Swipe (#24)

* Test emulator

* Update readme

* Update fastadapter and about listing

* Make faq parser asynchronous

* Modularize about panels

* Add basis for faq

* Test and finalize the faq panel

* Update readme

* Update changelog

* Remove emulator for now

* Update sample

* Change back to manual versioning to avoid suggestion errors

* Add awesome-kt banner

* Fix faq background color

* Fix merge conflicts 2

* Add waffle badge

* Update readme

* Fix lint

* Create FileUtils and NotificationUtils

* Remove frost hardcode

* Fix simple date

* Update swipe to use weak references

* Initializing test dependencies

* Update to gradle 4.1

* Fix lint warnings

* Drop back down and fix errors

* Finalize swipe with example

* Finalize weak reference and ordering

* Update test code

* Make loggers inline

15 files changed, 191 insertions, 59 deletions

diff --git a/core/src/main/kotlin/ca/allanwang/kau/kotlin/Streams.kt b/core/src/main/kotlin/ca/allanwang/kau/kotlin/Streams.kt
new file mode 100644
index 0000000..5dc44a8
--- /dev/null
+++ b/core/src/main/kotlin/ca/allanwang/kau/kotlin/Streams.kt
@@ -0,0 +1,17 @@
+package ca.allanwang.kau.kotlin
+
+/**
+ * Created by Allan Wang on 2017-08-05.
+ */
+
+/**
+ * Replica of [Vector.removeIf] in Java
+ * Since we don't have access to the internals of our extended class,
+ * We will simply iterate and remove when the filter returns {@code false}
+ */
+@Synchronized inline fun <T, C : MutableIterable<T>> C.kauRemoveIf(filter: (item: T) -> Boolean): C {
+    val iter = iterator()
+    while (iter.hasNext())
+        if (filter(iter.next())) iter.remove()
+    return this
+}
\ No newline at end of file
diff --git a/core/src/main/kotlin/ca/allanwang/kau/logging/TimberLogger.kt b/core/src/main/kotlin/ca/allanwang/kau/logging/TimberLogger.kt
index e0f6cae..4c6d655 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/logging/TimberLogger.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/logging/TimberLogger.kt
@@ -1,3 +1,5 @@
+@file:Suppress("NOTHING_TO_INLINE")
+
 package ca.allanwang.kau.logging
 
 import timber.log.Timber
@@ -9,11 +11,11 @@ import timber.log.Timber
  * Timber extension that will embed the tag as part of the message for each log item
  */
 open class TimberLogger(tag: String) {
-    internal val TAG = "$tag: %s"
-    fun e(s: String) = Timber.e(TAG, s)
-    fun e(t: Throwable?, s: String = "error") = if (t == null) e(s) else Timber.e(t, TAG, s)
-    fun d(s: String) = Timber.d(TAG, s)
-    fun i(s: String) = Timber.i(TAG, s)
-    fun v(s: String) = Timber.v(TAG, s)
-    fun eThrow(s: String) = e(Throwable(s))
+    val TAG = "$tag: %s"
+    inline fun e(s: String) = Timber.e(TAG, s)
+    inline fun e(t: Throwable?, s: String = "error") = if (t == null) e(s) else Timber.e(t, TAG, s)
+    inline fun d(s: String) = Timber.d(TAG, s)
+    inline fun i(s: String) = Timber.i(TAG, s)
+    inline fun v(s: String) = Timber.v(TAG, s)
+    inline fun eThrow(s: String) = e(Throwable(s))
 }
\ No newline at end of file
diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/RelativeSlider.kt b/core/src/main/kotlin/ca/allanwang/kau/swipe/RelativeSlider.kt
index 2ffb2ef..f14f5cf 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/swipe/RelativeSlider.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/RelativeSlider.kt
@@ -1,7 +1,5 @@
 package ca.allanwang.kau.swipe
 
