Begin replacing observables with channels

11 files changed, 280 insertions, 97 deletions

diff --git a/app/build.gradle b/app/build.gradle
index c7d78537..75ffed98 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -100,6 +100,8 @@ android {
             resValue "string", "frost_name", "Frost Debug"
             resValue "string", "frost_web", "Frost Web Debug"
             ext.enableBugsnag = false
+
+            kotlinOptions.freeCompilerArgs += ["-Xuse-experimental=kotlin.Experimental"]
         }
         releaseTest {
             minifyEnabled true
@@ -141,6 +143,7 @@ android {
             includeAndroidResources = true
         }
     }
+
 }
 
 repositories {
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/activities/WebOverlayActivity.kt b/app/src/main/kotlin/com/pitchedapps/frost/activities/WebOverlayActivity.kt
index b706d467..bf04c524 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/activities/WebOverlayActivity.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/activities/WebOverlayActivity.kt
@@ -72,6 +72,7 @@ import com.pitchedapps.frost.views.FrostVideoViewer
 import com.pitchedapps.frost.views.FrostWebView
 import io.reactivex.android.schedulers.AndroidSchedulers
 import io.reactivex.disposables.Disposable
+import kotlinx.coroutines.CoroutineScope
 import okhttp3.HttpUrl
 
 /**
@@ -181,7 +182,6 @@ open class WebOverlayActivityBase(private val forceBasicAgent: Boolean) : BaseAc
             finish()
             return
         }
-
         setFrameContentView(R.layout.activity_web_overlay)
         setSupportActionBar(toolbar)
         supportActionBar?.setDisplayShowHomeEnabled(true)
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/contracts/FrostContentContract.kt b/app/src/main/kotlin/com/pitchedapps/frost/contracts/FrostContentContract.kt
index 50c2fe77..a2c2b05a 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/contracts/FrostContentContract.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/contracts/FrostContentContract.kt
@@ -20,6 +20,10 @@ import android.view.View
 import com.pitchedapps.frost.facebook.FbItem
 import io.reactivex.subjects.BehaviorSubject
 import io.reactivex.subjects.PublishSubject
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.channels.BroadcastChannel
+import kotlinx.coroutines.channels.Channel
 
 /**
  * Created by Allan Wang on 20/12/17.
@@ -29,7 +33,7 @@ import io.reactivex.subjects.PublishSubject
  * Contract for the underlying parent,
  * binds to activities & fragments
  */
-interface FrostContentContainer {
+interface FrostContentContainer : CoroutineScope {
 
     val baseUrl: String
 
@@ -45,8 +49,11 @@ interface FrostContentContainer {
  * Contract for components shared among
  * all content providers
  */
+@UseExperimental(ExperimentalCoroutinesApi::class)
 interface FrostContentParent : DynamicUiContract {
 
+    val scope: CoroutineScope
+
     val core: FrostContentCore
 
     /**
@@ -54,16 +61,22 @@ interface FrostContentParent : DynamicUiContract {
      */
     val refreshObservable: PublishSubject<Boolean>
 
+    val refreshChannel: BroadcastChannel<Boolean>
+
     /**
      * Observable to get data on refresh progress, with range [0, 100]
      */
     val progressObservable: PublishSubject<Int>
 
+    val progressChannel: BroadcastChannel<Int>
+
     /**
      * Observable to get new title data (unique values only)
      */
     val titleObservable: BehaviorSubject<String>
 
+    val titleChannel: BroadcastChannel<String>
+
     var baseUrl: String
 
     var baseEnum: FbItem?
@@ -106,6 +119,9 @@ interface FrostContentParent : DynamicUiContract {
  */
 interface FrostContentCore : DynamicUiContract {
 
+    val scope: CoroutineScope
+        get() = parent.scope
+
     /**
      * Reference to parent
      * Bound through calling [FrostContentParent.bind]
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/fragments/FragmentContract.kt b/app/src/main/kotlin/com/pitchedapps/frost/fragments/FragmentContract.kt
index e24e8308..95322c1c 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/fragments/FragmentContract.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/fragments/FragmentContract.kt
@@ -23,6 +23,8 @@ import com.pitchedapps.frost.contracts.MainActivityContract
 import com.pitchedapps.frost.contracts.MainFabContract
 import com.pitchedapps.frost.views.FrostRecyclerView
 import io.reactivex.disposables.Disposable
+import kotlinx.coroutines.channels.ReceiveChannel
+import kotlinx.coroutines.channels.SendChannel
 
