Fixes test file loader for iOS

quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip01Core/hints/HintIndexerTest.kt

@@ -56,18 +56,20 @@ class HintIndexerTest {
                 )
             }
 
-        val relays =
-            TestResourceLoader()
-                .loadString("relayDB.txt")
-                .split('\n')
-                .mapNotNull {
-                    val relay = RelayUrlNormalizer.normalizeOrNull(it)
-                    if (relay == null || relay.isLocalHost()) {
-                        null
-                    } else {
-                        relay
+        val relays by
+            lazy {
+                TestResourceLoader()
+                    .loadString("relayDB.txt")
+                    .split('\n')
+                    .mapNotNull {
+                        val relay = RelayUrlNormalizer.normalizeOrNull(it)
+                        if (relay == null || relay.isLocalHost()) {
+                            null
+                        } else {
+                            relay
+                        }
                     }
-                }
+            }
 
         val indexer by lazy {
             val result = HintIndexer()

quartz/src/iosTest/kotlin/com/vitorpamplona/quartz/TestResourceLoader.kt

@@ -32,11 +32,22 @@ import platform.darwin.NSObjectMeta
 actual class TestResourceLoader {
     @OptIn(ExperimentalForeignApi::class, BetaInteropApi::class)
     actual fun loadString(file: String): String {
-        val bundle = NSBundle.Companion.bundleForClass(BundleMarker)
+        // Split the filename and extension (e.g., "data.json" -> "data", "json")
+        val basename = file.substringBeforeLast(".")
+        val extension = file.substringAfterLast(".", "")
+
+        // Locate the file in the main application bundle
         val path =
-            bundle.pathForResource(file, ofType = null)
+            NSBundle.mainBundle.pathForResource(basename, ofType = extension)
                 ?: throw IllegalArgumentException("Resource not found: $file")
-        return NSString.Companion.stringWithContentsOfFile(path, encoding = NSUTF8StringEncoding, error = null)!!
+
+        // Read the file content as a UTF-8 string
+        return NSString
+            .stringWithContentsOfFile(
+                path = path,
+                encoding = NSUTF8StringEncoding,
+                error = null,
+            ).toString()
     }
 
     private class BundleMarker : NSObject() {