // System path separator character (`/` or `\`)
+    SysPathSep
+    // System temporary directory
+    SysTempDir
 
     f.isAbsolute()
     f.exists()
@@ -44,9 +47,13 @@ fun commonMain(f: File) {
     f.canonicalPath()
     f.canonicalFile()
 
+    // equivalent to File("/some/path")
+    val file = "/some/path".toFile()
+
     // resolve child paths
-    val child = f.resolve("child")
-    child.resolve(f)
+    val child = file.resolve("child")
+    println(child.path) // >> `/some/path/child`
+    println(child.resolve(file).path) // >> `/some/path` (file is rooted)
 
     // normalized File (e.g. removal of . and ..)
     f.normalize()

library/file/api/file.api

@@ -14,12 +14,11 @@ public final class io/matthewnelson/kmp/file/File {
 	public static final fun path (Ljava/io/File;)Ljava/lang/String;
 	public static final fun resolve (Ljava/io/File;Ljava/lang/String;)Ljava/io/File;
 	public static final fun toFile (Ljava/lang/String;)Ljava/io/File;
-	public static final fun toFile (Ljava/lang/String;Ljava/lang/String;)Ljava/io/File;
 }
 
 public final class io/matthewnelson/kmp/file/FileJvm {
-	public static final field SYSTEM_PATH_SEPARATOR C
-	public static final field SYSTEM_TEMP_DIRECTORY Ljava/io/File;
+	public static final field SysPathSep C
+	public static final field SysTempDir Ljava/io/File;
 	public static final fun normalize (Ljava/io/File;)Ljava/io/File;
 	public static final fun readBytes (Ljava/io/File;)[B
 	public static final fun readUtf8 (Ljava/io/File;)Ljava/lang/String;

library/file/src/commonMain/kotlin/io/matthewnelson/kmp/file/File.kt

@@ -21,24 +21,46 @@ package io.matthewnelson.kmp.file
 import kotlin.jvm.JvmName
 
 /**
- * Most all systems it will be `/`, but for Windows because it is
- * special it will be `\`
+ * The operating system's path separator character
  * */
-public expect val SYSTEM_PATH_SEPARATOR: Char
+public expect val SysPathSep: Char
 
 /**
  * The system temporary directory
  * */
-public expect val SYSTEM_TEMP_DIRECTORY: File
+public expect val SysTempDir: File
+
+public fun String.toFile(): File = File(this)
 
 /**
  * A File
  * */
-public expect class File {
-
-    public constructor(pathname: String)
-    public constructor(parent: String, child: String)
-    public constructor(parent: File, child: String)
+public expect class File(pathname: String) {
+
+    // Not exposing any secondary constructors because
+    // Jvm has undocumented behavior that cannot be
+    // modified because it's typealias.
+    //
+    // java.io.File's secondary constructors take 2
+    // arguments and concatenate the paths together. If
+    // the first argument is empty though, the result
+    // will always contain the system path separator as
+    // the first character.
+    //
+    // println(File("", "child").path) >> "/child"
+    // println(File(File(""), "child").path) >> "/child"
+    // println(File("", "./child").path) >> "/./child"
+    //
+    // So for Unix, the "child" argument now magically
+    // becomes absolute instead of relative to the current
+    // working directory.
+    //
+    // This could be dangerous if someone were to do:
+    //
+    // File(fileFromSomewhereElse, "child")
+    //
+    // thinking that it would simply be appended to the
+    // parent.
 
     public fun isAbsolute(): Boolean
 
@@ -49,7 +71,7 @@ public expect class File {
 
     // use .name
     internal fun getName(): String
-    // use .parent
+    // use .parentPath
     internal fun getParent(): String?
     // use .parentFile
     internal fun getParentFile(): File?
@@ -69,9 +91,6 @@ public expect class File {
     internal fun getCanonicalFile(): File
 }
 