 /**
  * Created by Allan Wang on 2017-11-07.
@@ -102,8 +104,9 @@ interface RecyclerContentContract {
 
     /**
      * Completely handle data reloading
-     * Optional progress emission update
-     * Callback returns [true] for success, [false] otherwise
+     * The progress function allows optional emission of progress values (between 0 and 100).
+     * This can be called from any thread.
+     * Returns [true] for success, [false] otherwise
      */
-    fun reload(progress: (Int) -> Unit, callback: (Boolean) -> Unit)
+    suspend fun reload(progress: (Int) -> Unit): Boolean
 }
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/fragments/RecyclerFragmentBase.kt b/app/src/main/kotlin/com/pitchedapps/frost/fragments/RecyclerFragmentBase.kt
index f77f83ea..98c8f750 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/fragments/RecyclerFragmentBase.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/fragments/RecyclerFragmentBase.kt
@@ -29,16 +29,18 @@ import com.pitchedapps.frost.facebook.parsers.ParseResponse
 import com.pitchedapps.frost.utils.L
 import com.pitchedapps.frost.utils.frostJsoup
 import com.pitchedapps.frost.views.FrostRecyclerView
-import org.jetbrains.anko.doAsync
-import org.jetbrains.anko.uiThread
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
 
 /**
  * Created by Allan Wang on 27/12/17.
  */
-abstract class RecyclerFragment : BaseFragment(), RecyclerContentContract {
+abstract class RecyclerFragment<T, Item : IItem<*, *>> : BaseFragment(), RecyclerContentContract {
 
     override val layoutRes: Int = R.layout.view_content_recycler
 
+    abstract val adapter: ModelAdapter<T, Item>
+
     override fun firstLoadRequest() {
         val core = core ?: return
         if (firstLoad) {
@@ -47,23 +49,30 @@ abstract class RecyclerFragment : BaseFragment(), RecyclerContentContract {
         }
     }
 
-    final override fun reload(progress: (Int) -> Unit, callback: (Boolean) -> Unit) {
-        reloadImpl(progress) {
-            if (it)
-                callback(it)
-            else
-                valid = false
+    final override suspend fun reload(progress: (Int) -> Unit): Boolean {
+        val data = try {
+            reloadImpl(progress)
+        } catch (e: Exception) {
+            null
+        }
+        if (data == null) {
+            valid = false
+            return false
+        }
+        withContext(Dispatchers.Main) {
+            adapter.setNewList(data)
         }
+        return true
     }
 
-    protected abstract fun reloadImpl(progress: (Int) -> Unit, callback: (Boolean) -> Unit)
+    protected abstract suspend fun reloadImpl(progress: (Int) -> Unit): List<T>?
 }
 
-abstract class GenericRecyclerFragment<T, Item : IItem<*, *>> : RecyclerFragment() {
+abstract class GenericRecyclerFragment<T, Item : IItem<*, *>> : RecyclerFragment<T, Item>() {
 
     abstract fun mapper(data: T): Item
 
-    val adapter: ModelAdapter<T, Item> = ModelAdapter { this.mapper(it) }
+    override val adapter: ModelAdapter<T, Item> = ModelAdapter { this.mapper(it) }
 
     final override fun bind(recyclerView: FrostRecyclerView) {
         recyclerView.adapter = getAdapter()
@@ -83,7 +92,7 @@ abstract class GenericRecyclerFragment<T, Item : IItem<*, *>> : RecyclerFragment
     open fun getAdapter(): FastAdapter<IItem<*, *>> = fastAdapter(this.adapter)
 }
 
-abstract class FrostParserFragment<T : Any, Item : IItem<*, *>> : RecyclerFragment() {
+abstract class FrostParserFragment<T : Any, Item : IItem<*, *>> : RecyclerFragment<Item, Item>() {
 
     /**
      * The parser to make this all happen
@@ -94,7 +103,7 @@ abstract class FrostParserFragment<T : Any, Item : IItem<*, *>> : RecyclerFragme
 
     abstract fun toItems(response: ParseResponse<T>): List<Item>
 
-    val adapter: ItemAdapter<Item> = ItemAdapter()
+    override val adapter: ItemAdapter<Item> = ItemAdapter()
 
     final override fun bind(recyclerView: FrostRecyclerView) {
         recyclerView.adapter = getAdapter()
@@ -113,23 +122,20 @@ abstract class FrostParserFragment<T : Any, Item : IItem<*, *>> : RecyclerFragme
      */
     open fun getAdapter(): FastAdapter<IItem<*, *>> = fastAdapter(this.adapter)
 
