Android: Add CD image unit tests

Add synthetic ISO9660, CUE, CCD, and MDS fixtures for JVM unit tests. Cover CD image sector mapping, audio extraction, install cleanup, playlist generation, and output path validation.
2026-09-22 22:48:08 +03:00 · 2026-07-05 16:21:17 +09:00
parent 172c76b4e2
commit 1d897c72d0
4 changed files with 798 additions and 22 deletions
@@ -85,6 +85,7 @@ dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.4'
+    testImplementation 'junit:junit:4.13.2'
 }

 static String gitRevision() {
@@ -140,6 +140,35 @@ internal class CdImageReader private constructor(
            }
        }

+        internal fun openForFile(
+            imageFile: File,
+            metadataName: String? = null,
+            metadataBytes: ByteArray? = null,
+        ): CdImageReader {
+            val image = RandomAccessImage.open(imageFile)
+            try {
+                if (metadataName == null) {
+                    return CdImageReader(image, listOf(null, TrackInfo.iso(image.size)))
+                }
+                val tracks = when {
+                    metadataName.lowercase(Locale.US).endsWith(".cue") -> {
+                        parseCue(metadataBytes?.toString(Charsets.UTF_8) ?: "", image.size)
+                    }
+                    metadataName.lowercase(Locale.US).endsWith(".ccd") -> {
+                        parseCcd(metadataBytes?.toString(Charsets.UTF_8) ?: "", image.size)
+                    }
+                    metadataName.lowercase(Locale.US).endsWith(".mds") -> {
+                        parseMds(metadataBytes ?: ByteArray(0))
+                    }
+                    else -> throw InstallFailureException(R.string.unsupported_cd_image)
+                }
+                return CdImageReader(image, tracks)
+            } catch (e: Exception) {
+                image.close()
+                throw e
+            }
+        }
+
        private fun selectImageFiles(files: List<SelectedInstallFile>): SelectedImageFiles {
            if (files.isEmpty()) {
                throw InstallFailureException(R.string.unsupported_cd_image)
@@ -488,6 +517,10 @@ private class RandomAccessImage private constructor(
    }

    companion object {
+        internal fun open(file: File): RandomAccessImage {
+            return RandomAccessImage(FileInputStream(file).channel, null, null)
+        }
+
        fun open(
            contentResolver: ContentResolver,
            file: SelectedInstallFile,
@@ -70,6 +70,23 @@ class GameInstaller(private val store: GameStore) {
        }
    }

+    internal suspend fun installCdImageForTest(
+        cdImage: CdImageReader,
+        progressCallback: suspend (String) -> Unit
+    ): File {
+        val dir = store.createDirForGame()
+        var committed = false
+        try {
+            val gameDir = extractCdImage(cdImage, dir, progressCallback)
+            committed = true
+            return gameDir
+        } finally {
+            if (!committed && !dir.deleteRecursively()) {
+                Log.w("launcher", "Failed to delete incomplete install directory: $dir")
+            }
+        }
+    }
+
    private suspend fun extractFiles(
        input: InputStream,
        outDir: File,
@@ -107,30 +124,38 @@ class GameInstaller(private val store: GameStore) {
    ): File {
        progressCallback("metadata parsing")
        CdImageReader.open(contentResolver, files, tempDir).use { cdImage ->
-            val fs = Iso9660FileSystem(cdImage)
-            val gameData = fs.findGameDataDirectory()
-                ?: throw InstallFailureException(R.string.cannot_find_game_data_directory)
-            var foundAld = false
-            fs.extractDirectory(gameData, "GAMEDATA") { path, input ->
-                val resolvedPath = resolveOutputPath(outDir, path)
-                resolvedPath.file.parentFile?.mkdirs()
-                progressCallback(resolvedPath.relativePath)
-                FileOutputStream(resolvedPath.file).buffered().use {
-                    input.copyTo(it)
