Closes #6369: Add ThrowProperty to support-test

components/feature/customtabs/src/test/java/mozilla/components/feature/customtabs/feature/CustomTabSessionTitleObserverTest.kt

@@ -8,6 +8,7 @@ import androidx.test.ext.junit.runners.AndroidJUnit4
 import mozilla.components.browser.session.Session
 import mozilla.components.concept.toolbar.AutocompleteDelegate
 import mozilla.components.concept.toolbar.Toolbar
+import mozilla.components.support.test.ThrowProperty
 import mozilla.components.support.test.mock
 import org.junit.Assert.assertEquals
 import org.junit.Test
@@ -15,8 +16,6 @@ import org.junit.runner.RunWith
 import org.mockito.Mockito
 import org.mockito.Mockito.never
 import org.mockito.Mockito.verify
-import kotlin.properties.ReadWriteProperty
-import kotlin.reflect.KProperty
 
 @RunWith(AndroidJUnit4::class)
 class CustomTabSessionTitleObserverTest {
@@ -86,12 +85,4 @@ class CustomTabSessionTitleObserverTest {
         override fun displayMode() = Unit
         override fun editMode() = Unit
     }
-
-    private class ThrowProperty<T> : ReadWriteProperty<Any, T> {
-        override fun getValue(thisRef: Any, property: KProperty<*>): T =
-            throw UnsupportedOperationException("Cannot get $property")
-
-        override fun setValue(thisRef: Any, property: KProperty<*>, value: T) =
-            throw UnsupportedOperationException("Cannot set $property")
-    }
 }

components/support/test/src/main/java/mozilla/components/support/test/ThrowProperty.kt

+package mozilla.components.support.test
+
+import kotlin.properties.ReadWriteProperty
+import kotlin.reflect.KProperty
+
+/**
+ * A [ReadWriteProperty] implementation for creating stub properties.
+ */
+class ThrowProperty<T> : ReadWriteProperty<Any, T> {
+    override fun getValue(thisRef: Any, property: KProperty<*>): T =
+            throw UnsupportedOperationException("Cannot get $property")
+
+    override fun setValue(thisRef: Any, property: KProperty<*>, value: T) =
+            throw UnsupportedOperationException("Cannot set $property")
+}

components/support/test/src/test/java/mozilla/components/support/test/ThrowPropertyTest.kt

+package mozilla.components.support.test.robolectric.mozilla.components.support.test
+
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import mozilla.components.support.test.ThrowProperty
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class ThrowPropertyTest {
+    private val testProperty = "test"
+    @Test(expected = UnsupportedOperationException::class)
+    fun `exception thrown when get value is called`() {
+        val throwProperty = ThrowProperty<String>()
+        throwProperty.getValue(testProperty, ::testProperty)
+    }
+
+    @Test(expected = UnsupportedOperationException::class)
+    fun `exception thrown when set value is called`() {
+        val throwProperty = ThrowProperty<String>()
+        throwProperty.setValue(testProperty, ::testProperty, "test1")
+    }
+}
\ No newline at end of file