-import ca.allanwang.kau.kotlin.nonReadable
-
 /**
  * Created by Mr.Jude on 2015/8/26.
  *
@@ -9,13 +7,12 @@ import ca.allanwang.kau.kotlin.nonReadable
  *
  * Helper class to give the previous activity an offset as the main page is pulled
  */
-class RelativeSlider(var curPage: SwipeBackPage) : SwipeListener {
+internal class RelativeSlider(var curPage: SwipeBackPage) : SwipeListener {
 
     var offset = 0f
 
     var enabled: Boolean
-        @Deprecated(level = DeprecationLevel.ERROR, message = "Cannot use enabled as getter")
-        get() = nonReadable()
+        get() = curPage.hasListener(this)
         set(value) {
             if (value) curPage.addListener(this)
             else curPage.removeListener(this)
diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackHelper.kt b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackHelper.kt
index 503f1fc..0859ac5 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackHelper.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackHelper.kt
@@ -2,27 +2,27 @@ package ca.allanwang.kau.swipe
 
 import android.app.Activity
 import ca.allanwang.kau.R
+import ca.allanwang.kau.kotlin.kauRemoveIf
+import ca.allanwang.kau.logging.KL
 import ca.allanwang.kau.swipe.SwipeBackHelper.onDestroy
 import java.util.*
 
-class SwipeBackException(message: String = "You Should call kauSwipeOnCreate() first") : RuntimeException(message)
+internal class SwipeBackException(message: String = "You Should call kauSwipeOnCreate() first") : RuntimeException(message)
 
 /**
  * Singleton to hold our swipe stack
  * All activity pages held with strong references, so it is crucial to call
  * [onDestroy] whenever an activity should be disposed
  */
-object SwipeBackHelper {
+internal object SwipeBackHelper {
 
     private val pageStack = Stack<SwipeBackPage>()
 
-    private operator fun get(activity: Activity): SwipeBackPage
-            = pageStack.firstOrNull { it.activity === activity } ?: throw SwipeBackException()
-
-    fun getCurrentPage(activity: Activity): SwipeBackPage = this[activity]
+    private operator fun get(activity: Activity): SwipeBackPage?
+            = pageStack.firstOrNull { it.activityRef.get() === activity }
 
     fun onCreate(activity: Activity, builder: SwipeBackContract.() -> Unit = {}) {
-        val page = pageStack.firstOrNull { it.activity === activity } ?: pageStack.push(SwipeBackPage(activity).apply { builder() })
+        val page = this[activity] ?: pageStack.push(SwipeBackPage(activity).apply { builder() })
         val startAnimation: Int = when (page.edgeFlag) {
             SWIPE_EDGE_LEFT -> R.anim.kau_slide_in_right
             SWIPE_EDGE_RIGHT -> R.anim.kau_slide_in_left
@@ -30,23 +30,28 @@ object SwipeBackHelper {
             else -> R.anim.kau_slide_in_top
         }
         activity.overridePendingTransition(startAnimation, 0)
+        KL.v("KauSwipe onCreate ${activity.localClassName}")
     }
 
-    fun onPostCreate(activity: Activity) = this[activity].onPostCreate()
+    fun onPostCreate(activity: Activity) {
+        this[activity]?.onPostCreate() ?: throw SwipeBackException()
+        KL.v("KauSwipe onPostCreate ${activity.localClassName}")
+    }
 
     fun onDestroy(activity: Activity) {
-        val page: SwipeBackPage = this[activity]
-        pageStack.remove(page)
-        page.activity = null
+        val page: SwipeBackPage? = this[activity]
+        pageStack.kauRemoveIf { it.activityRef.get() == null || it === page }
+        page?.activityRef?.clear()
+        KL.v("KauSwipe onDestroy ${activity.localClassName}")
     }
 
-    fun finish(activity: Activity) = this[activity].scrollToFinishActivity()
+    fun finish(activity: Activity) = this[activity]?.scrollToFinishActivity()
 
-    internal fun getPrePage(activity: SwipeBackPage): SwipeBackPage? {
-        val index = pageStack.indexOf(activity)
-        return if (index > 0) pageStack[index - 1] else null
+    internal fun getPrePage(page: SwipeBackPage): SwipeBackPage? {
+        //clean invalid pages
+        pageStack.kauRemoveIf { it.activityRef.get() == null }
+        return pageStack.getOrNull(pageStack.indexOf(page) - 1)
     }
-
 }
 