-                }
-                if (File(path).name.matches(""".*?s[a-z]\.ald""".toRegex(RegexOption.IGNORE_CASE))) {
-                    foundAld = true
-                }
-            }
-            if (!foundAld) {
-                throw InstallFailureException(R.string.cannot_find_ald)
-            }
-            File(outDir, Launcher.GAMEDIR_FILE).writeText("GAMEDATA")
-            extractAudioTracks(cdImage, File(outDir, "GAMEDATA"), progressCallback)
-            return File(outDir, "GAMEDATA")
+            return extractCdImage(cdImage, outDir, progressCallback)
        }
    }

+    private suspend fun extractCdImage(
+        cdImage: CdImageReader,
+        outDir: File,
+        progressCallback: suspend (String) -> Unit
+    ): File {
+        val fs = Iso9660FileSystem(cdImage)
+        val gameData = fs.findGameDataDirectory()
+            ?: throw InstallFailureException(R.string.cannot_find_game_data_directory)
+        var foundAld = false
+        fs.extractDirectory(gameData, "GAMEDATA") { path, input ->
+            val resolvedPath = resolveOutputPath(outDir, path)
+            resolvedPath.file.parentFile?.mkdirs()
+            progressCallback(resolvedPath.relativePath)
+            FileOutputStream(resolvedPath.file).buffered().use {
+                input.copyTo(it)
+            }
+            if (File(path).name.matches(""".*?s[a-z]\.ald""".toRegex(RegexOption.IGNORE_CASE))) {
+                foundAld = true
+            }
+        }
+        if (!foundAld) {
+            throw InstallFailureException(R.string.cannot_find_ald)
+        }
+        File(outDir, Launcher.GAMEDIR_FILE).writeText("GAMEDATA")
+        extractAudioTracks(cdImage, File(outDir, "GAMEDATA"), progressCallback)
+        return File(outDir, "GAMEDATA")
+    }
+
    private suspend fun extractAudioTracks(
        cdImage: CdImageReader,
        gameDir: File,
@@ -152,7 +177,7 @@ class GameInstaller(private val store: GameStore) {
            }
            playlist[track - 1] = relativePath
        }
-        File(gameDir, Launcher.PLAYLIST_FILE).writeText(playlist.joinToString("\n").trimEnd('\n'))
+        File(gameDir, Launcher.PLAYLIST_FILE).writeText(playlist.joinToString("\n") { it ?: "" }.trimEnd('\n'))
    }
 }

@@ -206,6 +231,9 @@ private class GameConfigWriter {
 internal data class ResolvedOutputPath(val file: File, val relativePath: String)

 internal fun resolveOutputPath(baseDir: File, relativePath: String): ResolvedOutputPath {
+    if (File(relativePath).isAbsolute) {
+        throw IOException("Output path is absolute: $relativePath")
+    }
    val canonicalBase = baseDir.canonicalFile
    val file = File(canonicalBase, relativePath).canonicalFile
    if (!isFileInsideDirectory(file, canonicalBase)) {
@@ -0,0 +1,714 @@
+/* Copyright (C) 2026 <KichikuouChrome@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+*/
+package io.github.kichikuou.xsystem35
+
+import kotlinx.coroutines.runBlocking
+import org.junit.Assert.assertArrayEquals
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Assert.fail
+import org.junit.Rule
+import org.junit.Test
+import org.junit.rules.TemporaryFolder
+import java.io.ByteArrayOutputStream
+import java.io.File
+import java.nio.charset.Charset
+
+class Iso9660FileSystemTest {
+    @get:Rule
+    val tmp = TemporaryFolder()
+
+    @Test
+    fun extractsGameDataDirectoryFromPrimaryDescriptor() = runBlocking {
+        val iso = SyntheticIsoBuilder()
+            .addGameDataFile("SA.ALD;1", "ald".toByteArray())
+            .addGameDataFile("SUB/FILE.TXT;1", "text".toByteArray())
+            .writeTo(tmp.newFile("game.iso"))
+
+        CdImageReader.openForFile(iso).use { reader ->
+            val fs = Iso9660FileSystem(reader)
+            val gameData = fs.findGameDataDirectory()
+                ?: throw AssertionError("GAMEDATA directory was not found")
+            val extracted = mutableMapOf<String, ByteArray>()
+
+            fs.extractDirectory(gameData, "GAMEDATA") { path, input ->