-public fun String.toFile(): File = File(this)
-public fun String.toFile(child: String): File = File(this, child)
-
 @get:JvmName("name")
 public val File.name: String get() = getName()
 

library/file/src/commonTest/kotlin/io/matthewnelson/kmp/file/AbsoluteUnitTest.kt

@@ -30,6 +30,12 @@ class AbsoluteUnitTest {
         // should be relative for all platforms (even windows)
         assertFalse("C:something".toFile().isAbsolute())
         assertFalse("C:".toFile().isAbsolute())
+        assertFalse("".toFile().isAbsolute())
+        assertFalse(".".toFile().isAbsolute())
+        assertFalse("..".toFile().isAbsolute())
+        assertFalse("./something".toFile().isAbsolute())
+        assertFalse("../something".toFile().isAbsolute())
+        assertFalse("some/path".toFile().isAbsolute())
 
         // TODO: Fix isAbsolute for Nodejs on windows
         if (isNodejs && isWindows) return
@@ -48,8 +54,8 @@ class AbsoluteUnitTest {
         if (isSimulator) return
 
         val rootDir = PROJECT_DIR_PATH.substringBeforeLast(
-            "library"
-                .toFile("file")
+            "library".toFile()
+                .resolve("file")
                 .path
         )
 
@@ -64,6 +70,6 @@ class AbsoluteUnitTest {
         //   `C:\Users\path\to\current\working\dir\C:relative`
         // for a relative path of:
         //   `C:relative`
-        assertTrue(absolute.endsWith("${SYSTEM_PATH_SEPARATOR}relative"))
+        assertTrue(absolute.endsWith("${SysPathSep}relative"))
     }
 }

library/file/src/commonTest/kotlin/io/matthewnelson/kmp/file/CommonTestPlatform.kt

@@ -54,7 +54,7 @@ fun randomName(): String = Random
     .nextBytes(16)
     .encodeToString(Base16)
 
-fun randomTemp(): File = SYSTEM_TEMP_DIRECTORY
+fun randomTemp(): File = SysTempDir
     .resolve(randomName())
 
 fun ByteArray.sha256(): String = SHA256()

library/file/src/commonTest/kotlin/io/matthewnelson/kmp/file/FileUnitTest.kt

@@ -20,24 +20,49 @@ import kotlin.test.assertEquals
 
 class FileUnitTest {
 
-    // TODO: Implement toPath() (Native)
-//    @Test
-//    fun givenFile_whenTrailingSlashes_thenAreRemoved() {
-//        val expected = "expected"
-//
-//        (0..5).forEach { times ->
-//            val file = File(buildString {
-//                append(expected)
-//                repeat(times) { append(SYSTEM_PATH_SEPARATOR) }
-//            })
-//
-//            assertEquals(expected, file.path)
-//        }
-//    }
-
     @Test
     fun givenFile_whenToString_thenPrintsPath() {
         val expected = "something"
         assertEquals(expected, expected.toFile().toString())
     }
+
+    @Test
+    fun givenFile_whenInsaneSlashes_thenAreResolved() {
+        // windows should replace all unix path separators with `\` before
+        assertEquals("relative${SysPathSep}path", "relative////path///".toFile().path)
+        assertEquals("relative${SysPathSep}path${SysPathSep}.", "relative////path///.".toFile().path)
+        assertEquals(".${SysPathSep}..", "./..".toFile().path)
+
+        assertEquals(".", ".".toFile().path)
+        assertEquals("..", "..".toFile().path)
+        assertEquals("...", "...".toFile().path)
+        assertEquals("....", "....".toFile().path)
+
+        if (isWindows) {
+            assertEquals("\\", "\\".toFile().path)
+            assertEquals("\\Relative", "\\Relative".toFile().path)
+            assertEquals("\\Relative", "/Relative".toFile().path)
+            assertEquals("\\Relative\\path", "/Relative/path".toFile().path)
+
+            assertEquals("\\\\", "\\\\".toFile().path)
+            assertEquals("\\\\", "\\\\\\".toFile().path)
+            assertEquals("\\\\", "\\//\\".toFile().path)
+            assertEquals("\\\\Absolute", "\\\\Absolute".toFile().path)
+            assertEquals("\\\\Absolute", "\\\\\\Absolute".toFile().path)
+            assertEquals("\\\\Absolute", "//Absolute".toFile().path)
+            assertEquals("\\\\Absolute", "///Absolute".toFile().path)
+            assertEquals("\\\\Absolute\\path", "///Absolute//path".toFile().path)
+
+            assertEquals("C:\\", "C://".toFile().path)
+            assertEquals("F:", "F:".toFile().path)
+            assertEquals("F:\\", "F:\\\\\\".toFile().path)
+        } else {
+            assertEquals("/", "/".toFile().path)
+            assertEquals("/", "////".toFile().path)
+            assertEquals("\\", "\\".toFile().path)
+            assertEquals("\\\\", "\\\\".toFile().path)
+            assertEquals("/absolute", "//absolute".toFile().path)
+            assertEquals("/absolute\\/path", "///absolute\\////path".toFile().path)
+        }
+    }
 }