 /**
diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt
index 1474c1a..51cd17f 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt
@@ -10,6 +10,7 @@ import android.view.MotionEvent
 import android.view.View
 import android.view.ViewGroup
 import android.widget.FrameLayout
+import ca.allanwang.kau.logging.KL
 import ca.allanwang.kau.utils.adjustAlpha
 import ca.allanwang.kau.utils.navigationBarColor
 import ca.allanwang.kau.utils.statusBarColor
@@ -22,8 +23,8 @@ import java.lang.ref.WeakReference
  * If an edge detection occurs, this layout consumes all the touch events
  * Use the [swipeEnabled] toggle if you need the scroll events on the same axis
  */
-class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null, defStyle: Int = 0
-) : FrameLayout(context, attrs, defStyle), SwipeBackContract {
+internal class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null, defStyle: Int = 0
+) : FrameLayout(context, attrs, defStyle), SwipeBackContract, SwipeBackContractInternal {
 
     override val swipeBackLayout: SwipeBackLayout
         get() = this
@@ -51,7 +52,7 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu
 
     override var disallowIntercept = false
 
-    private var contentView: View? = null
+    private lateinit var contentViewRef: WeakReference<View>
 
     private val dragHelper: ViewDragHelper
 
@@ -156,16 +157,6 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu
         addListener(chromeFadeListener)
     }
 
-
-    /**
-     * Set up contentView which will be moved by user gesture
-
-     * @param view
-     */
-    private fun setContentView(view: View) {
-        contentView = view
-    }
-
     override fun setEdgeSizePercent(swipeEdgePercent: Float) {
         edgeSize = ((if (horizontal) resources.displayMetrics.widthPixels else resources.displayMetrics.heightPixels) * swipeEdgePercent).toInt()
     }
@@ -181,6 +172,7 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu
 
     /**
      * Removes a listener from the set of listeners
+     * and scans our list for invalid ones
 
      * @param listener
      */
@@ -194,10 +186,27 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu
     }
 
     /**
+     * Checks if a listener exists in our list,
+     * and remove invalid ones at the same time
+     */
+    override fun hasListener(listener: SwipeListener): Boolean {
+        val iter = listeners.iterator()
+        while (iter.hasNext()) {
+            val l = iter.next().get()
+            if (l == null)
+                iter.remove()
+            else if (l == listener)
+                return true
+        }
+        return false
+    }
+
+    /**
      * Scroll out contentView and finish the activity
      */
     override fun scrollToFinishActivity() {
-        val childWidth = contentView!!.width
+        val contentView = contentViewRef.get() ?: return KL.e("KauSwipe cannot scroll to finish as contentView is null. Is onPostCreate called?")
+        val childWidth = contentView.width
         val top = 0
         val left = childWidth + OVERSCROLL_DISTANCE
         dragHelper.smoothSlideViewTo(contentView, left, top)
@@ -224,6 +233,7 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu
     }
 
     override fun onLayout(changed: Boolean, left: Int, top: Int, right: Int, bottom: Int) {
+        val contentView = contentViewRef.get() ?: return KL.e("KauSwipe cannot change layout as contentView is null. Is onPostCreate called?")
         inLayout = true
         val xOffset: Int
         val yOffset: Int
@@ -234,7 +244,7 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu
             xOffset = 0
             yOffset = contentOffset
         }
-        contentView?.layout(xOffset, yOffset, xOffset + contentView!!.measuredWidth, yOffset + contentView!!.measuredHeight)
+        contentView.layout(xOffset, yOffset, xOffset + contentView.measuredWidth, yOffset + contentView.measuredHeight)
         inLayout = false
     }
 
