Add unit tests and extract testable pure helpers

Move pure logic (DLNA time conversion, SOAP XML extraction, DIDL-Lite
metadata construction, MIME mapping, SSDP header parsing) out of
DlnaMediaController, LocalFileServer and SsdpDeviceDiscovery into
internal util objects, and cover them with a 69-test JUnit 5 suite.
No behavior change; the CI test step now actually executes tests.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: yinnho

CHANGELOG.md

@@ -5,6 +5,14 @@ All notable changes to the UPnPCast library will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### ✨ Added
+- **Unit tests**: the project's first test suite (69 tests) covers DLNA time parsing/formatting, SOAP XML value extraction (position/volume/mute), DIDL-Lite metadata construction (MIME/class detection, XML escaping, subtitle resources, verbatim override), MIME type mapping and SSDP header parsing — making the CI `test` step meaningful
+
+### 🔧 Changed
+- Pure logic extracted from `DlnaMediaController`, `LocalFileServer` and `SsdpDeviceDiscovery` into internal helpers (`UpnpTime`, `SoapXml`, `MetadataBuilder`, `MimeTypes`, `SsdpHeaders`) with no behavior change
+
 ## [1.2.0] - 2026-09-02
 
 ### ✨ Added

app/src/main/java/com/yinnho/upnpcast/internal/discovery/SsdpDeviceDiscovery.kt

@@ -13,6 +13,7 @@ import java.util.concurrent.Executor
 import java.util.concurrent.ExecutorService
 import java.util.concurrent.Executors
 import java.util.concurrent.atomic.AtomicBoolean
+import com.yinnho.upnpcast.internal.util.SsdpHeaders
 
 /**
  * SSDP device discovery service
@@ -224,9 +225,9 @@ internal class SsdpDeviceDiscovery(
      */
     private fun processNotify(message: String, fromAddress: InetAddress) {
         try {
-            val nts = extractHeader(message, "NTS")
+            val nts = SsdpHeaders.extract(message, "NTS")
             if (nts == "ssdp:alive") {
-                val headers = parseSsdpHeaders(message)
+                val headers = SsdpHeaders.parse(message)
                 val location = headers["location"]
 
                 if (location != null) {
@@ -241,9 +242,9 @@ internal class SsdpDeviceDiscovery(
                     processSsdpResponse(message, fromAddress)
                 }
             } else if (nts == "ssdp:byebye") {
-                val usn = extractHeader(message, "USN")
+                val usn = SsdpHeaders.extract(message, "USN")
                 if (usn != null) {
-                    val headers = parseSsdpHeaders(message)
+                    val headers = SsdpHeaders.parse(message)
                     val location = headers["location"]
                     if (location != null) {
                         synchronized(processedLock) {
@@ -258,36 +259,12 @@ internal class SsdpDeviceDiscovery(
         }
     }
 
-    /**
-     * Extract HTTP header information
-     */
-    private fun extractHeader(message: String, headerName: String): String? {
-        val regex = "$headerName:\\s*(.+)".toRegex(RegexOption.IGNORE_CASE)
-        return regex.find(message)?.groupValues?.get(1)?.trim()
-    }
-
-    /**
-     * Parse SSDP header information
-     */
-    private fun parseSsdpHeaders(message: String): Map<String, String> {
-        val headers = mutableMapOf<String, String>()
-        message.lines().forEach { line ->
-            val colonIndex = line.indexOf(':')
-            if (colonIndex > 0) {
-                val key = line.substring(0, colonIndex).trim().lowercase()
-                val value = line.substring(colonIndex + 1).trim()
-                headers[key] = value
-            }
-        }
-        return headers
-    }
-
     /**
      * Process SSDP response
      */
     private fun processSsdpResponse(response: String, fromAddress: InetAddress) {
         try {
-            val headers = parseSsdpHeaders(response)
+            val headers = SsdpHeaders.parse(response)
             val location = headers["location"]
             val usn = headers["usn"]
 

app/src/main/java/com/yinnho/upnpcast/internal/localcast/LocalFileServer.kt

@@ -8,6 +8,7 @@ import java.io.File
 import java.io.FileInputStream
 import java.lang.ref.WeakReference
 import kotlin.random.Random
+import com.yinnho.upnpcast.internal.util.MimeTypes
 
