.editorconfig

@@ -10,4 +10,7 @@ max_line_length = 120
 tab_width = 4
 
 [{*.yaml,*.yml}]
-indent_size = 2
+indent_size = 2
+
+[{*.kt,*.kts}]
+ij_kotlin_packages_to_use_import_on_demand = org.junit.jupiter.api

src/main/kotlin/filesystem/FSCreator.kt

@@ -8,7 +8,10 @@ import java.nio.file.Path
 class FSCreator {
     // Create entry, leaving existing folders' contents, but overwriting existing files.
     @Throws(FileSystemException::class)
-    fun create(entryToCreate: FSEntry, destination: String) {
+    fun create(
+        entryToCreate: FSEntry,
+        destination: String,
+    ) {
         val queue = ArrayDeque<Pair<FSEntry, Path>>()
         queue.add(entryToCreate to Path.of(destination))
 
@@ -20,7 +23,8 @@ class FSCreator {
                     is FSFile -> Files.createFile(path)
                     is FSFolder -> Files.createDirectory(path)
                 }
-            } catch (_: FileAlreadyExistsException) {} // Allow files/folders to already exist.
+            } catch (_: FileAlreadyExistsException) {
+            } // Allow files/folders to already exist.
             when (entry) {
                 is FSFile -> Files.write(path, entry.content.toByteArray())
                 is FSFolder -> queue.addAll(entry.entries.map { it to path })

src/main/kotlin/filesystem/FSEntry.kt

@@ -4,6 +4,6 @@ package filesystem
 // (as we expect), and it also makes the class abstract as required.
 sealed class FSEntry(val name: String)
 
-class FSFile(name: String, val content: String): FSEntry(name)
+class FSFile(name: String, val content: String) : FSEntry(name)
 
-class FSFolder(name: String, val entries: List<FSEntry>): FSEntry(name)
+class FSFolder(name: String, val entries: List<FSEntry>) : FSEntry(name)

src/test/kotlin/filesystem/FSCreatorTest.kt

@@ -29,19 +29,36 @@ class FSCreatorTest {
     fun `create entries`() {
         val readme = FSFile("README", "Hello World!")
         val gomod = FSFile("go.mod", "module example.com/hello-world\n\ngo1.21.5")
-        val maingo = FSFile("main.go", "package main\n\nimport \"example.com/hello-world/utils\"\n\n" +
-            "func main() {\n\tprintln(\"Hello World!\")\n}")
-        val helloworldgo = FSFile("hello-world.go", "package utils\n\nfunc PrintHelloWorld() {\n" +
-            "\tprintln(\"Hello World!\")\n}")
+        val maingo =
+            FSFile(
+                "main.go",
+                "package main\n\nimport \"example.com/hello-world/utils\"\n\n" +
+                    "func main() {\n\tprintln(\"Hello World!\")\n}",
+            )
+        val helloworldgo =
+            FSFile(
+                "hello-world.go",
+                "package utils\n\nfunc PrintHelloWorld() {\n" +
+                    "\tprintln(\"Hello World!\")\n}",
+            )
         assertDoesNotThrow("should create entries") {
-            creator.create(FSFolder("folder", listOf(
-                readme,
-                gomod,
-                maingo,
-                FSFolder("utils", listOf(
-                    helloworldgo
-                ))
-            )), "_tmp")
+            creator.create(
+                FSFolder(
+                    "folder",
+                    listOf(
+                        readme,
+                        gomod,
+                        maingo,
+                        FSFolder(
+                            "utils",
+                            listOf(
+                                helloworldgo,
+                            ),
+                        ),
+                    ),
+                ),
+                "_tmp",
+            )
         }
         // If objects don't exist, these functions will throw anyway, so don't explicitly check for existence.
         // Similarly, don't explicitly check if an object is a directory.
@@ -54,25 +71,46 @@ class FSCreatorTest {
     @Test
     fun `create existing entries`() {
         assertDoesNotThrow("creation one") {
-            creator.create(FSFolder("folder", listOf(
-                FSFolder("sub-folder", listOf(
-                    FSFile("hi", "hi")
-                )),
-                FSFolder("another-folder", listOf()),
-                FSFile("1.txt", "One!"),
-                FSFile("2.txt", "Two!")
-            )), "_tmp")
+            creator.create(
+                FSFolder(
+                    "folder",
+                    listOf(
+                        FSFolder(
+                            "sub-folder",
+                            listOf(
+                                FSFile("hi", "hi"),
+                            ),
+                        ),
+                        FSFolder("another-folder", listOf()),
+                        FSFile("1.txt", "One!"),
+                        FSFile("2.txt", "Two!"),
+                    ),
+                ),
+                "_tmp",
+            )
         }
         assertDoesNotThrow("creation two") {
-            creator.create(FSFolder("folder", listOf(
-                FSFolder("another-folder", listOf(
-                    FSFolder("secrets", listOf(
-                        FSFile("secret", "P4ssW0rd")
-                    ))
-                )),
-                FSFile("1.txt", "One is a good number"),
-                FSFile("3.txt", "Three!")
-            )), "_tmp")
+            creator.create(
+                FSFolder(
+                    "folder",
+                    listOf(
+                        FSFolder(
+                            "another-folder",
+                            listOf(
+                                FSFolder(
+                                    "secrets",
+                                    listOf(
+                                        FSFile("secret", "P4ssW0rd"),
+                                    ),
+                                ),
+                            ),
+                        ),
+                        FSFile("1.txt", "One is a good number"),
+                        FSFile("3.txt", "Three!"),
+                    ),
+                ),
+                "_tmp",
+            )
         }
         assertEquals("hi", Files.readString(Path.of("_tmp/folder/sub-folder/hi")))
         assertEquals("P4ssW0rd", Files.readString(Path.of("_tmp/folder/another-folder/secrets/secret")))