library/file/src/commonTest/kotlin/io/matthewnelson/kmp/file/ParentUnitTest.kt

@@ -49,14 +49,13 @@ class ParentUnitTest {
         assertEquals(expected, expected.toFile().resolve("anything").parentPath)
     }
 
-    // TODO: Implement toPath() (Native)
-//    @Test
-//    fun givenFile_whenHasTrailingSlashes_thenIgnoresThem() {
-//        val path = buildString {
-//            append(' ')
-//            repeat(3) { append(SYSTEM_PATH_SEPARATOR) }
-//        }
-//
-//        assertNull(File(path).parent)
-//    }
+    @Test
+    fun givenFile_whenHasTrailingSlashes_thenIgnoresThem() {
+        val path = buildString {
+            append(' ')
+            repeat(3) { append(SysPathSep) }
+        }
+
+        assertNull(path.toFile().parentPath)
+    }
 }

library/file/src/commonTest/kotlin/io/matthewnelson/kmp/file/ResolveUnitTest.kt

@@ -15,7 +15,18 @@
  **/
 package io.matthewnelson.kmp.file
 
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
 class ResolveUnitTest {
 
-    // TODO
+    @Test
+    fun givenFile_whenResolve_thenIsExpected() {
+        assertEquals("", "".toFile().resolve("").path)
+        assertEquals("c", "".toFile().resolve("c").path)
+        assertEquals("p${SysPathSep}c", "p".toFile().resolve("c").path)
+        assertEquals("p${SysPathSep}..", "p".toFile().resolve("..").path)
+        assertEquals("p${SysPathSep}p2${SysPathSep}..", "p".toFile().resolve("p2").resolve("..").path)
+        assertEquals("${SysPathSep}c", "p".toFile().resolve("${SysPathSep}c").path)
+    }
 }

library/file/src/commonTest/kotlin/io/matthewnelson/kmp/file/WriteUnitTest.kt

@@ -20,6 +20,7 @@ import io.matthewnelson.encoding.core.Encoder.Companion.encodeToString
 import kotlin.random.Random
 import kotlin.test.Test
 import kotlin.test.assertEquals
+import kotlin.test.fail
 
 class WriteUnitTest {
 
@@ -67,4 +68,16 @@ class WriteUnitTest {
             tmp.delete()
         }
     }
+
+    @Test
+    fun givenFile_whenDirDoesNotExist_thenThrowsIOException() {
+        val tmp = randomTemp().resolve(randomName()).resolve(randomName())
+
+        try {
+            tmp.writeUtf8("Hello World!")
+            fail()
+        } catch (_: IOException) {
+            // pass
+        }
+    }
 }

library/file/src/darwinMain/kotlin/io/matthewnelson/kmp/file/FileDarwin.kt

@@ -20,7 +20,7 @@ import kotlinx.cinterop.toKString
 import platform.posix.getenv
 