 /**
  * Local file server based on NanoHTTPD
@@ -226,7 +227,7 @@ internal class LocalFileServer private constructor(
 
         val response = newFixedLengthResponse(
             if (rangeHeader != null) Response.Status.PARTIAL_CONTENT else Response.Status.OK,
-            getMimeType(file.name),
+            MimeTypes.fromFileName(file.name),
             inputStream,
             contentLength
         )
@@ -247,28 +248,4 @@ internal class LocalFileServer private constructor(
         Log.d(TAG, "Serving file: ${file.name}, range: $rangeStart-$rangeEnd/$fileSize")
         return response
     }
-
-    /**
-     * Resolve MIME type from the file extension; some TVs reject or
-     * mis-handle unknown content types.
-     */
-    private fun getMimeType(fileName: String): String {
-        val extension = fileName.substringAfterLast('.', "").lowercase()
-        return when (extension) {
-            "mp4", "m4v" -> "video/mp4"
-            "mkv", "webm" -> "video/x-matroska"
-            "avi" -> "video/x-msvideo"
-            "mov" -> "video/quicktime"
-            "ts", "m2ts" -> "video/mp2t"
-            "flv" -> "video/x-flv"
-            "3gp" -> "video/3gpp"
-            "mp3" -> "audio/mpeg"
-            "flac" -> "audio/flac"
-            "aac", "m4a" -> "audio/mp4"
-            "wav" -> "audio/x-wav"
-            "ogg", "oga" -> "audio/ogg"
-            "srt" -> "text/srt"
-            else -> "application/octet-stream"
-        }
-    }
 }

app/src/main/java/com/yinnho/upnpcast/internal/media/DlnaMediaController.kt

@@ -11,6 +11,9 @@ import java.util.Locale
 import com.yinnho.upnpcast.CastOptions
 import com.yinnho.upnpcast.internal.discovery.RemoteDevice
 import com.yinnho.upnpcast.internal.discovery.DeviceDescriptionParser
+import com.yinnho.upnpcast.internal.util.MetadataBuilder
+import com.yinnho.upnpcast.internal.util.SoapXml
+import com.yinnho.upnpcast.internal.util.UpnpTime
 
 /**
  * DLNA media controller with SOAP-based control implementation
@@ -93,7 +96,7 @@ internal class DlnaMediaController(private val device: RemoteDevice) {
         if (!checkAvailable()) return@withContext false
 
         try {
-            val setUriSuccess = setMediaUri(mediaUrl, createMetadata(title, episodeLabel, mediaUrl, options))
+            val setUriSuccess = setMediaUri(mediaUrl, MetadataBuilder.build(title, episodeLabel, mediaUrl, options))
             if (!setUriSuccess) return@withContext false
 
             val playSuccess = control("play")
@@ -216,7 +219,7 @@ internal class DlnaMediaController(private val device: RemoteDevice) {
                     is String -> value.toLongOrNull() ?: return false
                     else -> return false
                 }
-                val timeString = formatTime(positionMs)
+                val timeString = UpnpTime.format(positionMs)
                 executeAVTransportAction("Seek", "\n                        <Unit>REL_TIME</Unit>\n                        <Target>${escapeXmlContent(timeString)}</Target>")
             }
 
@@ -263,7 +266,7 @@ internal class DlnaMediaController(private val device: RemoteDevice) {
             </u:GetPositionInfo>
         """.trimIndent(),
         needResponse = true,
-        parser = ::parsePositionInfo
+        parser = SoapXml::parsePositionInfo
     )
 