-    override fun reloadImpl(progress: (Int) -> Unit, callback: (Boolean) -> Unit) {
-        doAsync {
-            progress(10)
-            val cookie = FbCookie.webCookie
-            val doc = getDoc(cookie)
-            progress(60)
-            val response = parser.parse(cookie, doc)
-            if (response == null) {
-                L.i { "RecyclerFragment failed for ${baseEnum.name}" }
-                return@doAsync callback(false)
-            }
-            progress(80)
-            val items = toItems(response)
-            progress(97)
-            uiThread { adapter.setNewList(items) }
-            callback(true)
+    override suspend fun reloadImpl(progress: (Int) -> Unit): List<Item>? = withContext(Dispatchers.IO) {
+        progress(10)
+        val cookie = FbCookie.webCookie
+        val doc = getDoc(cookie)
+        progress(60)
+        val response = parser.parse(cookie, doc)
+        if (response == null) {
+            L.i { "RecyclerFragment failed for ${baseEnum.name}" }
+            return@withContext null
         }
+        progress(80)
+        val items = toItems(response)
+        progress(97)
+        return@withContext items
     }
 }
 
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/fragments/RecyclerFragments.kt b/app/src/main/kotlin/com/pitchedapps/frost/fragments/RecyclerFragments.kt
index ff37b66d..45cf2290 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/fragments/RecyclerFragments.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/fragments/RecyclerFragments.kt
@@ -26,7 +26,7 @@ import com.pitchedapps.frost.facebook.requests.MenuFooterItem
 import com.pitchedapps.frost.facebook.requests.MenuHeader
 import com.pitchedapps.frost.facebook.requests.MenuItem
 import com.pitchedapps.frost.facebook.requests.MenuItemData
-import com.pitchedapps.frost.facebook.requests.fbRequest
+import com.pitchedapps.frost.facebook.requests.fbAuth
 import com.pitchedapps.frost.facebook.requests.getMenuData
 import com.pitchedapps.frost.iitems.ClickableIItemContract
 import com.pitchedapps.frost.iitems.MenuContentIItem
@@ -36,8 +36,9 @@ import com.pitchedapps.frost.iitems.MenuHeaderIItem
 import com.pitchedapps.frost.iitems.NotificationIItem
 import com.pitchedapps.frost.utils.frostJsoup
 import com.pitchedapps.frost.views.FrostRecyclerView
-import org.jetbrains.anko.doAsync
-import org.jetbrains.anko.uiThread
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 
 /**
  * Created by Allan Wang on 27/12/17.
@@ -71,20 +72,16 @@ class MenuFragment : GenericRecyclerFragment<MenuItemData, IItem<*, *>>() {
         ClickableIItemContract.bindEvents(adapter)
     }
 
-    override fun reloadImpl(progress: (Int) -> Unit, callback: (Boolean) -> Unit) {
-        doAsync {
-            val cookie = FbCookie.webCookie
-            progress(10)
-            cookie.fbRequest({ callback(false) }) {
-                progress(30)
-                val data = getMenuData().invoke() ?: return@fbRequest callback(false)
-                if (data.data.isEmpty()) return@fbRequest callback(false)
-                progress(70)
-                val items = data.flatMapValid()
-                progress(90)
-                uiThread { adapter.add(items) }
-                callback(true)
-            }
-        }
+    override suspend fun reloadImpl(progress: (Int) -> Unit): List<MenuItemData>? = withContext(Dispatchers.IO) {
+        val cookie = FbCookie.webCookie ?: return@withContext null
+        progress(10)
+        val auth = fbAuth.fetch(cookie)
+        progress(30)
+        val data = auth.getMenuData().invoke() ?: return@withContext null
+        if (data.data.isEmpty()) return@withContext null
+        progress(70)
+        val items = data.flatMapValid()
+        progress(90)
+        return@withContext items
     }
 }
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/views/FrostContentView.kt b/app/src/main/kotlin/com/pitchedapps/frost/views/FrostContentView.kt
index d17a424c..72b81b37 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/views/FrostContentView.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/views/FrostContentView.kt
@@ -45,6 +45,13 @@ import io.reactivex.disposables.Disposable
 import io.reactivex.rxkotlin.addTo
 import io.reactivex.subjects.BehaviorSubject
 import io.reactivex.subjects.PublishSubject
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.channels.BroadcastChannel
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 
 class FrostContentWeb @JvmOverloads constructor(
     context: Context,
@@ -66,6 +73,7 @@ class FrostContentRecycler @JvmOverloads constructor(
     override val layoutRes: Int = R.layout.view_content_base_recycler
 }
 