+                extracted[path] = input.readBytes()
+            }
+
+            assertArrayEquals("ald".toByteArray(), extracted["GAMEDATA/SA.ALD"])
+            assertArrayEquals("text".toByteArray(), extracted["GAMEDATA/SUB/FILE.TXT"])
+        }
+    }
+
+    @Test
+    fun decodesPrimaryDescriptorNamesAsShiftJis() = runBlocking {
+        val name = "表.TXT;1"
+        val iso = SyntheticIsoBuilder()
+            .addGameDataFile(name, "sjis".toByteArray())
+            .writeTo(tmp.newFile("sjis.iso"))
+
+        CdImageReader.openForFile(iso).use { reader ->
+            val fs = Iso9660FileSystem(reader)
+            val gameData = fs.findGameDataDirectory()
+                ?: throw AssertionError("GAMEDATA directory was not found")
+            val extracted = mutableMapOf<String, ByteArray>()
+
+            fs.extractDirectory(gameData, "GAMEDATA") { path, input ->
+                extracted[path] = input.readBytes()
+            }
+
+            assertArrayEquals("sjis".toByteArray(), extracted["GAMEDATA/表.TXT"])
+        }
+    }
+
+    @Test
+    fun prefersJolietDescriptorOverPrimaryDescriptor() = runBlocking {
+        val iso = SyntheticIsoBuilder()
+            .addGameDataFile("PRIMARY.TXT;1", "primary".toByteArray())
+            .addJolietGameDataFile("日本語.TXT;1", "joliet".toByteArray())
+            .writeTo(tmp.newFile("joliet.iso"))
+
+        CdImageReader.openForFile(iso).use { reader ->
+            val fs = Iso9660FileSystem(reader)
+            val gameData = fs.findGameDataDirectory()
+                ?: throw AssertionError("GAMEDATA directory was not found")
+            val extracted = mutableMapOf<String, ByteArray>()
+
+            fs.extractDirectory(gameData, "GAMEDATA") { path, input ->
+                extracted[path] = input.readBytes()
+            }
+
+            assertFalse(extracted.containsKey("GAMEDATA/PRIMARY.TXT"))
+            assertArrayEquals("joliet".toByteArray(), extracted["GAMEDATA/日本語.TXT"])
+        }
+    }
+
+    @Test
+    fun rejectsInvalidVolumeDescriptorSignature() {
+        val iso = tmp.newFile("invalid.iso")
+        iso.writeBytes(ByteArray(18 * CdImageReader.ISO_SECTOR_SIZE))
+
+        val e = assertInstallFailure(R.string.invalid_iso9660_image) {
+            CdImageReader.openForFile(iso).use { Iso9660FileSystem(it) }
+        }
+        assertEquals(R.string.invalid_iso9660_image, e.msgId)
+    }
+}
+
+class CdImageReaderTest {
+    @get:Rule
+    val tmp = TemporaryFolder()
+
+    @Test
+    fun readsIsoSectorAt2048ByteOffset() {
+        val sector0 = sectorFilledWith(0x10)
+        val sector1 = sectorFilledWith(0x20)
+        val image = tmp.newFile("plain.iso")
+        image.writeBytes(sector0 + sector1)
+
+        CdImageReader.openForFile(image).use { reader ->
+            val buffer = ByteArray(CdImageReader.ISO_SECTOR_SIZE)
+
+            reader.readSector(1, buffer)
+
+            assertArrayEquals(sector1, buffer)
+            assertTrue(reader.audioTracks().isEmpty())
+        }
+    }
+
+    @Test
+    fun cueMode12048ReadsDataSector() {
+        val payload = sectorFilledWith(0x31)
+        val image = tmp.newFile("mode2048.bin")
+        image.writeBytes(payload)
+
+        CdImageReader.openForFile(image, "mode2048.cue", cue("MODE1/2048").toByteArray()).use { reader ->
+            val buffer = ByteArray(CdImageReader.ISO_SECTOR_SIZE)
+
+            reader.readSector(0, buffer)
+
+            assertArrayEquals(payload, buffer)
+        }
+    }
+
+    @Test
+    fun cueMode12352ReadsPayloadAtOffset16() {
+        val payload = sectorFilledWith(0x42)
+        val image = tmp.newFile("mode2352.bin")
+        image.writeBytes(rawDataSector(payload, 0x11))
+
+        CdImageReader.openForFile(image, "mode2352.cue", cue("MODE1/2352").toByteArray()).use { reader ->
+            val buffer = ByteArray(CdImageReader.ISO_SECTOR_SIZE)
+
+            reader.readSector(0, buffer)
+
+            assertArrayEquals(payload, buffer)