     /**
@@ -281,54 +284,9 @@ internal class DlnaMediaController(private val device: RemoteDevice) {
             </u:GetTransportInfo>
         """.trimIndent(),
         needResponse = true,
-        parser = { response -> parseXmlValue(response, "CurrentTransportState") { it.trim() } }
+        parser = { response -> SoapXml.extractValue(response, "CurrentTransportState")?.trim() }
     )
 
-    /**
-     * Parse playback position information
-     */
-    private fun parsePositionInfo(response: String): Pair<Long, Long>? {
-        try {
-            // Simple XML parsing to get RelTime and TrackDuration
-            val relTimePattern = "<RelTime>(.*?)</RelTime>".toRegex()
-            val durationPattern = "<TrackDuration>(.*?)</TrackDuration>".toRegex()
-            
-            val relTimeMatch = relTimePattern.find(response)
-            val durationMatch = durationPattern.find(response)
-            
-            val currentTime = relTimeMatch?.groupValues?.get(1)?.let { parseTimeToMs(it) } ?: 0L
-            val totalTime = durationMatch?.groupValues?.get(1)?.let { parseTimeToMs(it) } ?: 0L
-            
-            return Pair(currentTime, totalTime)
-        } catch (e: Exception) {
-            Log.e(tag, "Failed to parse position info: ${e.message}")
-            return null
-        }
-    }
-    
-    /**
-     * Parse time string to milliseconds
-     */
-    private fun parseTimeToMs(timeString: String): Long {
-        try {
-            if (timeString == "NOT_IMPLEMENTED" || timeString.isEmpty()) {
-                return 0L
-            }
-            
-            val parts = timeString.split(":")
-            if (parts.size == 3) {
-                val hours = parts[0].toLongOrNull() ?: 0L
-                val minutes = parts[1].toLongOrNull() ?: 0L
-                val seconds = parts[2].toDoubleOrNull() ?: 0.0
-                
-                return (hours * 3600 + minutes * 60 + seconds).toLong() * 1000
-            }
-            return 0L
-        } catch (e: Exception) {
-            return 0L
-        }
-    }
-    
     /**
      * Generic SOAP request - handles both Boolean and String responses
      */
@@ -387,42 +345,6 @@ internal class DlnaMediaController(private val device: RemoteDevice) {
         }
     }
 
