Fix _metadata population (#114)

* fix metadata logic

* optimize building of sets

* more optimizations

Author: prayansh

core/src/main/java/com/segment/analytics/kotlin/core/platform/plugins/DestinationMetadataPlugin.kt

@@ -31,15 +31,31 @@ class DestinationMetadataPlugin : Plugin {
             ?.filter { it.enabled && it !is SegmentDestination }
         val metadata = DestinationMetadata().apply {
             // Mark all loaded destinations as bundled
-            this.bundled = enabledDestinations?.map { it.key }
+            val bundled = buildSet { enabledDestinations?.forEach { add(it.key) } }
 
+            // All active integrations, not in `bundled` are put in `unbundled`
             // All unbundledIntegrations not in `bundled` are put in `unbundled`
-            this.unbundled = analyticsSettings.integrations["Segment.io"]?.safeJsonObject
-                ?.get("unbundledIntegrations")?.safeJsonArray?.map { (it as JsonPrimitive).content }
-                ?.filter { !(bundled?.contains(it) ?: false) }
+            val unbundled = buildSet {
+                analyticsSettings.integrations.keys.forEach {
+                    if (it != "Segment.io" && !bundled.contains(it)) {
+                        add(it)
+                    }
+                }
+
+                analyticsSettings.integrations["Segment.io"]?.safeJsonObject
+                    ?.get("unbundledIntegrations")?.safeJsonArray
+                    ?.forEach {
+                        val content = (it as JsonPrimitive).content
+                        if (!bundled.contains(content)) {
+                            add(content)
+                        }
+                    }
+            }
 
             // `bundledIds` for mobile is empty
             this.bundledIds = emptyList()
+            this.bundled = bundled.toList()
+            this.unbundled = unbundled.toList()
         }
 
         val payload = event.copy<BaseEvent>().apply {

core/src/test/kotlin/com/segment/analytics/kotlin/core/platform/plugins/DestinationMetadataPluginTests.kt

@@ -109,4 +109,51 @@ class DestinationMetadataPluginTests {
         assertEquals(expected, actual)
         assertEquals(emptyJsonObject, actual.integrations)
     }
+
+    @Test
+    fun `plugin respects both integrations list and unbundled list`() {
+        val trackEvent = TrackEvent(
+            event = "clicked",
+            properties = buildJsonObject { put("behaviour", "good") })
+            .apply {
+                messageId = "qwerty-1234"
+                anonymousId = "anonId"
+                integrations = emptyJsonObject
+                context = emptyJsonObject
+                timestamp = epochTimestamp
+                _metadata = DestinationMetadata()
+            }
+        val mixpanelDest = object : DestinationPlugin() {
+            override val key: String = "Mixpanel"
+        }
+        analytics.add(mixpanelDest)
+        analytics.manuallyEnableDestination(mixpanelDest)
+        plugin.update(Settings(
+            integrations = buildJsonObject {
+                put("Segment.io", buildJsonObject {
+                    put("apiKey", "123")
+                    put("apiHost", "api.segment.io/v1")
+                    put("unbundledIntegrations", buildJsonArray {
+                        add("Customer.io")
+                        add("Mixpanel")
+                        add("Amplitude")
+                        add("dest1")
+                    })
+                })
+                put("dest1", true)
+                put("dest2", true)
+            }
+        ), Plugin.UpdateType.Initial)
+
+        val expected = trackEvent.copy<TrackEvent>().apply {
+            _metadata = DestinationMetadata(
+                unbundled = listOf("dest1", "dest2", "Customer.io","Amplitude"),
+                bundled = listOf("Mixpanel"),
+                bundledIds = emptyList()
+            )
+        }
+        val actual = plugin.execute(trackEvent)
+        assertEquals(expected, actual)
+        assertEquals(emptyJsonObject, actual.integrations)
+    }
 }