+        }
+    }
+
+    @Test
+    fun cuePregapAdvancesDataTrackStart() {
+        val pregapPayload = sectorFilledWith(0x21)
+        val dataPayload = sectorFilledWith(0x22)
+        val image = tmp.newFile("pregap.bin")
+        image.writeBytes(rawDataSector(pregapPayload, 0x01) + rawDataSector(dataPayload, 0x02))
+        val metadata = """
+            FILE "pregap.bin" BINARY
+              TRACK 01 MODE1/2352
+                INDEX 00 00:00:00
+                INDEX 01 00:00:01
+        """.trimIndent()
+
+        CdImageReader.openForFile(image, "pregap.cue", metadata.toByteArray()).use { reader ->
+            val buffer = ByteArray(CdImageReader.ISO_SECTOR_SIZE)
+
+            reader.readSector(1, buffer)
+
+            assertArrayEquals(dataPayload, buffer)
+        }
+    }
+
+    @Test
+    fun extractsCueAudioTrackAsWav() {
+        val dataPayload = sectorFilledWith(0x33)
+        val audio = ByteArray(RAW_AUDIO_SECTOR_SIZE) { it.toByte() }
+        val image = tmp.newFile("audio.bin")
+        image.writeBytes(rawDataSector(dataPayload, 0) + audio)
+        val metadata = """
+            FILE "audio.bin" BINARY
+              TRACK 01 MODE1/2352
+                INDEX 01 00:00:00
+              TRACK 02 AUDIO
+                INDEX 01 00:00:01
+        """.trimIndent()
+
+        CdImageReader.openForFile(image, "audio.cue", metadata.toByteArray()).use { reader ->
+            val output = ByteArrayOutputStream()
+
+            assertEquals(listOf(2), reader.audioTracks())
+            reader.extractAudioTrack(2, output)
+
+            val wav = output.toByteArray()
+            assertEquals("RIFF", wav.decodeAscii(0, 4))
+            assertEquals(RAW_AUDIO_SECTOR_SIZE + 36, wav.readLeInt(4))
+            assertEquals("WAVE", wav.decodeAscii(8, 4))
+            assertEquals("data", wav.decodeAscii(36, 4))
+            assertEquals(RAW_AUDIO_SECTOR_SIZE, wav.readLeInt(40))
+            assertEquals(44100, wav.readLeInt(24))
+            assertEquals(2, wav.readLeShort(22))
+            assertEquals(16, wav.readLeShort(34))
+            assertArrayEquals(audio, wav.copyOfRange(44, 44 + RAW_AUDIO_SECTOR_SIZE))
+        }
+    }
+
+    @Test
+    fun rejectsUnsupportedCueMode() {
+        val image = tmp.newFile("unsupported.bin")
+        image.writeBytes(ByteArray(CdImageReader.ISO_SECTOR_SIZE))
+
+        assertInstallFailure(R.string.unsupported_cd_image) {
+            CdImageReader.openForFile(image, "unsupported.cue", cue("MODE2/2352").toByteArray())
+        }
+    }
+
+    @Test
+    fun ccdUsesMode0ForAudioAndMode1PayloadOffsetForData() {
+        val dataPayload = sectorFilledWith(0x52)
+        val audio = ByteArray(RAW_AUDIO_SECTOR_SIZE) { (255 - it).toByte() }
+        val image = tmp.newFile("disc.img")
+        image.writeBytes(rawDataSector(dataPayload, 0x08) + audio)
+        val metadata = """
+            [TRACK 1]
+            MODE=1
+            INDEX 1=0
+            [TRACK 2]
+            MODE=0
+            INDEX 1=1
+        """.trimIndent()
+
+        CdImageReader.openForFile(image, "disc.ccd", metadata.toByteArray()).use { reader ->
+            val buffer = ByteArray(CdImageReader.ISO_SECTOR_SIZE)
+            val output = ByteArrayOutputStream()
+
+            reader.readSector(0, buffer)
+            reader.extractAudioTrack(2, output)
+
+            assertArrayEquals(dataPayload, buffer)
+            assertEquals(listOf(2), reader.audioTracks())
+            assertArrayEquals(audio, output.toByteArray().copyOfRange(44, 44 + RAW_AUDIO_SECTOR_SIZE))
+        }
+    }
+
+    @Test
+    fun mdsMapsModeAAToDataAndModeA9ToAudio() {
+        val dataPayload = sectorFilledWith(0x61)
+        val audio = ByteArray(RAW_AUDIO_SECTOR_SIZE) { (it * 3).toByte() }
+        val image = tmp.newFile("disc.mdf")
+        image.writeBytes(rawDataSector(dataPayload, 0x09) + audio)
+
+        CdImageReader.openForFile(image, "disc.mds", mds(track1Sectors = 1, track2Sectors = 1)).use { reader ->