-    /**
-     * Generic XML value parser
-     */
-    private fun <T> parseXmlValue(
-        response: String, 
-        tagName: String, 
-        converter: (String) -> T?
-    ): T? {
-        try {
-            val pattern = "<$tagName>(.*?)</$tagName>".toRegex()
-            val match = pattern.find(response)
-            return match?.groupValues?.get(1)?.let { converter(it) }
-        } catch (e: Exception) {
-            Log.e(tag, "Failed to parse $tagName from response: ${e.message}")
-            return null
-        }
-    }
-    
-    /**
-     * Parse volume from response
-     */
-    private fun parseVolumeFromResponse(response: String): Int? = 
-        parseXmlValue(response, "CurrentVolume") { it.toIntOrNull() }
-    
-    /**
-     * Parse mute state from response
-     */
-    private fun parseMuteFromResponse(response: String): Boolean? = 
-        parseXmlValue(response, "CurrentMute") { value ->
-            when (value) {
-                "1", "true", "True" -> true
-                "0", "false", "False" -> false
-                else -> null
-            }
-        }
-    
     /**
      * Basic XML escape (common characters)
      */
@@ -446,70 +368,7 @@ internal class DlnaMediaController(private val device: RemoteDevice) {
      * XML escape for URLs (basic only)
      */
     private fun escapeXmlUrl(url: String): String = escapeXmlBasic(url)
-    
-    /**
-     * Create DIDL-Lite metadata
-     *
-     * [CastOptions.metadata] is sent verbatim when provided. Otherwise the
-     * metadata is generated, honoring the mimeType/upnpClass overrides and
-     * attaching the subtitle resource when [CastOptions.subtitleUri] is set
-     * (the Samsung `sec:SubtitleUri` extension is included as well).
-     */
-    private fun createMetadata(
-        title: String,
-        episodeLabel: String,
-        mediaUrl: String = "",
-        options: CastOptions = CastOptions()
-    ): String {
-        options.metadata?.let { return it }
-
-        val displayTitle = if (episodeLabel.isNotEmpty()) "$title - $episodeLabel" else title
-        val safeDisplayTitle = escapeXmlContent(displayTitle)
-        val safeMediaUrl = escapeXmlUrl(mediaUrl)
-
-        val mediaType = options.mimeType ?: when {
-            mediaUrl.contains(".mp4", ignoreCase = true) -> "video/mp4"
-            mediaUrl.contains(".mkv", ignoreCase = true) -> "video/x-matroska"
-            mediaUrl.contains(".m3u8", ignoreCase = true) -> "application/vnd.apple.mpegurl"
-            mediaUrl.contains(".mp3", ignoreCase = true) -> "audio/mpeg"
-            else -> "video/mp4"
-        }
-
-        val upnpClass = options.upnpClass ?: if (mediaType.startsWith("video") || mediaType.contains("mpegurl")) {
-            "object.item.videoItem"
-        } else {
-            "object.item.audioItem.musicTrack"
-        }
-
-        val safeSubtitleUri = options.subtitleUri?.let { escapeXmlUrl(it) }
-        val subtitleRes = safeSubtitleUri
-            ?.let { "\n        <res protocolInfo=\"http-get:*:${options.subtitleMimeType}:*\">$it</res>" }
-            ?: ""
-        val subtitleElement = safeSubtitleUri
-            ?.let { "\n        <sec:SubtitleUri>$it</sec:SubtitleUri>" }
-            ?: ""
-        val secNamespace = if (safeSubtitleUri != null) " xmlns:sec=\"http://www.samsung.com/sec/\"" else ""
 
-        return """<DIDL-Lite xmlns="urn:schemas-upnp-org:metadata-1-0/DIDL-Lite/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:upnp="urn:schemas-upnp-org:metadata-1-0/upnp/"$secNamespace>
-    <item id="1" parentID="0" restricted="1">
-        <dc:title>$safeDisplayTitle</dc:title>
-        <upnp:class>$upnpClass</upnp:class>$subtitleElement
-        <res protocolInfo="http-get:*:$mediaType:*">$safeMediaUrl</res>$subtitleRes
-    </item>
-</DIDL-Lite>"""
-    }
-    
-    /**
-     * Time format
-     */
-    private fun formatTime(positionMs: Long): String {
-        val totalSeconds = positionMs / 1000
-        val hours = totalSeconds / 3600
-        val minutes = (totalSeconds % 3600) / 60
-        val seconds = totalSeconds % 60
-        return String.format(Locale.ROOT, "%02d:%02d:%02d", hours, minutes, seconds)
-    }
-    
     /**
      * Execute RenderingControl action - unified method for both set and get operations
      */
@@ -538,12 +397,12 @@ internal class DlnaMediaController(private val device: RemoteDevice) {
     /**
      * Get current volume
      */
-    suspend fun getVolumeAsync(): Int? = executeRenderingControl("GetVolume", needResponse = true, parser = ::parseVolumeFromResponse)
+    suspend fun getVolumeAsync(): Int? = executeRenderingControl("GetVolume", needResponse = true, parser = SoapXml::parseVolume)
 
     /**
      * Get current mute state
      */
-    suspend fun getMuteAsync(): Boolean? = executeRenderingControl("GetMute", needResponse = true, parser = ::parseMuteFromResponse)
+    suspend fun getMuteAsync(): Boolean? = executeRenderingControl("GetMute", needResponse = true, parser = SoapXml::parseMute)