Verify FSEntry name

src/main/kotlin/filesystem/FSCreator.kt

@@ -1,7 +1,7 @@
 package filesystem
 
 import java.nio.file.FileAlreadyExistsException
-import kotlin.io.path.Path
+import java.nio.file.Path
 import kotlin.io.path.createDirectory
 import kotlin.io.path.createFile
 import kotlin.io.path.writeText
@@ -10,27 +10,21 @@ class FSCreator {
     /**
      * Create entry, leaving existing folders' contents, but overwriting existing files.
      * @throws CyclicFolderException Cyclic folders cannot be created.
-     * @throws DuplicateEntryNameException A folder or sub-folder contains entries with duplicate names.
      */
-    @Throws(CyclicFolderException::class, DuplicateEntryNameException::class)
+    @Throws(CyclicFolderException::class)
     fun create(
         entryToCreate: FSEntry,
         destination: String,
     ) {
         // No point in running anything if we know the input is invalid.
-        if (entryToCreate is FSFolder) {
+        if (entryToCreate is FSFolder && entryToCreate.isCyclic()) {
-            if (entryToCreate.isCyclic()) {
+            throw CyclicFolderException()
-                throw CyclicFolderException()
-            }
-            if (entryToCreate.deepHasDuplicateNames()) {
-                throw DuplicateEntryNameException()
-            }
         }
 
         val queue =
             ArrayDeque(
                 listOf(
-                    entryToCreate to Path(destination),
+                    entryToCreate to Path.of(destination),
                 ),
             )
 
@@ -52,6 +46,4 @@ class FSCreator {
     }
 }
 
-class CyclicFolderException : Exception("Cyclic FSFolders are not supported")
+class CyclicFolderException : Exception("Cyclic FSFolders are not supported")
-
-class DuplicateEntryNameException : Exception("Folder contains entries with duplicate names")

src/main/kotlin/filesystem/FSEntry.kt

@@ -34,26 +34,6 @@ class FSFolder(name: String, val entries: List<FSEntry>) : FSEntry(name) {
         }
         return false
     }
-
-    /**
-     * Check whether a folder contains multiple entries with the same name.
-     */
-    fun hasDuplicateNames(): Boolean {
-        val seen = HashSet<String>()
-        return entries.any { !seen.add(it.name) }
-    }
-
-    internal fun deepHasDuplicateNames(): Boolean {
-        val queue = ArrayDeque(listOf(this))
-        while (queue.isNotEmpty()) {
-            val entry = queue.removeFirst()
-            if (entry.hasDuplicateNames()) {
-                return true
-            }
-            queue.addAll(entry.entries.mapNotNull { it as? FSFolder })
-        }
-        return false
-    }
 }
 
 class InvalidEntryNameException(name: String) : Exception("Invalid FSEntry name: '$name'")

src/test/kotlin/filesystem/FSCreatorTest.kt

@@ -104,7 +104,6 @@ class FSCreatorTest {
                     "folder",
                     listOf(
                         FSFolder(
-                            // Repeated name should be fine here (not throw)
                             "folder",
                             listOf(
                                 FSFolder(
@@ -153,34 +152,4 @@ class FSCreatorTest {
             creator.create(folder4, "_tmp")
         }
     }
-
-    @Test
-    fun `create throws on folder with duplicate names`() {
-        val folder =
-            FSFolder(
-                "folder",
-                listOf(
-                    FSFile("README.md", "# Test File"),
-                    FSFile("hello-world.txt", "Hello World!"),
-                    FSFolder(
-                        "src",
-                        listOf(
-                            FSFile("README.md", "# Source files"),
-                            FSFolder(
-                                "solution",
-                                listOf(
-                                    FSFile("solution.py", "print('1 + 1 = 1')"),
-                                    FSFile("tmp", "A temporary file"),
-                                    FSFolder("tmp", listOf()),
-                                ),
-                            ),
-                        ),
-                    ),
-                    FSFolder("tmp", listOf()),
-                ),
-            )
-        assertThrows<DuplicateEntryNameException> {
-            creator.create(folder, "_tmp")
-        }
-    }
 }

src/test/kotlin/filesystem/FSEntryTest.kt

@@ -1,34 +1,10 @@
 package filesystem
 
-import org.junit.jupiter.api.*
+import org.junit.jupiter.api.Test
 import kotlin.test.assertFalse
 import kotlin.test.assertTrue
 
 class FSEntryTest {
-    @Test
-    fun `valid name entries`() {
-        assertDoesNotThrow("should construct FSFile and FSFolder without throwing") {
-            FSFile("A file with a name.tar.xz", "Contents")
-            FSFolder(".a folder with a name", listOf())
-        }
-    }
-
-    @Test
-    fun `invalid name entries`() {
-        assertThrows<InvalidEntryNameException> {
-            FSFile("File/here", "Contents")
-        }
-        assertThrows<InvalidEntryNameException> {
-            FSFolder("Folder/here", listOf())
-        }
-        assertThrows<InvalidEntryNameException> {
-            FSFolder(".", listOf())
-        }
-        assertThrows<InvalidEntryNameException> {
-            FSFolder("/", listOf())
-        }
-    }
-
     @Test
     fun `non-cyclic folder`() {
         val folder =
@@ -63,74 +39,4 @@ class FSEntryTest {
         assertTrue(folder3.isCyclic())
         assertTrue(folder4.isCyclic())
     }
-
-    @Test
-    fun `no duplicate names folder`() {
-        val folder =
-            FSFolder(
-                "folder",
-                listOf(
-                    FSFile("README.md", "# Test File"),
-                    FSFile("hello-world.txt", "Hello World!"),
-                    FSFolder(
-                        "src",
-                        listOf(
-                            FSFile("README.md", "# Source files"),
-                            FSFile("solution-1.py", "print('1 + 1 = 1')"),
-                            FSFile("solution-2.py", "print('1 + 1 = 1')"),
-                        ),
-                    ),
-                    FSFolder("tmp", listOf()),
-                ),
-            )
-        assertFalse(folder.hasDuplicateNames())
-        assertFalse(folder.deepHasDuplicateNames())
-    }
-
-    @Test
-    fun `shallow duplicate names folder`() {
-        val folder =
-            FSFolder(
-                "folder",
-                listOf(
-                    FSFile("README.md", "# Test File"),
-                    FSFile("hello-world.txt", "Hello World!"),
-                    FSFolder(
-                        "src",
-                        listOf(
-                            FSFile("README.md", "# Source files"),
-                            FSFile("solution-1.py", "print('1 + 1 = 1')"),
-                            FSFile("solution-2.py", "print('1 + 1 = 1')"),
-                        ),
-                    ),
-                    FSFolder("tmp", listOf()),
-                    FSFile("tmp", "A temporary file"),
-                ),
-            )
-        assertTrue(folder.hasDuplicateNames())
-        assertTrue(folder.deepHasDuplicateNames())
-    }
-
-    @Test
-    fun `deep duplicate names folder`() {
-        val folder =
-            FSFolder(
-                "folder",
-                listOf(
-                    FSFile("README.md", "# Test File"),
-                    FSFile("hello-world.txt", "Hello World!"),
-                    FSFolder(
-                        "src",
-                        listOf(
-                            FSFile("README.md", "# Source files"),
-                            FSFile("solution-1.py", "print('1 + 1 = 1')"),
-                            FSFile("solution-1.py", "print('1 + 1 = 1')"),
-                        ),
-                    ),
-                    FSFolder("tmp", listOf()),
-                ),
-            )
-        assertFalse(folder.hasDuplicateNames())
-        assertTrue(folder.deepHasDuplicateNames())
-    }
 }