 @OptIn(ExperimentalForeignApi::class)
-public actual val SYSTEM_TEMP_DIRECTORY: File by lazy {
+public actual val SysTempDir: File by lazy {
     val tmpdir = getenv("TMPDIR")
     (tmpdir?.toKString() ?: "/tmp").toFile()
 }

library/file/src/jsMain/kotlin/io/matthewnelson/kmp/file/FileJs.kt

@@ -21,15 +21,15 @@ import io.matthewnelson.kmp.file.internal.*
 import io.matthewnelson.kmp.file.internal.errorCode
 import io.matthewnelson.kmp.file.internal.path_sep
 
-public actual val SYSTEM_PATH_SEPARATOR: Char by lazy {
+public actual val SysPathSep: Char by lazy {
     try {
         path_sep.first()
     } catch (_: Throwable) {
         '/'
     }
 }
 
-public actual val SYSTEM_TEMP_DIRECTORY: File by lazy {
+public actual val SysTempDir: File by lazy {
     try {
         os_tmpdir()
     } catch (_: Throwable) {

library/file/src/jsMain/kotlin/io/matthewnelson/kmp/file/internal/JsPlatform.kt

@@ -18,8 +18,17 @@
 package io.matthewnelson.kmp.file.internal
 
 import io.matthewnelson.kmp.file.DelicateFileApi
+import io.matthewnelson.kmp.file.SysPathSep
 import io.matthewnelson.kmp.file.toIOException
 
+internal actual val IsWindows: Boolean by lazy {
+    try {
+        os_platform() == "win32"
+    } catch (_: Throwable) {
+        SysPathSep == '\\'
+    }
+}
+
 internal actual fun fs_chmod(path: String, mode: String) {
     try {
         fs_chmodSync(path, mode)

library/file/src/jsTest/kotlin/io/matthewnelson/kmp/file/JsTestPlatform.kt

@@ -15,16 +15,7 @@
  **/
 package io.matthewnelson.kmp.file
 
-import io.matthewnelson.kmp.file.internal.os_platform
-
 actual val isJvm: Boolean = false
 actual val isNative: Boolean = false
 actual val isNodejs: Boolean = true
 actual val isSimulator: Boolean = false
-actual val isWindows: Boolean by lazy {
-    try {
-        os_platform() == "win32"
-    } catch (_: Throwable) {
-        SYSTEM_PATH_SEPARATOR == '\\'
-    }
-}

library/file/src/jvmMain/kotlin/io/matthewnelson/kmp/file/FileJvm.kt

@@ -25,16 +25,16 @@ import kotlin.io.resolve as _resolve
 import kotlin.io.writeBytes as _writeBytes
 import kotlin.io.writeText as _writeText
 
-public actual typealias File = java.io.File
-
 @JvmField
-public actual val SYSTEM_PATH_SEPARATOR: Char = File.separatorChar
+public actual val SysPathSep: Char = File.separatorChar
 
 @JvmField
-public actual val SYSTEM_TEMP_DIRECTORY: File = System
+public actual val SysTempDir: File = System
     .getProperty("java.io.tmpdir")
     .toFile()
 
+public actual typealias File = java.io.File
+
 public actual fun File.normalize(): File = _normalize()
 
 @Throws(IOException::class)

library/file/src/linuxMain/kotlin/io/matthewnelson/kmp/file/FileLinux.kt

@@ -20,7 +20,7 @@ import kotlinx.cinterop.toKString
 import platform.posix.getenv
 
 @OptIn(ExperimentalForeignApi::class)
-public actual val SYSTEM_TEMP_DIRECTORY: File by lazy {
+public actual val SysTempDir: File by lazy {
     val tmpdir = getenv("TMPDIR")
     (tmpdir?.toKString() ?: "/tmp").toFile()
 }