+            val buffer = ByteArray(CdImageReader.ISO_SECTOR_SIZE)
+            val output = ByteArrayOutputStream()
+
+            reader.readSector(0, buffer)
+            reader.extractAudioTrack(2, output)
+
+            assertArrayEquals(dataPayload, buffer)
+            assertEquals(listOf(2), reader.audioTracks())
+            assertArrayEquals(audio, output.toByteArray().copyOfRange(44, 44 + RAW_AUDIO_SECTOR_SIZE))
+        }
+    }
+
+    @Test
+    fun rejectsMdsWithoutMediaDescriptorSignature() {
+        val image = tmp.newFile("bad.mdf")
+        image.writeBytes(ByteArray(RAW_AUDIO_SECTOR_SIZE))
+
+        assertInstallFailure(R.string.unsupported_cd_image) {
+            CdImageReader.openForFile(image, "bad.mds", ByteArray(0x70))
+        }
+    }
+}
+
+class GameInstallerCdImageTest {
+    @get:Rule
+    val tmp = TemporaryFolder()
+
+    @Test
+    fun installsDataOnlyIso() = runBlocking {
+        val root = tmp.newFolder("root")
+        val iso = SyntheticIsoBuilder()
+            .addGameDataFile("SA.ALD;1", "ald".toByteArray())
+            .addGameDataFile("TITLE.TXT;1", "title".toByteArray())
+            .writeTo(tmp.newFile("game.iso"))
+
+        CdImageReader.openForFile(iso).use { reader ->
+            val gameDir = GameInstaller(GameStore(root)).installCdImageForTest(reader) {}
+
+            assertEquals(File(root, "0/GAMEDATA").canonicalFile, gameDir.canonicalFile)
+            assertEquals("GAMEDATA", File(root, "0/${Launcher.GAMEDIR_FILE}").readText())
+            assertEquals("ald", File(gameDir, "SA.ALD").readText())
+            assertEquals("title", File(gameDir, "TITLE.TXT").readText())
+        }
+    }
+
+    @Test
+    fun installsCueAudioTrackAndPlaylist() = runBlocking {
+        val root = tmp.newFolder("root")
+        val isoSector = SyntheticIsoBuilder()
+            .addGameDataFile("SA.ALD;1", "ald".toByteArray())
+            .toByteArray()
+        val dataSectors = isoSector.toList().chunked(CdImageReader.ISO_SECTOR_SIZE)
+            .joinToByteArray { rawDataSector(it.toByteArray(), 0) }
+        val audio = ByteArray(RAW_AUDIO_SECTOR_SIZE) { (it and 0x7f).toByte() }
+        val image = tmp.newFile("audio.bin")
+        image.writeBytes(dataSectors + audio)
+        val dataSectorCount = isoSector.size / CdImageReader.ISO_SECTOR_SIZE
+        val metadata = """
+            FILE "audio.bin" BINARY
+              TRACK 01 MODE1/2352
+                INDEX 01 00:00:00
+              TRACK 02 AUDIO
+                INDEX 01 ${dataSectorCount.toMsf()}
+        """.trimIndent()
+
+        CdImageReader.openForFile(image, "audio.cue", metadata.toByteArray()).use { reader ->
+            val gameDir = GameInstaller(GameStore(root)).installCdImageForTest(reader) {}
+
+            val wav = File(gameDir, "cdda/track02.wav")
+            assertTrue(wav.exists())
+            assertEquals("\ncdda/track02.wav", File(gameDir, Launcher.PLAYLIST_FILE).readText())
+        }
+    }
+
+    @Test
+    fun rejectsIsoWithoutGameDataDirectoryAndDeletesIncompleteInstall() = runBlocking {
+        val root = tmp.newFolder("root")
+        val iso = SyntheticIsoBuilder(includeGameData = false).writeTo(tmp.newFile("nogamedata.iso"))
+
+        CdImageReader.openForFile(iso).use { reader ->
+            assertInstallFailure(R.string.cannot_find_game_data_directory) {
+                runBlocking {
+                    GameInstaller(GameStore(root)).installCdImageForTest(reader) {}
+                }
+            }
+        }
+
+        assertFalse(File(root, "0").exists())
+    }
+
+    @Test
+    fun rejectsIsoWithoutAldAndDeletesIncompleteInstall() = runBlocking {
+        val root = tmp.newFolder("root")
+        val iso = SyntheticIsoBuilder()
+            .addGameDataFile("README.TXT;1", "readme".toByteArray())
+            .writeTo(tmp.newFile("noald.iso"))
+
+        CdImageReader.openForFile(iso).use { reader ->
+            assertInstallFailure(R.string.cannot_find_ald) {
+                runBlocking {
