perf(metadata): preserve typed values across the Rust extension bridge

android/app/src/androidTest/kotlin/com/zarz/spotiflac/ExtensionMetadataBridgeTest.kt

@@ -0,0 +1,63 @@
+package com.zarz.spotiflac
+
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.platform.app.InstrumentationRegistry
+import com.spotiflac.backend.CancellationDomain
+import com.spotiflac.backend.CancellationRegistry
+import com.spotiflac.backend.ExtensionManager
+import java.io.File
+import org.json.JSONObject
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class ExtensionMetadataBridgeTest {
+    @Test
+    fun applicationMetadataRoutePreservesProviderStampingAndCancellation() {
+        val context = InstrumentationRegistry.getInstrumentation().targetContext
+        val root = File(context.cacheDir, "extension-bridge-${System.nanoTime()}").apply { mkdirs() }
+        val id = "example.metadata"
+        try {
+            val sources = File(root, "sources").apply { mkdirs() }
+            val extension = File(sources, id).apply { mkdirs() }
+            File(extension, "manifest.json").writeText(
+                """{"name":"$id","displayName":"Example Metadata","version":"1","description":"Generic bridge fixture","type":["metadata_provider"]}""",
+            )
+            File(extension, "index.js").writeText("""
+                function collection(id) {
+                    if (id === "missing") return null;
+                    return {id, name:"Album 音楽 🎵", artists:"Artist Café", total_tracks:128,
+                        tracks:Array.from({length:128}, (_, i) => ({id:"track-"+i,
+                            name:"歌 🎵 "+i, artists:"Artist Café", album_name:"Album 音楽 🎵",
+                            provider_id:"supplied", duration_ms:123456, track_number:i+1}))};
+                }
+                registerExtension({getAlbum:collection,getPlaylist:collection});
+            """.trimIndent())
+            ExtensionManager(sources.path, File(root, "data").path, "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=", "1", 10000uL).use { manager ->
+                manager.loadAll()
+                manager.setEnabled(id, true)
+                for ((kind, method) in listOf("album" to "getAlbum", "playlist" to "getPlaylist")) {
+                    val legacy = JSONObject(manager.providerCall(id, method, "[\"fixture\"]", null, 10000uL))
+                    val result = JSONObject(manager.getProviderMetadataJson(id, kind, "fixture", null))
+                    val tracks = result.getJSONArray("track_list")
+                    assertEquals(128, tracks.length())
+                    assertEquals(id, tracks.getJSONObject(127).getString("provider_id"))
+                    assertEquals(legacy.getJSONArray("tracks").getJSONObject(127).getString("name"), tracks.getJSONObject(127).getString("name"))
+                    assertEquals("Album 音楽 🎵", result.getJSONObject("${kind}_info").getString("name"))
+                    assertTrue(runCatching { manager.getProviderMetadataJson(id, kind, "missing", null) }.isFailure)
+                }
+                CancellationRegistry(CancellationDomain.EXTENSION_REQUEST).use { registry ->
+                    registry.acquire("bridge-cancel").use { lease ->
+                        registry.cancel("bridge-cancel")
+                        assertTrue(runCatching { manager.getProviderMetadataJson(id, "album", "fixture", lease) }.isFailure)
+                    }
+                }
+                assertEquals(128, JSONObject(manager.getProviderMetadataJson(id, "album", "fixture", null)).getJSONArray("track_list").length())
+            }
+        } finally {
+            root.deleteRecursively()
+        }
+    }
+}