+@UseExperimental(ExperimentalCoroutinesApi::class)
 abstract class FrostContentView<out T> @JvmOverloads constructor(
     context: Context,
     attrs: AttributeSet? = null,
@@ -85,7 +93,11 @@ abstract class FrostContentView<out T> @JvmOverloads constructor(
     override val refreshObservable: PublishSubject<Boolean> = PublishSubject.create()
     override val titleObservable: BehaviorSubject<String> = BehaviorSubject.create()
 
-    private val compositeDisposable = CompositeDisposable()
+    override val refreshChannel: BroadcastChannel<Boolean> = BroadcastChannel(Channel.UNLIMITED)
+    override val progressChannel: BroadcastChannel<Int> = BroadcastChannel(Channel.UNLIMITED)
+    override val titleChannel: BroadcastChannel<String> = BroadcastChannel(Channel.UNLIMITED)
+
+    override lateinit var scope: CoroutineScope
 
     override lateinit var baseUrl: String
     override var baseEnum: FbItem? = null
@@ -107,24 +119,6 @@ abstract class FrostContentView<out T> @JvmOverloads constructor(
     protected fun init() {
         inflate(context, layoutRes, this)
         coreView.parent = this
-
-        // bind observables
-        progressObservable.observeOn(AndroidSchedulers.mainThread()).subscribe {
-            progress.invisibleIf(it == 100)
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N)
-                progress.setProgress(it, true)
-            else
-                progress.progress = it
-        }.addTo(compositeDisposable)
-
-        refreshObservable
-            .observeOn(AndroidSchedulers.mainThread())
-            .subscribe {
-                refresh.isRefreshing = it
-                refresh.isEnabled = true
-            }.addTo(compositeDisposable)
-        refresh.setOnRefreshListener { coreView.reload(true) }
-
         reloadThemeSelf()
     }
 
@@ -132,7 +126,34 @@ abstract class FrostContentView<out T> @JvmOverloads constructor(
         baseUrl = container.baseUrl
         baseEnum = container.baseEnum
         init()
+        scope = container
         core.bind(container)
+        refresh.setOnRefreshListener {
+            with(coreView) {
+                reload(true)
+            }
+        }
+        scope.launch(Dispatchers.Default) {
+            launch {
+                for (r in refreshChannel.openSubscription()) {
+                    withContext(Dispatchers.Main) {
+                        refresh.isRefreshing = r
+                        refresh.isEnabled = true
+                    }
+                }
+            }
+            launch {
+                for (p in progressChannel.openSubscription()) {
+                    withContext(Dispatchers.Main) {
+                        progress.invisibleIf(p == 100)
+                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N)
+                            progress.setProgress(p, true)
+                        else
+                            progress.progress = p
+                    }
+                }
+            }
+        }
     }
 
     override fun reloadTheme() {
@@ -155,11 +176,10 @@ abstract class FrostContentView<out T> @JvmOverloads constructor(
     }
 
     override fun destroy() {
-        titleObservable.onComplete()
-        progressObservable.onComplete()
-        refreshObservable.onComplete()
+        titleChannel.close()
+        progressChannel.close()
+        refreshChannel.close()
         core.destroy()
-        compositeDisposable.dispose()
     }
 
     private var dispose: Disposable? = null
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/views/FrostRecyclerView.kt b/app/src/main/kotlin/com/pitchedapps/frost/views/FrostRecyclerView.kt
index 2b9e8f9c..fb20c3ba 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/views/FrostRecyclerView.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/views/FrostRecyclerView.kt
@@ -23,11 +23,14 @@ import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
 import ca.allanwang.kau.utils.circularReveal
 import ca.allanwang.kau.utils.fadeOut
+import com.pitchedapps.frost.R.string.reload
 import com.pitchedapps.frost.contracts.FrostContentContainer
 import com.pitchedapps.frost.contracts.FrostContentCore
 import com.pitchedapps.frost.contracts.FrostContentParent
 import com.pitchedapps.frost.fragments.RecyclerContentContract
 import com.pitchedapps.frost.utils.Prefs
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.launch
 