+                    GameInstaller(GameStore(root)).installCdImageForTest(reader) {}
+                }
+            }
+        }
+
+        assertFalse(File(root, "0").exists())
+    }
+
+    @Test
+    fun resolveOutputPathRejectsTraversal() {
+        val base = tmp.newFolder("out")
+
+        assertThrowsIOException {
+            resolveOutputPath(base, "../evil")
+        }
+        assertThrowsIOException {
+            resolveOutputPath(base, File(base.parentFile, "evil").absolutePath)
+        }
+    }
+}
+
+private class SyntheticIsoBuilder(
+    private val includeGameData: Boolean = true,
+) {
+    private val primaryFiles = mutableMapOf<String, ByteArray>()
+    private val jolietFiles = mutableMapOf<String, ByteArray>()
+
+    fun addGameDataFile(path: String, content: ByteArray): SyntheticIsoBuilder {
+        primaryFiles[path] = content
+        return this
+    }
+
+    fun addJolietGameDataFile(path: String, content: ByteArray): SyntheticIsoBuilder {
+        jolietFiles[path] = content
+        return this
+    }
+
+    fun writeTo(file: File): File {
+        file.writeBytes(toByteArray())
+        return file
+    }
+
+    fun toByteArray(): ByteArray {
+        val sectors = MutableList(80) { ByteArray(CdImageReader.ISO_SECTOR_SIZE) }
+        var nextSector = 30
+        val primaryTree = buildTree(primaryFiles, Charset.forName("Shift_JIS"))
+        val primaryRoot = writeTree(sectors, primaryTree, ROOT_SECTOR, GAMEDATA_SECTOR, nextSector, false)
+        nextSector = primaryRoot.nextSector
+
+        writeVolumeDescriptor(sectors[16], 1, ROOT_SECTOR, CdImageReader.ISO_SECTOR_SIZE, false)
+        var terminatorSector = 17
+        if (jolietFiles.isNotEmpty()) {
+            val jolietTree = buildTree(jolietFiles, Charsets.UTF_16BE)
+            writeTree(sectors, jolietTree, JOLIET_ROOT_SECTOR, JOLIET_GAMEDATA_SECTOR, nextSector, true)
+            writeVolumeDescriptor(sectors[17], 2, JOLIET_ROOT_SECTOR, CdImageReader.ISO_SECTOR_SIZE, true)
+            terminatorSector = 18
+        }
+        writeTerminator(sectors[terminatorSector])
+        return sectors.flattenToByteArray()
+    }
+
+    private fun buildTree(files: Map<String, ByteArray>, charset: Charset): DirectoryNode {
+        val root = DirectoryNode("")
+        if (!includeGameData) {
+            return root
+        }
+        val gameData = DirectoryNode("GAMEDATA")
+        root.directories["GAMEDATA"] = gameData
+        for ((path, content) in files) {
+            var directory = gameData
+            val parts = path.split("/")
+            for (part in parts.dropLast(1)) {
+                directory = directory.directories.getOrPut(part.substringBefore(";")) {
+                    DirectoryNode(part.substringBefore(";"))
+                }
+            }
+            val rawName = parts.last().toByteArray(charset)
+            directory.files.add(FileNode(rawName, content))
+        }
+        return root
+    }
+
+    private fun writeTree(
+        sectors: MutableList<ByteArray>,
+        root: DirectoryNode,
+        rootSector: Int,
+        gameDataSector: Int,
+        firstFileSector: Int,
+        joliet: Boolean,
+    ): TreeWriteResult {
+        var nextSector = firstFileSector
+        root.extent = rootSector
+        root.size = CdImageReader.ISO_SECTOR_SIZE
+        if (includeGameData) {
+            root.directories["GAMEDATA"]!!.extent = gameDataSector
+            root.directories["GAMEDATA"]!!.size = CdImageReader.ISO_SECTOR_SIZE
+        }
+        assignDirectorySectors(root, gameDataSector + 1)
+        nextSector = writeFileContents(sectors, root, nextSector)
+        writeDirectorySector(sectors[rootSector], root, root, joliet)
+        if (includeGameData) {
+            writeDirectorySectors(sectors, root.directories["GAMEDATA"]!!, root, joliet)
+        }
+        return TreeWriteResult(nextSector)
+    }
+
+    private fun assignDirectorySectors(directory: DirectoryNode, nextDirectorySector: Int): Int {