@@ -243,7 +253,7 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu
     }
 
     override fun drawChild(canvas: Canvas, child: View, drawingTime: Long): Boolean {
-        val drawContent = child === contentView
+        val drawContent = child === contentViewRef.get()
         val ret = super.drawChild(canvas, child, drawingTime)
         if (scrimOpacity > 0 && drawContent && dragHelper.viewDragState != ViewDragHelper.STATE_IDLE)
             drawScrim(canvas, child)
@@ -272,7 +282,7 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu
         val contentChild = content.getChildAt(0)
         content.removeView(contentChild)
         addView(contentChild)
-        setContentView(contentChild)
+        contentViewRef = WeakReference(contentChild)
         content.addView(this)
     }
 
@@ -286,6 +296,7 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu
         content.removeView(this)
         removeView(contentChild)
         content.addView(contentChild)
+        contentViewRef.clear()
     }
 
     override fun computeScroll() {
@@ -324,10 +335,11 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu
 
         override fun onViewPositionChanged(changedView: View, left: Int, top: Int, dx: Int, dy: Int) {
             super.onViewPositionChanged(changedView, left, top, dx, dy)
+            val contentView = contentViewRef.get() ?: return KL.e("KauSwipe cannot change view position as contentView is null; is onPostCreate called?")
             //make sure that we are using the proper axis
             scrollPercent = Math.abs(
-                    if (horizontal) left.toFloat() / contentView!!.width
-                    else (top.toFloat() / contentView!!.height))
+                    if (horizontal) left.toFloat() / contentView.width
+                    else (top.toFloat() / contentView.height))
             contentOffset = if (horizontal) left else top
             invalidate()
             if (scrollPercent < scrollThreshold && !isScrollOverValid)
diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackPage.kt b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackPage.kt
index 81ddb62..3132f8c 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackPage.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackPage.kt
@@ -4,15 +4,17 @@ import android.app.Activity
 import android.graphics.Color
 import android.graphics.drawable.ColorDrawable
 import android.view.ViewGroup
+import ca.allanwang.kau.logging.KL
+import java.lang.ref.WeakReference
 
 /**
  * Created by Mr.Jude on 2015/8/3.
  *
  * Updated by Allan Wang on 2017/07/05
  */
-class SwipeBackPage(activity: Activity) : SwipeBackContract by SwipeBackLayout(activity) {
+internal class SwipeBackPage(activity: Activity) : SwipeBackContractInternal by SwipeBackLayout(activity) {
 
-    var activity: Activity? = activity
+    var activityRef = WeakReference(activity)
     var slider: RelativeSlider
 
     /**
@@ -38,8 +40,9 @@ class SwipeBackPage(activity: Activity) : SwipeBackContract by SwipeBackLayout(a
         }
 
     private fun handleLayout() {
-        if (swipeEnabled) swipeBackLayout.attachToActivity(activity!!)
-        else swipeBackLayout.removeFromActivity(activity!!)
+        val activity = activityRef.get() ?: return KL.v("KauSwipe activity ref gone during handleLayout")
+        if (swipeEnabled) swipeBackLayout.attachToActivity(activity)
+        else swipeBackLayout.removeFromActivity(activity)
     }
 
     fun setClosePercent(percent: Float): SwipeBackPage {
@@ -49,6 +52,10 @@ class SwipeBackPage(activity: Activity) : SwipeBackContract by SwipeBackLayout(a
 
 }
 
+internal interface SwipeBackContractInternal : SwipeBackContract {
+    val swipeBackLayout: SwipeBackLayout
+}
+
 interface SwipeBackContract {
     /**
      * Toggle main touch intercept
@@ -59,7 +66,6 @@ interface SwipeBackContract {
      * This dynamically fades as the page gets closer to exiting
      */
     var scrimColor: Int
-    val swipeBackLayout: SwipeBackLayout
     var edgeSize: Int
     /**
      * Set the flag for which edge the page is scrolling from
@@ -92,7 +98,9 @@ interface SwipeBackContract {
      * Sets edge size based on screen size
      */
     fun setEdgeSizePercent(swipeEdgePercent: Float)
+
     fun addListener(listener: SwipeListener)
     fun removeListener(listener: SwipeListener)
+    fun hasListener(listener: SwipeListener): Boolean
     fun scrollToFinishActivity()
 }
\ No newline at end of file
diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelper.java b/core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelper.java
index 3368e10..566e9e5 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelper.java
+++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelper.java
@@ -28,7 +28,7 @@ import static ca.allanwang.kau.swipe.SwipeBackHelperKt.SWIPE_EDGE_TOP;
  * This is an extension of {@link android.support.v4.widget.ViewDragHelper}
  * Along with additional methods defined in {@link ViewDragHelperExtras}
  */
-public class ViewDragHelper implements ViewDragHelperExtras {
+class ViewDragHelper implements ViewDragHelperExtras {
     private static final String TAG = "ViewDragHelper";
 