 /**
  * Created by Allan Wang on 2017-05-29.
@@ -69,11 +72,12 @@ class FrostRecyclerView @JvmOverloads constructor(
 
     override fun reloadBase(animate: Boolean) {
         if (Prefs.animate) fadeOut(onFinish = onReloadClear)
-        parent.refreshObservable.onNext(true)
-        recyclerContract.reload({ parent.progressObservable.onNext(it) }) {
-            parent.progressObservable.onNext(100)
-            parent.refreshObservable.onNext(false)
-            if (Prefs.animate) post { circularReveal() }
+        scope.launch {
+            parent.refreshChannel.send(true)
+            val loaded = recyclerContract.reload { parent.progressChannel.offer(it) }
+            parent.progressChannel.send(100)
+            parent.refreshChannel.send(false)
+            if (Prefs.animate) circularReveal()
         }
     }
 
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/web/FrostChromeClients.kt b/app/src/main/kotlin/com/pitchedapps/frost/web/FrostChromeClients.kt
index 12df8000..1f8118da 100644
--- a/app/src/main/kotlin/com/pitchedapps/frost/web/FrostChromeClients.kt
+++ b/app/src/main/kotlin/com/pitchedapps/frost/web/FrostChromeClients.kt
@@ -43,8 +43,9 @@ import io.reactivex.subjects.Subject
  */
 class FrostChromeClient(web: FrostWebView) : WebChromeClient() {
 
-    private val progress: Subject<Int> = web.parent.progressObservable
-    private val title: BehaviorSubject<String> = web.parent.titleObservable
+    private val progress = web.parent.progressChannel
+    private val title = web.parent.titleChannel
+    private var prevTitle: String? = null
     private val activity = (web.context as? ActivityContract)
     private val context = web.context!!
 
@@ -55,13 +56,14 @@ class FrostChromeClient(web: FrostWebView) : WebChromeClient() {
 
     override fun onReceivedTitle(view: WebView, title: String) {
         super.onReceivedTitle(view, title)
-        if (title.startsWith("http") || this.title.value == title) return
-        this.title.onNext(title)
+        if (title.startsWith("http") || prevTitle == title) return
+        prevTitle = title
+        this.title.offer(title)
     }
 
     override fun onProgressChanged(view: WebView, newProgress: Int) {
         super.onProgressChanged(view, newProgress)
-        progress.onNext(newProgress)
+        progress.offer(newProgress)
     }
 
     override fun onShowFileChooser(
diff --git a/app/src/test/kotlin/com/pitchedapps/frost/MiscTest.kt b/app/src/test/kotlin/com/pitchedapps/frost/MiscTest.kt
index ce125298..2676e37d 100644
--- a/app/src/test/kotlin/com/pitchedapps/frost/MiscTest.kt
+++ b/app/src/test/kotlin/com/pitchedapps/frost/MiscTest.kt
@@ -16,10 +16,16 @@
  */
 package com.pitchedapps.frost
 
-import com.pitchedapps.frost.facebook.requests.call
 import com.pitchedapps.frost.facebook.requests.zip
-import okhttp3.Request
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.asCoroutineDispatcher
+import kotlinx.coroutines.channels.BroadcastChannel
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
 import org.junit.Test
+import java.util.concurrent.Executors
 import kotlin.test.assertTrue
 