+        var sector = nextDirectorySector
+        for (child in directory.directories.values) {
+            if (child.name == "GAMEDATA") {
+                sector = assignDirectorySectors(child, sector)
+                continue
+            }
+            child.extent = sector++
+            child.size = CdImageReader.ISO_SECTOR_SIZE
+            sector = assignDirectorySectors(child, sector)
+        }
+        return sector
+    }
+
+    private fun writeFileContents(
+        sectors: MutableList<ByteArray>,
+        directory: DirectoryNode,
+        firstFileSector: Int,
+    ): Int {
+        var sector = firstFileSector
+        for (child in directory.directories.values) {
+            sector = writeFileContents(sectors, child, sector)
+        }
+        for (file in directory.files) {
+            file.extent = sector
+            file.size = file.content.size
+            val sectorCount = (file.content.size + CdImageReader.ISO_SECTOR_SIZE - 1) /
+                CdImageReader.ISO_SECTOR_SIZE
+            for (i in 0 until sectorCount) {
+                file.content.copyInto(
+                    sectors[sector + i],
+                    0,
+                    i * CdImageReader.ISO_SECTOR_SIZE,
+                    minOf(file.content.size, (i + 1) * CdImageReader.ISO_SECTOR_SIZE)
+                )
+            }
+            sector += maxOf(1, sectorCount)
+        }
+        return sector
+    }
+
+    private fun writeDirectorySectors(
+        sectors: MutableList<ByteArray>,
+        directory: DirectoryNode,
+        parent: DirectoryNode,
+        joliet: Boolean,
+    ) {
+        writeDirectorySector(sectors[directory.extent], directory, parent, joliet)
+        for (child in directory.directories.values) {
+            writeDirectorySectors(sectors, child, directory, joliet)
+        }
+    }
+
+    private fun writeDirectorySector(
+        sector: ByteArray,
+        directory: DirectoryNode,
+        parent: DirectoryNode,
+        joliet: Boolean,
+    ) {
+        var offset = 0
+        offset += writeRecord(sector, offset, byteArrayOf(0), directory.extent, directory.size, true)
+        offset += writeRecord(sector, offset, byteArrayOf(1), parent.extent, parent.size, true)
+        for (child in directory.directories.values) {
+            val name = if (joliet) child.name.toByteArray(Charsets.UTF_16BE) else child.name.toByteArray()
+            offset += writeRecord(sector, offset, name, child.extent, child.size, true)
+        }
+        for (file in directory.files) {
+            offset += writeRecord(sector, offset, file.rawName, file.extent, file.size, false)
+        }
+    }
+
+    private fun writeVolumeDescriptor(
+        sector: ByteArray,
+        type: Int,
+        rootExtent: Int,
+        rootSize: Int,
+        joliet: Boolean,
+    ) {
+        sector[0] = type.toByte()
+        "CD001".toByteArray(Charsets.US_ASCII).copyInto(sector, 1)
+        sector[6] = 1
+        if (joliet) {
+            sector[88] = 0x25
+            sector[89] = 0x2f
+            sector[90] = 0x45
+        }
+        writeRecord(sector, 156, byteArrayOf(0), rootExtent, rootSize, true)
+    }
+
+    private fun writeTerminator(sector: ByteArray) {
+        sector[0] = 255.toByte()
+        "CD001".toByteArray(Charsets.US_ASCII).copyInto(sector, 1)
+        sector[6] = 1
+    }
+
+    private fun writeRecord(
+        buffer: ByteArray,
+        offset: Int,
+        rawName: ByteArray,
+        extent: Int,
+        size: Int,
+        isDirectory: Boolean,
+    ): Int {
+        val length = 33 + rawName.size + if (rawName.size % 2 == 0) 1 else 0
+        buffer[offset] = length.toByte()
+        buffer.writeLeInt(offset + 2, extent)
+        buffer.writeLeInt(offset + 10, size)
+        buffer[offset + 25] = if (isDirectory) 0x02 else 0x00
+        buffer[offset + 32] = rawName.size.toByte()
+        rawName.copyInto(buffer, offset + 33)
+        return length
+    }
+
+    companion object {