     /**
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/Const.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/Const.kt
index dad01f1..889f347 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/Const.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/Const.kt
@@ -1,14 +1,16 @@
 package ca.allanwang.kau.utils
 
+import android.support.v4.widget.ViewDragHelper
+
 /**
  * Created by Allan Wang on 2017-06-08.
  */
 const val ANDROID_NAMESPACE = "http://schemas.android.com/apk/res/android"
 
-const val KAU_LEFT = 1
-const val KAU_TOP = 2
-const val KAU_RIGHT = 4
-const val KAU_BOTTOM = 8
+const val KAU_LEFT = ViewDragHelper.EDGE_LEFT
+const val KAU_RIGHT = ViewDragHelper.EDGE_RIGHT
+const val KAU_TOP = ViewDragHelper.EDGE_TOP
+const val KAU_BOTTOM = ViewDragHelper.EDGE_BOTTOM
 const val KAU_HORIZONTAL = KAU_LEFT or KAU_RIGHT
 const val KAU_VERTICAL = KAU_TOP or KAU_BOTTOM
 const val KAU_ALL = KAU_HORIZONTAL or KAU_VERTICAL
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/FileUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/FileUtils.kt
new file mode 100644
index 0000000..25e0519
--- /dev/null
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/FileUtils.kt
@@ -0,0 +1,33 @@
+package ca.allanwang.kau.utils
+
+import android.content.Context
+import android.os.Environment
+import java.io.File
+import java.io.IOException
+import java.io.InputStream
+import java.text.SimpleDateFormat
+import java.util.*
+
+/**
+ * Created by Allan Wang on 2017-08-04.
+ */
+@Throws(IOException::class)
+fun createMediaFile(prefix: String, extension: String): File {
+    val timeStamp = SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault()).format(Date())
+    val imageFileName = "${prefix}_${timeStamp}_"
+    val storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)
+    val frostDir = File(storageDir, prefix)
+    if (!frostDir.exists()) frostDir.mkdirs()
+    return File.createTempFile(imageFileName, extension, frostDir)
+}
+
+@Throws(IOException::class)
+fun Context.createPrivateMediaFile(prefix: String, extension: String): File {
+    val timeStamp = SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault()).format(Date())
+    val imageFileName = "${prefix}_${timeStamp}_"
+    val storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES)
+    return File.createTempFile(imageFileName, extension, storageDir)
+}
+
+fun File.copyFromInputStream(inputStream: InputStream)
+        = inputStream.use { input -> outputStream().use { output -> input.copyTo(output) } }
\ No newline at end of file
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/NotificationUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/NotificationUtils.kt
new file mode 100644
index 0000000..23a8370
--- /dev/null
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/NotificationUtils.kt
@@ -0,0 +1,11 @@
+package ca.allanwang.kau.utils
+
+import android.content.Context
+import android.support.v4.app.NotificationManagerCompat
+
+
+/**
+ * Created by Allan Wang on 2017-08-04.
+ */
+fun Context.cancelNotification(notifId: Int)
+        = NotificationManagerCompat.from(this).cancel(notifId)
\ No newline at end of file
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/PackageUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/PackageUtils.kt
index 42d150e..538208d 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/PackageUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/PackageUtils.kt
@@ -1,6 +1,5 @@
 package ca.allanwang.kau.utils
 