 /**
@@ -48,14 +54,30 @@ class MiscTest {
         )
     }
 
-    @Test
-    fun a() {
-        val s = Request.Builder()
-            .url("https://www.allanwang.ca/ecse429/magenta.png")
-            .get()
-            .call().execute().body()!!.string()
-        "�PNG\n\u001A\nIDA�c����?\u0000\u0006�\u0002��p�\u0000\u0000\u0000\u0000IEND�B`�"
-        println("Hello")
-        println(s)
+@Test
+@UseExperimental(ExperimentalCoroutinesApi::class)
+fun channel() {
+    val c = BroadcastChannel<Int>(100)
+    runBlocking {
+        launch(Dispatchers.IO) {
+            println("1 start ${Thread.currentThread()}")
+            for (i in c.openSubscription()) {
+                println("1 $i")
+            }
+            println("1 end ${Thread.currentThread()}")
+        }
+        launch(Dispatchers.IO) {
+            println("2 start ${Thread.currentThread()}")
+            for (i in c.openSubscription()) {
+                println("2 $i")
+            }
+            println("2 end ${Thread.currentThread()}")
+        }
+        c.send(1)
+        c.send(2)
+        c.send(3)
+        delay(1000)
+        c.close()
     }
 }
+}
diff --git a/app/src/test/kotlin/com/pitchedapps/frost/views/FrostContentViewAsyncTest.kt b/app/src/test/kotlin/com/pitchedapps/frost/views/FrostContentViewAsyncTest.kt
new file mode 100644
index 00000000..a179fb98
--- /dev/null
+++ b/app/src/test/kotlin/com/pitchedapps/frost/views/FrostContentViewAsyncTest.kt
@@ -0,0 +1,110 @@
+package com.pitchedapps.frost.views
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExecutorCoroutineDispatcher
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.asCoroutineDispatcher
+import kotlinx.coroutines.async
+import kotlinx.coroutines.channels.BroadcastChannel
+import kotlinx.coroutines.channels.ReceiveChannel
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withContext
+import java.util.concurrent.Executors
+import kotlin.test.AfterTest
+import kotlin.test.BeforeTest
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+/**
+ * Collection of tests around the view thread logic
+ */
+@UseExperimental(ExperimentalCoroutinesApi::class)
+class FrostContentViewAsyncTest {
+
+    /**
+     * Single threaded dispatcher with thread name "main"
+     * Mimics the usage of Android's main dispatcher
+     */
+    private lateinit var mainDispatcher: ExecutorCoroutineDispatcher
+
+    @BeforeTest
+    fun before() {
+        mainDispatcher = Executors.newSingleThreadExecutor { r ->
+            Thread(r, "main")
+        }.asCoroutineDispatcher()
+    }
+
+    @AfterTest
+    fun after() {
+        mainDispatcher.close()
+    }
+
+    /**
+     * Hooks onto the refresh channel for one true -> false cycle.
+     * Returns the list of event ids that were emitted
+     */
+    private suspend fun transition(channel: ReceiveChannel<Pair<Boolean, Int>>): List<Pair<Boolean, Int>> {
+        var refreshed = false
+        return listen(channel) { (refreshing, _) ->
+            if (refreshed && !refreshing)
+                return@listen true
+            if (refreshing)
+                refreshed = true
+            return@listen false
+        }
+    }
+
+    private suspend fun <T> listen(channel: ReceiveChannel<T>, shouldEnd: (T) -> Boolean = { false }): List<T> =
+        withContext(Dispatchers.IO) {
+            val data = mutableListOf<T>()
+            for (c in channel) {
+                data.add(c)
+                if (shouldEnd(c)) break
+            }
+            channel.cancel()
+            return@withContext data
+        }
+
+    /**
+     * When refreshing, we have a temporary subscriber that hooks onto a single cycle.
+     * The refresh channel only contains booleans, but for the sake of identification,
+     * each boolean will have a unique integer attached.
+     *
+     * Things to note:
+     * Subscription should be opened outside of async, since we don't want to miss any events.
+     */
+    @Test
+    fun refreshSubscriptions() {
+        val refreshChannel = BroadcastChannel<Pair<Boolean, Int>>(100)
+        runBlocking {
+            // Listen to all events
+            val fullReceiver = refreshChannel.openSubscription()
+            val fullDeferred = async { listen(fullReceiver) }
+
+            refreshChannel.send(true to 1)
+            refreshChannel.send(false to 2)
+            refreshChannel.send(true to 3)
+
+            val partialReceiver = refreshChannel.openSubscription()
+            val partialDeferred = async { transition(partialReceiver) }
+            refreshChannel.send(false to 4)
+            refreshChannel.send(true to 5)
+            refreshChannel.send(false to 6)
+            refreshChannel.send(true to 7)
+            refreshChannel.close()
+            val fullStream = fullDeferred.await()
+            val partialStream = partialDeferred.await()
+
+            assertEquals(
+                7,
+                fullStream.size,
+                "Full stream should contain all events"
+            )
+            assertEquals(
+                listOf(false to 4, true to 5, false to 6),
+                partialStream,
+                "Partial stream should include up until first true false pair"
+            )
+        }
+    }
+}
\ No newline at end of file