+        private const val ROOT_SECTOR = 20
+        private const val GAMEDATA_SECTOR = 21
+        private const val JOLIET_ROOT_SECTOR = 24
+        private const val JOLIET_GAMEDATA_SECTOR = 25
+    }
+}
+
+private data class DirectoryNode(
+    val name: String,
+    val directories: MutableMap<String, DirectoryNode> = linkedMapOf(),
+    val files: MutableList<FileNode> = mutableListOf(),
+    var extent: Int = 0,
+    var size: Int = 0,
+)
+
+private data class FileNode(
+    val rawName: ByteArray,
+    val content: ByteArray,
+    var extent: Int = 0,
+    var size: Int = 0,
+)
+
+private data class TreeWriteResult(val nextSector: Int)
+
+private const val RAW_AUDIO_SECTOR_SIZE = 2352
+
+private fun cue(mode: String): String = """
+    FILE "image.bin" BINARY
+      TRACK 01 $mode
+        INDEX 01 00:00:00
+""".trimIndent()
+
+private fun mds(track1Sectors: Int, track2Sectors: Int): ByteArray {
+    val bytes = ByteArray(0x70 + 2 * 0x50 + 2 * 8)
+    "MEDIA DESCRIPTOR".toByteArray(Charsets.US_ASCII).copyInto(bytes, 0)
+    bytes[0x62] = 2
+    val track1 = 0x70
+    bytes[track1] = 0xaa.toByte()
+    bytes[track1 + 0x04] = 1
+    bytes.writeLeShort(track1 + 0x10, RAW_AUDIO_SECTOR_SIZE)
+    bytes.writeLeInt(track1 + 0x28, 0)
+    bytes.writeLeInt(0x70 + 2 * 0x50 + 0x04, track1Sectors)
+    val track2 = 0x70 + 0x50
+    bytes[track2] = 0xa9.toByte()
+    bytes[track2 + 0x04] = 2
+    bytes.writeLeShort(track2 + 0x10, RAW_AUDIO_SECTOR_SIZE)
+    bytes.writeLeInt(track2 + 0x28, track1Sectors * RAW_AUDIO_SECTOR_SIZE)
+    bytes.writeLeInt(0x70 + 2 * 0x50 + 8 + 0x04, track2Sectors)
+    return bytes
+}
+
+private fun sectorFilledWith(value: Int): ByteArray {
+    return ByteArray(CdImageReader.ISO_SECTOR_SIZE) { value.toByte() }
+}
+
+private fun rawDataSector(payload: ByteArray, prefixValue: Int): ByteArray {
+    val sector = ByteArray(RAW_AUDIO_SECTOR_SIZE) { prefixValue.toByte() }
+    payload.copyInto(sector, 16, 0, CdImageReader.ISO_SECTOR_SIZE)
+    return sector
+}
+
+private fun Int.toMsf(): String {
+    val minutes = this / (60 * 75)
+    val seconds = this / 75 % 60
+    val frames = this % 75
+    return "%02d:%02d:%02d".format(minutes, seconds, frames)
+}
+
+private fun Iterable<Byte>.toByteArray(): ByteArray {
+    val result = ByteArray(count())
+    forEachIndexed { index, byte -> result[index] = byte }
+    return result
+}
+
+private fun List<ByteArray>.flattenToByteArray(): ByteArray {
+    val result = ByteArray(sumOf { it.size })
+    var offset = 0
+    for (bytes in this) {
+        bytes.copyInto(result, offset)
+        offset += bytes.size
+    }
+    return result
+}
+
+private fun List<List<Byte>>.joinToByteArray(transform: (List<Byte>) -> ByteArray): ByteArray {
+    return map(transform).flattenToByteArray()
+}
+
+private fun ByteArray.decodeAscii(offset: Int, length: Int): String {
+    return String(this, offset, length, Charsets.US_ASCII)
+}
+
+private fun ByteArray.readLeShort(offset: Int): Int {
+    return (this[offset].toInt() and 0xff) or ((this[offset + 1].toInt() and 0xff) shl 8)
+}
+
+private fun ByteArray.readLeInt(offset: Int): Int {
+    return readLeShort(offset) or (readLeShort(offset + 2) shl 16)
+}
+
+private fun ByteArray.writeLeShort(offset: Int, value: Int) {
+    this[offset] = value.toByte()
+    this[offset + 1] = (value shr 8).toByte()
+}
+
+private fun ByteArray.writeLeInt(offset: Int, value: Int) {
+    writeLeShort(offset, value)
+    writeLeShort(offset + 2, value shr 16)
+}
+
+private fun assertInstallFailure(expectedMsgId: Int, block: () -> Unit): InstallFailureException {
+    try {
+        block()
+    } catch (e: InstallFailureException) {
+        assertEquals(expectedMsgId, e.msgId)
+        return e
+    }
+    fail("Expected InstallFailureException")
+    throw AssertionError()
+}
+
+private fun assertThrowsIOException(block: () -> Unit) {
+    try {
+        block()
+    } catch (e: java.io.IOException) {
+        return
+    }
+    fail("Expected IOException")
+}