-import android.annotation.SuppressLint
 import android.content.Context
 import android.content.pm.PackageManager
 import android.os.Build
diff --git a/core/src/main/kotlin/ca/allanwang/kau/utils/TransitionUtils.kt b/core/src/main/kotlin/ca/allanwang/kau/utils/TransitionUtils.kt
index fa062f7..1f4536b 100644
--- a/core/src/main/kotlin/ca/allanwang/kau/utils/TransitionUtils.kt
+++ b/core/src/main/kotlin/ca/allanwang/kau/utils/TransitionUtils.kt
@@ -6,9 +6,9 @@ import android.support.annotation.TransitionRes
 import android.support.transition.AutoTransition
 import android.support.transition.TransitionInflater
 import android.support.transition.TransitionManager
-import android.support.transition.Transition as SupportTransition
 import android.transition.Transition
 import android.view.ViewGroup
+import android.support.transition.Transition as SupportTransition
 
 /**
  * Created by Allan Wang on 2017-06-24.
diff --git a/core/src/test/kotlin/ca/allanwang/kau/kotlin/LazyResettableTest.kt b/core/src/test/kotlin/ca/allanwang/kau/kotlin/LazyResettableTest.kt
index 1997bd1..2025422 100644
--- a/core/src/test/kotlin/ca/allanwang/kau/kotlin/LazyResettableTest.kt
+++ b/core/src/test/kotlin/ca/allanwang/kau/kotlin/LazyResettableTest.kt
@@ -7,6 +7,8 @@ import kotlin.test.assertNotEquals
 
 /**
  * Created by Allan Wang on 2017-07-29.
+ *
+ * Test code for [LazyResettable]
  */
 class LazyResettableTest {
 
diff --git a/core/src/test/kotlin/ca/allanwang/kau/kotlin/StreamsTest.kt b/core/src/test/kotlin/ca/allanwang/kau/kotlin/StreamsTest.kt
new file mode 100644
index 0000000..1c40f57
--- /dev/null
+++ b/core/src/test/kotlin/ca/allanwang/kau/kotlin/StreamsTest.kt
@@ -0,0 +1,42 @@
+package ca.allanwang.kau.kotlin
+
+import org.junit.Test
+import kotlin.test.assertEquals
+
+/**
+ * Created by Allan Wang on 2017-08-05.
+ *
+ * Test code for [kauRemoveIf]
+ */
+class StreamsTest {
+
+    @Test
+    fun basic() {
+        val items = mutableListOf(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
+        items.kauRemoveIf { it % 2 == 0 }
+        assertEquals(listOf(1, 3, 5, 7, 9), items)
+    }
+
+    @Test
+    fun objectReference() {
+        data class Potato(val id: Int)
+
+        val thePotato = Potato(9)
+        val items = mutableListOf<Potato>()
+        val result = mutableListOf<Potato>()
+        for (i in 0..11) {
+            val potato = Potato(i)
+            items.add(potato)
+            result.add(potato)
+        }
+        items.add(3, thePotato)
+        assertEquals(result.size + 1, items.size, "Invalid list addition")
+        assertEquals(2, items.filter { it.id == 9 }.size, "Invalid number of potatoes with id 9")
+        items.kauRemoveIf { it === thePotato } //removal by reference
+        assertEquals(result.size, items.size, "Invalid list size after removal")
+        assertEquals(result, items)
+        items.kauRemoveIf { it == thePotato } //removal by equality
+        assertEquals(result.size - 1, items.size, "Invalid list removal based on equality")
+    }
+
+}
\ No newline at end of file
diff --git a/core/src/test/kotlin/ca/allanwang/kau/utils/UtilsTest.kt b/core/src/test/kotlin/ca/allanwang/kau/utils/UtilsTest.kt
index 071ee9c..ce2b757 100644
--- a/core/src/test/kotlin/ca/allanwang/kau/utils/UtilsTest.kt
+++ b/core/src/test/kotlin/ca/allanwang/kau/utils/UtilsTest.kt
@@ -6,6 +6,8 @@ import kotlin.test.assertEquals
 
 /**
  * Created by Allan Wang on 2017-06-23.
+ *
+ * Misc test code
  */
 class UtilsTest {